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ASPHALTS

AND

ALLIED SUBSTANCES

Their Occurrence, Modes of Production,
Uses in the dirts and Methods of Testing

BY
HERBERT ABRAHAM

President^ The Rnberoid Co.; President ', Asphalt Shingle and

Roofing Industry

FOURTH EDITION

NEW YORK

D. VAN NOSTRAND COMPANY, INC.

250 FOURTH AVENUE

BY
D. VAN NOSTRAND COMPANY

All rights reserved. No part of this book may
be reproduced in any form without permission
in writing from the publisher, except by a
reviewer who may quote brief passages in a
review to be printed in a magazine or newspaper.

First Published, August 1918

Second Edition, August 1920

Third Edition, November 1929

Reprinted, April 1932

Fourth Edition, January 1938

PRINTED IN U. 3. A.

PRESS OF

BRAUNWORTH & CO.. INC.
BUILDERS OF BOOKS
BRIDGEPORT. CONN.

PREFACE TO FOURTH EDITION

The present edition of "Asphalts and Allied Substances" has
been revised in several material respects. Although in the main,
the textual sequence of the earlier editions has been followed, the
subject matter has been amplified so as to cover the ground more
intensively from the earliest dawn of civilization, down to the very
last word in this rapidly growing branch of technology.

Several new chapters have been added. The section relating to
"Methods of Testing" has been completely rewritten to conform
with the most recent practices. References to patents and to the gen-
eral literature have been brought up to date, and more than 12,000
such citations have been segregated in an appendix at the end of the
volume, where they would not interfere with the continuity of the
text and yet be readily accessible to the interested reader. The "Bib-
liography" has likewise been expanded to embrace more than 900
treatises.

No effort has been spared to make this new edition as compre-
hensive as the limitations of space and the author's available time
have permitted.

HERBERT ABRAHAM.

NEW YORK CITY,

September 15, 1937.

PREFACE TO THIRD EDITION

During the decade which has elapsed since the publication of the
Second Edition of <4 Asphalts and Allied Substances/' the technology
of bituminous substances has made great strides under the pressure
of rapidly increasing production. The output of crude petroleum
has not only increased- by leaps and bounds, but has gravitated to-
wards oil-fields yielding a greater percentage output of asphalt. Sim-
ilarly, coal tar and coal-tar pitch have been produced in larger
amounts, because of the widespread introduction of equipment for
recovering these valuable by-products.

Accordingly, the supply of petroleum asphalt and coal-tar resid-
uals has more than kept pace with their utilization in the arts, and
this has been reflected by a substantial reduction in their market
price. Not only has this condition rendered these substances avail-
able to a larger consuming field, but it has also served to stimulate
inventors to adapt them to new uses.

The increasing commercial importance of bituminous substances
has been evidenced by greater efforts to perfect and standardize
their methods of test, through such agencies as The Federal Speci-
fication Board (organized by the United States Government), and
many scientific societies, including especially the American Society
for Testing Materials, through w r hose courtesy the author has been
given permission to reprint their specifications and tests in this book.

To keep pace with this rapidly developing art, it has accordingly
been necessary to rewrite the book completely, and thereby bring it
up-to-date.

HERBERT ABRAHAM

NEW YORK Cn%
November i, 1929*

vii

PREFACE TO FIRST EDITION

This treatise has been written for those interested in the fabrica-
tion, merchandising and application of bituminous products. It
embraces: (i) methods serving as a guide for the works chemist
engaged in testing and analyzing raw and manufactured products;
(2 ) data for assisting the refinery or factory superintendent in blend-
ing and compounding mixtures; (3) information enabling the am-
bitious salesman to enlarge his knowledge concerning the scope and
limitations of the articles he vends; and (4) the principles underly-
ing the practical application of bituminous products for structural
purposes, of interest to the engineer, contractor and architect. Sub-
ject-matter of sole value to the technical man has been segregated in
Part V, u Methods of Testing," excepting the outline of the "Chem-
istry of Bituminous Substances" appearing in Chapter III. These
sections, however, may be passed over by the non-technical man,
without interfering materially with the continuity of the work.

In view of the vast amount of ground covered in this volume, and
fully realizing the limitations of his proficiency in some of its
branches and ramifications, the author has taken it upon himself to
draw freely from contemporary text-books and journal articles. In
such instances, his endeavor has been to place due credit where it
belongs, by referring to the source of such extraneous information.
Nevertheless, there has been included a substantial amount of orig-
inal data accumulated by the author during the past nineteen years,
most of which appears in print herein for the first time.

Topics which have been ably presented in other reference books,
as for example the technology of pavements, etc., have purposely
been subordinated to those concerning which little data have hitherto
been available. To the latter belong such subjects as petroleum
asphalts ; fatty-acid pitches ; bituminized roofings, floorings and other
fabrics; bituminous paints, cements, varnishes and japans.

Certain branches of the industry have developed along different
lines in Europe than has been the case in this country, especially

X PREFACE TO FIRST EDITION

the treatment of peat and lignite (Chapter XV), also pyrobitumin-
ous shales (Chapter XVI) . In such instances, the methods in vogue
abroad before the great war are described with more or less detail.
It must be borne in mind in this connection, that the war has mate-
rially interfered with the prosecution of these industries abroad, and
the data presented should be so construed, even though not specific-
ally stated in the text.

Whereas the greatest pains have been taken to establish the ac-
curacy of every assertion, as well as the authenticity of every alleged
fact, the author does not flatter himself that he has escaped the
pitfalls which must perforce beset the path of a writer who under-
takes to delve into a subject as complicated as the one under consid-
eration, concerning which there are so many divergent views.

Appreciation is expressed for the valuable suggestions and assist-
ance rendered by W. A. Hamor, D. R. Steuart, Prevost Hubbard,
S. R. Church, E. B. Cobb, David Wesson, Clifford Richardson, S. C.
Ells, and the author's immediate associates.

HERBERT ABRAHAM.

NEW YORK CITY,
July i, 1918.

TABLE OF CONTENTS

PART I GENERAL CONSIDERATIONS
CHAPTER I

PAGE

HISTORICAL REVIEW x

Origin of the Words "Asphalt," "Bitumen" and "Pitch" Fossils Preserved
by Means of Asphalt Use of Asphalt by the Sumerians (about 3800 to 2500
B.C.) King Sargon of Accad (about 3800 B.C.) Manishtusu King of Kish
(about 3600 B.C.) Ornaments (about 3500 B.C.) At Tell-Asmar in Eshunna
(3200 to 2900 B.C.) Lugal-daudu King of A dab (about 3000 B.C.) Ente-
mena of Shirpula (about 2850 B.C.) Ur-Nind King of Lagash (about 2800
B.C.) Ornaments and Sculptured Objects (2800 to 2500 B.C.) Gudea of
Lagash (about 2700 B.C.) Tablets of Gilgamish (about 2500 B.C.) Bur-
Sin King of Ur (about 2500 B.C.) Use of Asphalt by Pre-historic Races
in India (about 3000 B.C.) Use of Asphalt by the Early Egyptians (2500
to 1500 B.C.) Use of Asphalt in Biblical Times (2500 to 1500 B.C.) Use
of Asphalt by the Babylonians (2500 to 538 B.C.) King Khammurabi (about
2200 B.C.) Queen S emir amis (about 700 B.C.) King Nabopolassar (625 to
604 B.C.) King Nebuchadnezzar (604 to 561 B.C.) Use of Asphalt by the
Assyrians (1400 to 607 B.C.) King Adad-Nirari 1 (about 1300 B.C.) King
Tukulti-Ninurta II (890 to 884 B.C.) King Sargon (722 to 705 B.C.)
King Sennacherib (704 to 682 B.C.) Use of Asphalt in Constructing Lake-
Dwellings (about 1000 B.C.) References to Bituminous Substances by Greek
and Roman Writers (500 B.C. to 817 A.D.) Herodotus (484-425 B.C.)
Thucydides (471-401 B.C.) Hippocrates (460-377 B.C.) Xenophon (430-
357 B.C.) Aristotle (384-322 B.C.) Theophrastus (372-288 B.C.) Antigonus
(about 311 B.C.) Hannibal (247-183 B.C.) Vergil (70-19 B.C.) Strabo
63 B.C. 24 A.D.) Diodorus Siculus (about 50 A.D.) Virtuvius (about 50
A.D.) Pliny the Elder (23-79 A.D.) Josephus Flavius (37-95 A.D.) Plutarch
(about 46 A.D.) Tacitus (55-117 A.D.) Aelian (Aelianus Claudius) (about
loo A.D.) Dioscorides (about 150 A.D.) Dion Cassius (155-230 A.D.)
Philostratus (The Elder) (about 200 A.D.) Geoponica (200-300 A.D.) Afri-
canus (about 300 A.D.) Ammianus Marcellinus (330-395 A.D.) Theophanes
(758-817 A.D.) About 950 A.D., Abu-L-Hasan Masudi About 985 A.D., Abd
Al Mukaddasi About 1248 AJX, Pierre de Joinville About 1300 A.D. Marco
Polo About 1350 A.D., Sir John- Mandeville 1494-1555, Georg Agricola
1498, Christopher Columbus About 1500, Use of Asphalt in Peru 1535,
Discovery of Asphalt in Cuba 1563, Cesar Fredericke 1595, Sir Walter
Raleigh- 1599, First Classification of Bituminous Substance* 1608, William
Shakespearei 6 5 6, Early Dictionary Definition of "Bitumen" 1660, John
Milton 1661, Commercial Production of Wood Tar 1672, First Accurate
Description of Persian Asphalt Deposits 1673, Discovery of Elaterite 1681,

xii TABLE OF CONTENTS

PAGE

Discovery of Coal Tar and Coal-Tar Pitch 1691, Discovery of Illuminating
Gas from Coal 1694, Discovery of Shale Tar and Shale-tar Pitch 1712-
1730, Discovery of Val de Travers, Limmer and Seyssel Asphalt Deposits
1722, First Use of Tar for Flat Roofs 1746, Invention of the Process of
Refining Coal Tar 1752, Samuel Foote 1777, First Exposition of Modern
Theory of the Origin of Asphalt 1788, Discovery of Lignite Tar 1780-
1790, Discovery of "Composition" or "Prepared" Roofing 1792-1802, Manu-
facture of Coal Gas and Coal Tar on a Large Scale 1797-1802, Exploitation
of Seyssel Asphalt in France 1815, Commercial Exploitation of Coal-tar
Solvents 1820, Manufacture of Asphalt-saturated Packing Papers in Switzer-
land 1822, Discovery of Scheereite and Hatchettite 1830, Discovery of
Paraffin Wax 1832, Coal-tar First Used for Paving 1833, Discovery of
Ozokerite 1835, First Asphalt Mastic Foot Pavements Laid in Paris 1836,
Asphalt First Used in London for Foot Pavements 1837, Publication of First
Exhaustive Treatise on the Chemistry of Asphalt 1837, Discovery of Bitu-
minous Matter in the United States 1838, Discovery of Process for Preserv-
ing Wood with Coal-tar Creosote 1838, Asphalt First Used in the United
States for Foot Pavements 1841, First Use of Wood Block Pavement 1843,
Bituminous Matters Discovered in New York State 1844-1847, First Compo-
sition Roofing in the United States 1850, Discovery of "Asphaltic Coal" in
New Brunswick, Nova Scotia 1852, First Modern Asphaltic Road 1854,
First Compressed Asphalt Roadway Laid in Paris 1858, First Modern As-
phalt Pavement Laid in Paris 1863, Discovery of Grahamite in West Vir-
ginia 1869, The First Compressed Asphalt Pavement in London 1870-1873,
First Asphalt Roadways in the United States 1876, First Trinidad Asphalt
Pavement Laid in the United States 1880, Use of Asphalt "Chewing-gum"
in Mexico 1881, Use of Chemicals for Oxidizing Coal Tars and Petroleum
Asphalts 1885, Discovery of Uintaite (Gilsonite) in Utah 1889, Discovery
of Wurtzilite in Utah 1891, Exploitation of the Bermudez Asphalt Deposit,
Venezuela 1892, Use of Bermudez Asphalt on a Large Scale 1894, Use f
Air for Oxidizing Petroleum Asphalt

CHAPTER II

TERMINOLOGY AND CLASSIFICATION OF BITUMINOUS SUBSTANCES 51

Bituminous Substances Bitumen Pyrobitumen Petroleum Mineral Wax
Asphalt Asphaltite Asphaltic Pyrobitumen Non-asphaltic Pyrobitumen
Tar Pitch Classification of Bituminous Substances.

CHAPTER III

CHEMISTRY OF BITUMINOUS SUBSTANCES 65

Composition of Non-mineral Matrix Composition of Associated Min-
eral Constituents Composition of Associated Non-mineral Constitu-
ents Behavior with Solvents Behavior on Subjecting to Heat Re-
actions with Gases Oxygenation Hydrogenation Reactions with
Acids Liquid Sulfur Dioxide Sulfuric Acid and Sulfur Trioxide Nitric
Acid Sulfuric Acid and Formaldehyde Reactions with Alkalies Reac-
tions with Metalloids Sulfur and Sulfur Dichloride Selenium Phos-
phorusHalogens Reactions with Metallic Salts.

TABLE OF CONTENTS xiii

CHAPTER IV

PAGE

GEOLOGY AND ORIGIN OF BITUMENS AND PYROBITUMENS 82

Geology Age of the Geological Formations Character of the Associated
Minerals Modes of Occurrence Springs Lakes Seepages Subterranean
Pools or Reservoirs Impregnated Rock in Strata Filling Veins Movement
of Bitumen in the Earth's Strata Hydrostatic Pressure Gas Pressure
Capillarity Gravitation Effect of Heat Origin and Metamorphosis of
Bitumens and Asphaltic Pyrobitumens Probable Origin of Bitumens
and Asphaltic Pyrobitumens Inorganic Theories Vegetable Theories Ani-
mal Theories Metamorphosis of Mineral Waxes, Asphalts, Asphaltites and
Asphallic-Pyrobitumens from Petroleum Origin and Metamorphosis of
Non-Asphaltic Pyrobitumens.

CHAPTER V

ANNUAL PRODUCTION OF BITUMINOUS SUBSTANCES AND THEIR

MANUFACTURED PRODUCTS 98

Production of Asphalts, Asphaltites and Asphaltic Pyrobitumens
World Production Production in the United States Production of Tars
and Pitches Tars Derived from Coal Tars and Pitches Derived from
Wood Other Tars and Pitches Manufactured Products Bituminous
Paving Materials Bituminous Roofing Products Asphalted Felt-base Floor
Coverings.

PART II SEMI-SOLID AND SOLID BITUMENS AND

PYROBITUMENS

CHAPTER VI

METHODS OF MINING, TRANSPORTING AND REFINING 112

Mining Methods Open-cut Quarrying Tunnelling Special Methods
Methods of Shipment and Transportation Methods of Refining De-
hydration Distillation Comminution Sedimentation Extraction
Extraction by Means of Water Extraction or Precipitation with Solvents
Methods of Storage.

CHAPTER VII

MINERAL WAXES 129

Ozokerite Europe Galicia Rumania Russia Terek Province Kuban
Province Kutais Province Tiflis Province Baku Province Kars Province
Asia State of Turkestan Siberia Philippine Islands North America
United States UtafiTexasHatchettite or Hatchettine Scheereite
Kabaite Montan Wax.

Xiv TABLE OF CONTENTS

CHAPTER VIII

PAGE

NATIVE ASPHALTS OCCURRING IN A FAIRLY PURE STATE 139

North America United States Kentucky Oklahoma Utah California
Oregon Mexico State of Tamaulipas State of Vera Cruz Cuba Prov-
ince of Matanzas Province of Santa Clara Province of Camaguey Province
of Santiago de Cuba South America Venezuela State of Bermudez State
of Zulia Europe France Department of Puy de Dome Albania Se*le-
nitza Greece Zante Russia Kutais Province Tiflis Province Uralsk
Province Asia Syria Villayet of Beirut Mesopotamia (Iraq) Hit Ain
el Maraj Ain Ma* Moura Quijarah, Ramadi and Abu Gir Asiatic Russia
Sakhalin Philippine Islands Island of Leyte.

CHAPTER IX

NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 155

North America United States Kentucky Missouri Indiana Oklahoma
Arkansas Alabama Louisiana Texas Utah Wyoming Cali-
fornia Canada Alberta Province Manitoba Province Mexico States of
Vera Cruz and Tamaulipas Cuba Province of Matanzas Province of Pinar
del Rio Province of Havana Province of Camaguey Province of Santiago
de Cuba South America Trinidad Brazil State of Parand State of
Sao Paulo Argentina Province of Jujuy Province of Chubut Province
of Mendoza Colombia Department of Bolivar Department of Antioquia
Department of Santander Department of Boyacd Equador Province of
Guayas Europe France Department of Landes Department of Gard
Department of Haute-Savoie Department of Ain Department of Basses-
Alpes Department of Puy~de-D6me Department of Haute Vienne Switzer-
land Alsace-Lorraine Spain Burgos Province Germany Province of
Hanover Province of Westphalia Province of Hessen Province of Baden
Province of Silesia Jugoslavia Province of Dalmatia Province of Herze-
govina Province of Styria Austria Province of Tyrol Hungary Prov-
ince of Bihar Czecho-Slo<vakia Province of Trencsen Provinces of Moravia
and Silesia Rumania Albania S61enitza Italy Compartment of Marches
Compartment of Abruzzi e Molise Compartment of Calabria Compart-
ment of Campania Compartment of Sicily Greece Department of Triphylia
Department of Achaia lolian Islands Department of Phocis Depart-
ment of Phthiotis Departments of Eurytania and Arta Northern Depart-
ments Portugal Province of Estremadura Spain Province of Santander
Province of Alava Province of Navarre Province of Gerona Province of
Tarragona Province of Soria Province of Burgos Province of Almeria
Province of Valencia Russia (in Europe) Simbirsk Province Kazan Prov-
ince Samara Province Terek Province Kutais Province Tiflis Province
Baku Province Asia Syria (Levant States) Vilayet of AleppoVilayet of
Beirut Vilayet of Sham Palestine- Mesopotamia (Iraq) Valiyet of Bagdad
Asiatic Russia Uralsk Province State of Turkestan Kamchatka Penin-
sulaSakhalin Island Tur key-in- Asia (Asia Minor) Anatolia Arabi a
Vilayet of El Hasa Sinai Peninsula -Egypt India Kashmir District Ha-
zara District Bel uchistan District Bombay Island China Chinese Turkes-
tan Japan -Akita Prefecture Prefectures of Yamagata, Aomori and Dis-
trict of Hokkaido Australia New South Wales Western Australia North-

TABLE OF CONTENTS XV

PAGE

ern Territory Tasmania New Zealand Dutch East Indies Buton (Boe-
ten) IslandAfrica Algeria Province of Oran Nigeria Rhodesia -Mad-
agascar.

CHAPTER X

ASPHALTITES 2Z7

GILSONITE or UINTAITE North America United States Utah Oregon-
Asia Russia Archangel Province GLANCE PITCH North America West
Indies Barbados Santo Domingo (Haiti) Cuba Province of Pinar del
Rio Province of Santa Clara Province of Camaguey Mexico State of
Vera Cruz United States Utah Central America Nicaragua District
of Chontales Salvador Department of San Miguel South America
Colombia Province of Tolima Province of Bolivar Europe Germany
Bentheim Syria (Levant States) Vilayet of Sham Palestine Mesopotamia
(Iraq) GRAHAMITE North America United States West Virginia
Texas Oklahoma Colorado Mexico State of Vera Cruz State of San
Luis Potosi State of Tamaulipas Cuba Province of Pinar del Rio Prov-
ince of Havana Province of Santa Clara South America Trinidad
Argentina Province of Mendoza Province of Neuquen Peru Province of
Tarma.

CHAPTER XI
ASPHALTIC PYROBITUMENS 202

ELATERITE England Derbyshire County Australia State of South Australia
Asiatic Russia State of Turkestan WURTZILITE United States Utah
Albertite Canada Province of New Brunswick Province of Nova Scotia
United States Utah South America Falkland Islands Germany Prov-
ince of Hanover Australia Tasmania Portuguese West Africa Province
of Angola IMPSONITE North America United States Oklahoma Ar-
kansas Nevada Michigan South America Peru Provinces of Canta
and Yauli Province of Huarochiri Brazil State of Sao Paulo Australia
West Australia.

CHAPTER XII
PYROBITUMINOUS SHALES 275

PART 1 1 ITARS AND PITCHES

CHAPTER XIII
GENERAL METHODS OF PRODUCING TARS 278

Destructive Distillation Composition of the Substance The Temperature
The Time of Heating The Pressure The Efficiency of the Condensing
System Partial Combustion with Air and Steam Partial Combustion
with a Limited Access of Air Cracking of Oil Vapors.

xvi TABLE OF CONTENTS

CHAPTER XIV

PAGE

WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH ................... 288

Wood Tar and Wood-tar Pitch Varieties of Wood Used Yields of
Distillation Hardwood Distillation Method of Distilling Refining Proc-
esses Soft (Resinous) Wood Distillation Method of Distilling Refining
Processes Hardwood Tar and Pine Tar Hardwood-tar Pitch and Pine-tar
PitchRosin Pitchr-Raw Materials Used Methods of Distilling Products
Obtained Properties of Rosin Pitch "Burgundy Pitch."

CHAPTER XV

PEAT AND LIGNITE TARS AND PITCHES .............................. 305

Peat Tar and Peat-tar Pitch Formation of Peat Varieties of Peat
Methods of Collecting Dehydrating Processes Methods of Distilling Refin-
ing Processes Properties of Peat Tar Properties of Peat-tar Pitch Lignite
Tar and Lignite-tar Pitch Varieties of Lignite Mining Methods
Methods of Distilling Products Obtained Treating Impure Lignite Proper-
ties of Lignite Tar Refining Processes Products Obtained Properties of
Lignite-tar Pitch.

CHAPTER XVI
SHALE TAR AND SHALE-TAR PITCH .................................... 2

Shale Mining Retorts Used for Distillation Pumpherston Retort Hender-
son or Broxburn Retort Methods of Recovering Shale Tar Products Ob-
tained Properties of Shale Tar Refining of Shale Tar Properties of Shale-
tar Pitch.

CHAPTER XVII

COAL TAR AND COAL-TAR PITCH ...................................... 336

Bituminous Coals Used Temperature of Treatment Production of Gas-
Works Coal Tar Retorts Used Methods of Recovery Products Obtained _
Production of Coke-oven Coal Tar Retorts Used Methods of Recovery _
Products Obtained Production of Blast-furnace Coal Tar Methods of Re-
covery Production of Producer-gas Coal Tar Products Obtained Produc-
tion of Low-temperature Tars Products Obtained Properties of Coal
Tars Methods of Dehydrating Coal Tar Settling Use of Cen-
trifugesHorizontal Stills Tube Heaters Cascade System Methods of
Distilling Coal Tar Simple Batch Stills Vacuum Distillation Steam Dis-
tillation Gas Recirculation Continuous Stills Tube Stills Collector-
Main Condensers Recovery and Treatment of Coal-tar Distillates Recovery
and Treatment of Coal-tar Residuals Commercial Varieties of Coal-tar Pitch
Pitch Coke Properties of Coal-tar Pitches Gas-works Coal-tar Pitches-
Coke-oven Coal-tar Pitch Blast-furnace Coal-tar Pitch Gas-producer Coal-
tar Pitch Low-temperature Coal-tar Bitch Anthracene Pitch Naphthol
Pitch Cresol Pitch.

TABLE OF CONTENTS XVii

CHAPTER XVIII

PAGE

WATER-GAS AND OIL-GAS TARS AND PITCHES 378

Carburetted Water-gas Tar Method of Production Properties of Water-
gas Tar Oil-gas Tars Methods of Production Pintsch Gas Oil-water
Gas Blau Gas Properties of Oil-gas Tars Refining of Water-gas and Oil-
gas Tars Properties of Water-gas-tar Pitch and Oil-gas-tar Pitch.

CHAPTER XIX

FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 386

Fatty-acid Pitch Sources from which Obtained Production of Candle and
Soap Stocks Hydrolysis by Means of Water Hydrolysis by Means of Con-
centrated Sulfuric Acid Hydrolysis by the "Mixed Process" Hydrolysis by
Means of the Sulfo-compounds Hydrolysis by Means of Ferments Refining
Vegetable Oils by Means of Alkali Refining of Cotton-seed Oil Refining
of Corn-Oil Refining Refuse Greases Refining Packing-house and Carcass-
rendering Greases Refining Bone Grease Refining Garbage and Sewage
Greases Refining Woolen-mill Waste Treatment of Wool Grease Physical
and Chemical Properties of Fatty-acid PitchesBone Tar and Bone-tar
Pitch Methods of Production Physical and Chemical Characteristics
Glycerine Pitch.

PART IFPYROGENOUS ASPHALTS AND WAXES

CHAPTER XX

PETROLEUM ASPHALTS 409

Varieties of Petroleum Asphaltic Petroleums Semi-asphaltic Petroleums
Non-asphaltic Petroleums Dehydration of Petroleum Settling Cen-
trifuging Tube-stills Distillation of Petroleum Batch Stills Steam
Distillation Dry Distillation Continuous Stills Tube or Pipe Stills
Cracking Processes Liquid Phase Cracking Tube-and-tank Process
Cross Process Holmes-Manly Process Mixed Phase Cracking Burton
Process Dubb's Process Liquid Products Semi-solid to Solid Distillates
Semi-solid to Solid Residues Residual Oils Varieties Obtained Physical
and Chemical Characteristics Blown Petroleum Asphalts Processes Used
Advantages of "Blowing" Over the Steam-distillation Process Physical and
Chemical Characteristics Sulfurized Asphalts Residual Asphalts Proc-
esses Used Physical and Chemical Characteristics Methods of Distinguish-
ing between Petroleum Asphalts and Native Asphalts Sludge Asphalts
Methods of Production Physical and Chemical Characteristics.

CHAPTER XXI

PARAFFIN WAX, WAX TAILINGS AND RESINS 466

Paraffin Wax Sources from which Obtained Physical and Chemical Char-
acteristics Wax Tailings Methods of Production Physical and Chemical
Characteristics Petroleum Resinsr Asphaltic Resins.

XViii TABLE OF CONTENTS

CHAPTER XXII

PAGE

WURTZILITE ASPHALT 472

Method of Production Still Used Depolymerization Process Grades of
Wurtzilite Asphalt Produced Chemical and Physical Characteristics.

PART V MANUFACTURED PRODUCTS AND

THEIR USES

CHAPTER XXIII

COMPOUNDING OF BITUMINOUS SUBSTANCES 476

General Considerations Hardness, Fusibility, Penetration, Approximate
Comparative Volatility, Weatherproof Properties and Efficiency of Fluxing
of Various Bituminous Substances Principles Involved in Preparing Mixtures
Binary Mixtures Softening of the Substance and Lowering its Fusing-
point Augmenting the Adhesive Properties of the Substance Increasing the
Fluidity of the Substance when Melted Effecting a More Perfect Union or
Blending of the Constituents Hardening the Substance, Raising its Fusing-
point and Increasing its Stability Rendering the Mixture Less Susceptible to
Temperature Changes Increasing the Tensile Strength of the Mixture
Making the Mixture More Weatherproof Rendering Wax-like, Unctuous
to the Feel, or Lessening the Tendency Towards Stickiness Tertiary and
Complex Mixtures Classes of Bituminous Mixtures Soft (Liquid) Bitumi-
nous Products Medium (Semi-liquid to Semi-solid) Bituminous Products
Hard (Solid) Bituminous Products Processes of Compounding Bituminous
Substances.

CHAPTER XXIV

BITUMINOUS SUBSTANCES ADMIXED WITH DISCRETE AGGRE-
GATES 494

Methods of Incorporating Discrete Aggregates Colloidal Particles Ad-
mixed Mechanically Inorganic Organic Liberated "In Situ" Inorganic
Organic Fillers (Powders) Including Pigments Inorganic Oxides
Silicates Carbonates Sulfates Phosphates Miscellaneous Rock Products
Pyrogenous Products Black Pigments Colored Pigments Organic Vege-
table Products Black Pigments Fibers Inorganic Organic Granular
Matter Inorganic Organic Coarse Mineral Aggregates Crushed
Rock, Stone, Gravel or Slag Graded Aggregates Combinations of the
Foregoing.

CHAPTER XXV

BITUMINOUS SUBSTANCES DISPERSED IN WATER 503

Types of Bituminous Dispersions Forms of Apparatus Used Charac-
ter of the Bituminous Substance Character of the Dispersing Agent
Inorganic Substances Hydroxides Oxides Silicates Sulfates Phosphates
Sulfides or Polysulfides Alkalies Miscellaneous Organic Substances Fats

TABLE OF CONTENTS xix

PAGE

and Oils Resins Soaps Sulfonated Vegetable Oils Sulfite Liquor Min-
eral-Oil Derivatives Carbonaceous Matter Alkaline Bases Proteins or Pro-
teids Albumenoids Pectins Gums and Algae Polysaccharides and Herai-
celluloses Tannins Miscellaneous Parlous Combinations Clay in Com-
bination Sodium Silicate in Combination Soaps in Combination Sulfonated
Vegetable Oils in Combination Alkaline Caseinates in Combination Glue or
Gelatine in Combination Tannic Acid in Combination Uses of Bitumin-
ous Dispersions.

CHAPTER XXVI
BITUMINOUS SUBSTANCES DISSOLVED IN SOLVENTS 514

Classes of Solvents Function of Solvents Behavior of Solvents Solubility
of Bituminous Substances Adsorption of Bituminous Substances.

CHAPTER XXVII

SOLID, SEMI-SOLID AND SEMI-LIQUID BITUMINOUS COMPOSITIONS. 526

Adhesive Compounds for Built-up Roofing and Waterproofing Work Ad-
hesive Compounds for Waterproofing Below Ground Above Ground Ad-
hesive Compounds for Built-up Roofing Work Plastic-slate Cement
Calking Compounds Bituminous Grout Bituminous Enamel for the Inside
of Steel Ships Bituminous Enamel Bituminous Primer Bituminous Enamel
for Acid-proofing Concrete Surfaces Pipe Dips and Pipe-sealing Compounds
Pipe Dips Pipe Wrappings Pipe-sealing Compounds Electrical Insulat-
ing Compounds Vacuum Impregnating Compounds Cable-splicing and Pot-
head Compounds Battery-box Compounds "Carbons" for Batteries, Electric
Lights and Armature Brushes Bituminous Rubber Substitutes Molded Com-
positions Mixtures for Small Molded Articles Preformed Joints and Wash-
ers Molded Brake-linings, Clutch-facings and Friction Elements Bitumin-
ated Cork Mixtures Battery Boxes Fibrated Bituminous Compositions
Roof Tiles Floor Tiles Floor and Step Treads Artificial Lumber and Rail-
road Ties Pipes and Conduits Burial Vaults Phonograph Records Bi-
tuminated Leather Mixtures Briquette Binders Core Compounds Miscel-
laneous Bituminous Products Bituminous Fuels Tars and Oils for the
Flotation of Ores Waterproofing Compounds for Portland-cement Mortar
and Concrete Pure Bituminous Substances Bituminous Substances in Emul-
sified Form Methods of Use Sponge Asphalt Asphalt Dust and Filaments
Asphalt Jelly.

CHAPTER XXVIII

BITUMINOUS PAVING MATERIALS 567

Bituminous Binders Liquid Asphaltic Binders Semi-solid to Solid As-
phaltic Binders Coal-tar Binders Cut-back Products Bituminous Emulsions
Mineral Aggregates Bituminous Compositions for Dust-laying
(Cold Application) Bituminous Emulsions Non-emulsified Products
General Considerations Bituminous Surfacings Surface Treatment Silt
Roads Clay Roads Sandy Roads Seal-Coats To Loose Surfaces To
Bonded Surfaces To Old Bituminous Surfaces To Non-bituminous Sur-
faces Road-Mix Wearing Course Open Aggregate ("Macadam Type")

XX TABLE OF CONTENTS

PAGE

Dense Aggregate ("Graded Type") Plant-Mix Wearing Course Open Ag-
gregate ("Macadam Type")- Dense Aggregate ("Graded Type") Bitumi-
nous Macadam Pavements Foundation Base Course Surface Course
Bituminous Emulsions Penetration Method Road-Mix Method Bitumi-
nous Concrete Pavements Foundation Base Course ("Black-base")
Surface Course, Coarsely-graded Type Surface Course, Finely-graded Type
Asphalt Emulsions Sheet-asphalt Pavements Foundation Binder and
Surface Courses General Considerations Bituminous Joint-Fillers Fill-
ing the Joints Asphalt-block Pavements Foundation Laying the Blocks
Bituminized Wood-block Pavements Methods of Impregnation Creo-
sote Preservatives Foundation Cushion Layer Filling the Joints General
Considerations Asphalt Mastic Foot-Pavements and Floors Asphalts
Used Methods of Preparation Methods of Application Asphalt Mastic
Roofs Bituminous Expansion Joints Promolded Strips Bituminized
Fabric Strips Laminated Strips Armored Strips Bituminous Rail-fillers
Asphalt Bridge-planking Bituminous Revetment.

CHAPTER XXIX

BITUMINIZED FABRICS, FELTS AND PAPERS FOR ROOFING, FLOOR-
ING, WATERPROOFING, BUILDING AND INSULATING PURPOSES 617

Prepared Sheet Roofings Felted Fabrics Rag-felt Methods of Fire-
proofing Rag-felt String-felt or Threaded-felt Asbestos Felt Woven Fa-
brics Bituminous Saturating Compositions Asphaltic Products Tar Prod-
ucts Bituminous Coating and Adhesive Compositions Fillers Black Pig-
ments Colored Pigments Inorganic Surfacings Fine Mineral Particles
Moderately Coarse Mineral Granules Coarse Mineral Granules Organic
Surfacings Saturated Felt Saturating the Fabric Tarpaulins Brattice
Cloth Tents and Awnings Waterproof Membranes Wrapping Cloth
Teredo-proof Coverings Roof Coverings for Railway Cars Prepared Roll-
roofings Single-layered Prepared Roofings Laminated Roofings Decora-
tive Roll-roofings Scalloped and Serrated Roll-roofings Asphalt Shingles
General Features Features Pertaining to Thickness Shingles Surfaced
with Mineral Granules Rear Surface Coating Shingles Surfaced with Min-
eral Granules and Coated with Hydraulic Cement Shingles Surfaced with
Slate-veneer or Tile or Asbestos-cement Shingles Surfaced with Metals
Shingles Reinforced with a Core of Sheet-metal or Wire Laminated Shingles
Combinations with Asbestos Felt Combinations Involving the Use of
Wooden Shingles Miscellaneous Forms Individual Shingles Forming
Rectangular Patterns when Laid Forming Diamond-shaped Patterns when
Laid Forming Hexagonal Patterns when Laid Forming Octagonal Patterns
when Laid Forming Circular Patterns when Laid Forming Thatched Ef-
fects when Laid Reversible Forms Strip Shingles Forming Rectangular
Patterns when Laid Forming Diamond-shaped Patterns when Laid Form-
ing Hexagonal Patterns when Laid Forming Octagonal Patterns when Laid
Forming Circular or Curved Effects when Laid Forming Thatched Effects
when Laid Forming Miscellaneous Patterns when Laid Reversible Forms
Asphalt Sidings Fastening Devices Lap-cement Nails Metal Cleats for
Roll-roofings Concealed Nailing for Roll-roofings Forming Standing Seams
Methods of Packaging Methods of Laying Roofings and Shingles Laying
the Fabric in a Single Course Built-up Roofs Laying Asphalt-shingle
Roof a Fire-resisting Properties of Prepared Roofings and Shingles Bi-,

TABLE OF CONTENTS xxi

PAGE

tuminized Floor Coverings Saturated Felt Base Method of Printing
Waterproofing Membranes Materials Used Preparing the Underly-
ing Surface Selecting and Installing the Waterproofing Membrane Pro-
tecting the Waterproofing Membrane Insulating and Building Papers
Raw Paper Stock Bituminous Saturation Bituminous Coating Compositions
Method of Manufacture Bituminized Papers for Electrical Insulation
Bituminized Papers for Wrapping and Packing Purposes Bitumin-
ized Papers for Mulching Plants and Crops Blasting Fuses Bi-
tuminized Cords and Ropes Insulation for Electrical Transmission
Wires Bituminized Fiber Conduits Asphalt Pipes Brake Linings
and Clutch-facings for Automobiles Insulating and Acoustical Felts
for Automobiles Electrical Insulating Tape Bituminized Wall-
Board Bituminous Insulating Board Acoustical Blocks Bitum-
inous Stucco-base and Plaster-board*

CHAPTER XXX

BITUMINOUS LACQUERS, CEMENTS, VARNISHES, ENAMELS AND

JAPANS 720

Bituminous Lacquers and Paints Nature of the Base Nature of the Fill-
ers and Pigments Nature of the Solvents Methods of Manufacture Types ,
of Bituminous Paints Masonry Coatings Clear Damp-proofing Paints
Black Damp-proofing Paints Stone Backing Paints for Resurfacing Prepared
Roofings Asphalt Fibrous-Roof-Coating Acid-resisting Coatings Bitumi-
nous Coatings for Metal or Wood Anti-fouling Paints Bituminous Emulsion
Paints Flooring Compositions for Cold Application Bituminous Cements
Method of Manufacture Method of Use Bituminous Varnishes
Method of Manufacture Bituminous Enamels Method of Manufacture
Cellulose-Ester Lacquers Bituminous Japans Method of Manufacture
Uses.

PART VI METHODS OF TESTING
CHAPTER XXXI *

SAMPLING 757

General Methods Definitions Sampling Crude, Refined and Blended Bi-
tuminous Substances Sampling at Place of Manufacture When Material
is Pumped under Pressure When Materials Flow by Gravity Sampling at
Point of Delivery Semi-solid or Solid Materials Liquid Materials Solid
Bituminous Materials in Crushed Fragments or Powder Sampling Bitumi-
nous Paving Materials Sampling Bituminized Fabrics Sampling
Bituminous Lacquers, Cements, Varnishes and Japans, also Bitumi-
nous Emulsions.

CHAPTER XXXII

EXAMINATION OF CRUDE, REFINED AND BLENDED BITUMINOUS

SUBSTANCES 776

Synoptical Table of Bituminous Substances Physical Characteristics
Color Color in Mass Color in Solution Homogeneity To the Eye Under
Microscope When Melted In Solution Appearance Surface when Aged

xxii TABLE OF CONTENTS

PAGE

Fracture Lustre Streak Water Absorption Diffusibility Specific Gravity
Hydrometer Method Westphal Balance Method Bottle Method Pyk-
nometer Method Analytical Balance Method Voids (Entrapped Air) Col-
loidal Capacity-^Clzy Dispersions Ultramicroscopic Count of Colloidal Par-
ticlesMechanical Tests Viscosity Engler Method Saybolt ( Furol)
Method Absolute Viscosity Hutchinson's Method Float Test Schutte
Method Falling Ball Method Alternating Stress Method Falling Coaxial
Cylinder Method Hardness or Plasticity Moh's Scale Penetrometer Con-
sistometer Susceptibility Index Ductility Dow' s Method Author's Method
Tensile Strength ( Cohesiveness) Author's Method Adhesiveness
Riehm's Method Wedmore's Method Brown's Method Surface Tension
Nellensteyn's Method Interfacial Tension Thermal Tests Thermal Con-
ductivity A.S.T.M. Method Specific Heat Heat Content Thermal Ex-
pansion A.S.T.M. Method Breaking Point Knife Test Reeve and Yea-
ger's Method Fraas Method Solidifying-PointMetzgeT's Method Soften-
ing-Point or Fusing-Point Kramer-Sarnow Method Ring-and-Ball Method
Cube Method Compression Method A.S.T.M. Method for Petrolatum
A.S.T.M. Method for Paraffin Wax Flow-Point Richardson's Method
Liquefying-Point Ubbelohde's Method Twisting-Point Taylor's Method
Volatile Matter A.S.T.M. Method Evaporation Test A.S.T.M. Method
Distillation Test A.S.T.M. Method FW/-/>o*w/ Pensky-Martens Tester-
Cleveland Tester Tag Closed Tester Tag Open Tester Burning-Point-
Fixed Carbon Solubility Tests Solubility in Carbon Bisulfide Where
the Constituents are Not to be Examined Further Where the Constituents are
to be Examined Further Carbenes Richardson's Method Solubility in
Petroleum Naphtha Insoluble in Benzol ("Free Carbon") Solubility in
Other Solvents Chemical Tests Water Substances Distilling at Low Tem-
peraturesSubstances Distilling at High Temperatures Elemental Composi-
tion Carbon Hydrogen Sulfur Nitrogen Oxygen (in Non-mineral Mat-
ter) Molecular Weight Freezing-point Method Tar Adds Contraction
Method Liberation Method Naphthalene Solid Paraffins Holders Method
Sulfonation Residue Residue Insoluble in Concentrated Sulfuric Acid-
Residue Insoluble in Water Dimethyl Sulfate Method Formolite Reaction
Nastjukoff Method Degree of MercurationSaponifiable Constituents Free
Acids (Acid Value) Lactones and Anhydrides (Lactone Value) Neutral
Fats (Ester Value) Saponification Value Separation of Saponifiable Con-
stituentsExamination of Unsaponifiable Constituents Examination of Sa-
ponifiable Constituents Glycerol ^/>^//*V Constituents Free Asphaltous
Acids Asphaltous Acid Anhydrides Asphaltenes Asphaltic Resins Oily
Constituents Diazo Reaction Graefe's Method Anthraquinone Reaction
Liebermann-Storch Reaction Colorimetric Method.

CHAPTER XXXIII

EXAMINATION OF BITUMINOUS SUBSTANCES COMBINED WITH

DISCRETE AGGREGATES IOI 7

Physical Tests of Finished Product Pawing Compositions, Asphalt Mas-
tic Bituminous Grouts, Pipe-sealing Compounds, etc. Specific Gravity-
Voids Resistance to Moisture Effect of Water on Adhesion Hardness Re-
sistance to Displacement Extrusion of Binder Under Pressure Resistance to
Impact Brittleness or Shatter Test Coefficient of Wear Molded Materials
Thickness Resistance to Moisture Tensile Strength Compressive Strength

TABLE OF CONTENTS xxiii

PAGE

Flexural Strength Distortion Under Heat Softening-Point Resistance to Im-
pact Electrical Tests Separation of Finished Product into Its Compo-
nent Parts Separation of the Bituminous Matter and Discrete Aggre-
gate Methods Suitable for Aggregates Associated with an Asphaltic Binder
Hot Extraction Method Cold Extraction Method Centrifugal Extraction
Method Method Suitable for Aggregates Associated with Coal-tar Pitch
Binder Recovery and Examination of Extracted Bituminous Matter
Separation of Bituminous Constituents Examination of the Separated
Aggregate Inorganic Aggregates Granularmetric Analysis Elutriation
Test Air-separation Test Adsorptive Capacity of Fine Fillers Specific
Gravity Organic Particles^ Fibers t Fillers t etc.

CHAPTER XXXIV

EXAMINATION OF BITUMINIZED FABRICS 1072

Physical Tests of the Finished Product Weight per Unit Area For
Saturated Felted and Woven Fabrics For Smooth-roll and Mineral-surfaced
Roll-roofing For Mineral-surfaced Shingles Thickness Strength Tensile
Strength Bursting Strength Tearing Strength Pliability Mandrel Test
Reeve and Y eager Test Resistance to Dampness Water Absorption Resis-
tance to Heat For Asphalt-saturated Fabrics For Coal-tar Saturated Fabrics
Only For Asphalt Roll-roofings and Shingles Electrical Tests Special
Tests Applicable to Insulating Tape Tensile Strength Adhesion Oven
Test Tackiness Separation of Finished Product into Its Component
Parts Separation of Bituminous Matter, Mineral Matter and Fibrous
Constituents Moisture Analysis of Saturated Fabrics (Single-layered)
Analysis of Saturated and Coated Fabrics (Single-layered) Recovery
and Examination of Extracted Coatings and Saturation Ex-
amination of the Separated Mineral Surfacing and Admixed Min-
eral Constituents Examination of the Separated Fabric Weight per
Unit Area ("Number") Uncorrected Number Moisture Corrected Number
Thickness Tensile Strength Porosity Speed with which the Felt Will
Saturate Vertical Method Horizontal Method Saturating Capacity Fiber
Composition.

CHAPTER XXXV

EXAMINATION OF BITUMINOUS SOLVENT COMPOSITIONS 1117

Physical Tests of the Finished Product RSsumt of Physical Tests Spe-
cific Gravity Viscosity Plasticity and Mobility Flash-point Spreading
Capacity and Workability Draining Test Time of Drying Hiding Power
Color Gloss Hardness, Abrasion and Adhesion Water Absorption Re-
sistance to Heat Resistance to 'Oil Resistance to Acids and Alkalies Dielec-
tric Strength Estimation, Recovery and Examination of the Solvent
Estimation and Recovery of Solvent Evaporation Method Steam Distillation
Method Examination of the Solvent Estimation, Recovery and Exam-
ination of Pigment and Filler Estimation and Recovery of Pigment and
Filler Examination of the Pigment or Filler Estimation, Recovery and
Examination of the Base Estimation and Recovery of the Base Examina-
tion of the Base.

xxiv TABLE OF CONTENTS

CHAPTER XXXVI

PAGE

EXAMINATION OF BITUMINOUS DISPERSIONS 1 132

Physical Tests of the Finished Product Method of Identification
Homogeneity Appearance Under Microscope Sieve Test Settlement Test
Stability on Aging Viscosity Demulsibility Calcium-chloride Test Fer-
rous-sulfate Test Behavior with Aggregate ("Coating Test")Miscibility
with Water Effects on Freezing Resistance to Water After Setting With-
out Aggregate When Mixed with Aggregate Separation of the Disper-
sion into its Component Parts Distillation ResidueWater and Volatile
Oils Dispersing Agents.

CHAPTER XXXVII

WEATHERING TESTS "47

Effects of WeatheringEvaporationOxidationCarbonizationPoly-
merizationEffects of Moisture Actual Weathering Test Testing Bitu-
minized Fabrics Testing Bituminous-solvent Compositions Testing Crude,
Refined or Blended Bituminous Substances Accelerated Weathering Test

Testing Bituminized Fabrics Testing Bituminous-solvent Compositions

Testing Bituminous Compositions Modified Accelerated Weathering
Test.

TEMPERATURE CONVERSION TABLE 1182

BIBLIOGRAPHY "*3

REFERENCES I2 3 1

INDEX '435

ASPHALTS AND ALLIED SUBSTANCES

PART I
GENERAL CONSIDERATIONS

CHAPTER I
HISTORICAL REVIEW

Origin of the Words "Asphalt," "Bitumen" and "Pitch."

The word "asphalt" is claimed to have been derived from the
Accadian term "asphaltu" or "sphallo," meaning "to split." It was
later adopted by the Homeric Greeks in the form of the adjective
dcr^aX^, c's, signifying "firm," "stable," "secure," and the correspond-
ing verb dcr<aAia>, tiro), meaning "to make firm or stable," "to se-
cure." It is a significant fact that the first use of asphalt by the
ancients was in the nature of a cement for securing or joining
together various objects, and it thus seems likely that the name itself
was expressive of this application. From the Greek, the word
passed into late Latin, and thence into French ("asphalte") and
English ("asphalt").

The expression "bitumen" originated in the Sanskrit, where we
find the words "jatu," meaning "pitch," and "jatu-krit," meaning
"pitch creating," "pitch producing" (referring to coniferous or res-
inous trees). The Latin equivalent is claimed by some to be origi-
nally "gwitu-men" (pertaining to pitch), and by others, "pixtumens"
(exuding or bubbling pitch), which was subsequently shortened to
"bitumen," thence passing via French into English. From the same
root is derived the Anglo Saxon word "cwidu" (Mastix), the
German word "Kitt" (cement or mastic) and the old Norse word
"kvada."

2 HISTORICAL REVIEW I

The following terms have been traced throughout the various
ancient languages:

Sumerian:

Esir (petroleum and native asphalt) ; esir-lah (hard, glossy
asphalt) i ; esir-harsag (rock asphalt) ; esir-e-a (mastic asphalt) ; se-
li-ud (pine tar) ; kunin or esir-ud-du-a (pitch).

Sanskrit:

Jatu (native asphalt also pitch) ; sila-jatu or asmajatam-jatu
(rock asphalt).

Assyrian and Accadian:

Iddu, ittu, it-tu-u, or amaru (native asphalt) ; kukru or kir-kir-
anu (pine tar) ; sippatu or kupru or ku-pur (pitch). In Babylonia,
pitch is still termed "kupru."

Hebrew :

Zephet or hemar (native asphalt) ; zephet or kopher or kofer
(pitch). In Exodus (II, 3) we find the words "hemar" and
"zephet" denoting pitch.

Arabic and Turkish:

Seyali or zift or zipht (native asphalt) ; chemal or humar (hou-
mar) or gasat (qasat) (rock asphalt) ; ghir or gir or kir or kafr
(mastic asphalt) ; zipht or kir or kafr (pitch) ; neftgil (mineral
wax).

Greek:

Maltha (soft asphalt) ; asphaltos (native asphalt) ; pissasphal-
tos or pittasphaltos or pittolium (rock asphalt) ; pissa-hygra or
pisselaion (pine tar) ; pissa or pitta (pitch) ; ampelitis (mineral
wax and asphaltites) ; spinos (bituminous coal) ; anthrax (anthra-
cite coal).

La tin :

Maltha or bitumen liquidum (soft asphalt); bitumen (native
asphalt) ; pixliquida or serum picis (pine tar) ; pix (pitch) ; gagates
(asphaltite and jet and lignite) ; lapis thracius (bituminous coal) ;
carbo (anthracite coal).

Fossils Preserved by Means of Asphalt. One of the most in-
teresting cases on record is in connection with the fossilized remains
of plants and animals recovered from the Rancho-la-Brea asphalt
pits in Los Angeles County, California, about eight miles from the
City of Los Angeles. 1 These consist of a series of crater-like pits,

I FOSSILS PRESERVED BY MEANS OF ASPHALT 3

generally disconnected, now filled with asphalt, from which a variety
of prehistoric flora and fauna have been excavated, including the
trunks of trees, pine cones, acorns, mastodons, woolly mammoths,
elephants, the ancient ox, giant sloth, camel, saber-toothed tiger,
lion, horse, wolf, cave bear, and numerous species of vultures and

w . '.i

Courtesy i-/os /\ngcies museum.

FIG. 2. Cypress Tree Preserved by Asphalt for 25,000 Years, Rancho-Ia-Brea Asphalt

Pits, California.

carnivorous birds, all now extinct. The theory has been advanced
that the pits were originally formed by "blow-outs'* of gas from an
underlying oil deposit, forming surface craters of funnel-like shape,
filled by an inflow of soft, sticky asphalt, which in time became
quiescent, possibly crusting over, but deadly to any form of beast

HISTORICAL REVIEW

that stepped into them. Once mired in the asphalt, the victim's
struggles would only sink it deeper and attract a host of carnivores
to the feast. These in turn would only contribute so many more
victims to the insatiable greed of the trap. Then came carrion
eaters, vultures, eagles and many others, which contributed avian

Courtesy Los Angeles Museum.

FIG. 3. Bones of Pre-historic Animals Excavated from Rancho-la-Brea Asphalt Pits.

remains to the mass. An artist's conception of the "Death Trap"
of Rancho-la-Brea is illustrated in Fig. i. The skeletons have been
preserved perfectly by the asphalt. They have been identified by
archeologists as belonging to the pleistocene or glacial period, which
according to authorities terminated about 25,000 years ago, or
long before the advent of man.

I USE OF ASPHALT BY THE SUMER1ANS 5

Figure 2 shows the trunk of a pleistocene cypress found in one
of the pits in an upright position, packed solidly about with bones
of the aforementioned animals, and preserved in almost its original
state by the asphalt which surrounded it. This represents one of
the oldest specimens of wood in existence and bears mute evidence
of the remarkable preservation properties of asphalt.

Figure 3 shows a mass of prehistoric elephant bones, as they were
being excavated from the asphalt in an adjacent pit. In no other
known mineral deposits are the bones of these huge beasts preserved
as well as in the asphalt beds of Rancho-la-Brea. A smaller deposit
of a similar character has been found near McKittrick, Cal. 2

Use of Asphalt by the Sumerians (about 3800 to 2500 B.C.)- 3
The earliest recorded use of asphalt by the human race was by the
pre-Babylonian inhabitants of the Euphrates Valley in southeastern
Mesopotamia, the present Iraq, formerly called Sumer and Accad
(Akkad), and later Babylonia. In this region, between the river
Nile in Egypt and the Indus river in India, there occur various de-
posits of asphalt as illustrated in Fig. 4. The following historical
data have been recorded:

King Sargon of Accad (about 3800 B.C.}. A legend has come
down through the ages that King Sargon, while an infant, was
placed in a reed basket coated with asphalt, by his mother Itti-Bel, a
Priestess, and set adrift on the waters of the Euphrates river during
one of its frequent overflows. 4 This corresponds closely with the
tale of Moses, later appearing in the Bible.

Manishtusu, King of Kish (about 3600 B.C.}. The bust of
this early Sumerian ruler was found in the course of excavations
at Susa, in Persia, whence it is supposed to have been carried by an
Elamite conqueror in the twelfth century B.C. 5 In describing this
statue, M. J. de Morgan states ; "the eyes, composed of white lime-
stone, once ornamented with black pupils now fallen off, are held in
their orbits with the aid of bitumen 9 , the face appears rough; the
beard and hair are of conventional design; as regards the inscrip-
tion, it is engraved in lineal cuneiform characters of the most ancient
style." The original is at the Louvre and is illustrated in Fig. 5.

Ornaments (about 3500 B.C.}. Fragments of a ring com-
posed of asphalt have been unearthed above the flood layer of the
Euphrates at the site of the prehistoric city of Ur in southern Baby-

HISTORICAL REVIEW

FIG. 4. Asphalt Deposits between Nile and Indus Rivers.

I USE OF ASPHALT BY THE SUM BRIANS 7

Ionia, ascribed to the Sumerians of about 3500 B.C. 6 Upon analy-
sis it was found to consist of the following:

Soluble in pyridine 63.7 per cent

Ash recovered from pyridine extract 3.8 per cent

Ash not removed by pyridine 27.4 per cent

CO 2 equivalent to CaO in ash 1.9 per cent

Organic matter (by difference) 3.2 per cent

Total 100.0 per cent

The mineral constituents were composed of 5 i per cent silica (sand,
diatoms, foraminifera and cells) and 34 per cent CaSO 4 .

From "The Civilization of Babylonia and Assyria," J. B. Lippincott Co.
FIG. 5. Bust of Manishtusu, King of Kish (3600 B.C.) with Eyes Set in Asphalt.

An interesting ornament has been excavated from one of the
graves of a Sumerian King at Ur 7 consisting of a statue of a ram

HISTORICAL REVIEW

dating back to 3500-3100 B.C. as illustrated in Fig. 6. The head
and legs of the ram, also the tree-trunk are carved out of wood over
which gold foil has been cemented by means of asphalt. The back
$nd flanks of the ram are coated with asphalt in which hair has been
embedded.

At Tell-Asmar in Eshnunna (3200 to 2900 B.C.). Excavations

(From F. A. Brockman, Leipzig. Courtesy
of New York Public Library)

FIG. 6. Sumerian Statue of a Ram (3500-3100 B.C.)

in 1931 at Tell-Asmar, 50 miles northeast of Baghdad, on the
eastern bank of Diyala river (which joins the Tigris river directly
south of Baghdad) have revealed the use of asphaltic mastic by the
Sumerians for building purposes. 8 Similarly, at Khafaje, in the
same vicinity, excavations have uncovered floors composed of a layer
of asphalt mastic 3 to 6 cms. thick, likewise clay bricks bonded
together with asphalt mastic. This mastic has been identified as

USE OF ASPHALT BY THE SUMERIANS

asphalt (probably originating in the vicinity of Hit), mineral filler
(loam, limestone and marl) and vegetable fibers (straw). This

FIG. 7. Babylonian Pavements Excavated at Tell-Asmar.

FIG. 8. Babylonian Stair Treads at
Tell-Asmar.

FIG. 9. Babylonian Baths Waterproofed
with Asphalt-Mastic at Tell-Asmar.

composition was used for bonding bricks in the construction of
buildings and pavements (Fig. 7) ; for protecting exterior masonry
surfaces; for troweling over the surface of interior floors and

HISTORICAL REVIEW

stair treads (Fig. 8); and for waterproofing baths (Fig. 9),
drains, etc.

Lugal-daudu, King of Adab (about 3000 B.C.). In 1903-4,
Dr. E. J. Banks, while excavating at Adab (known also as Bismaya,
between the EuhctifiOJldJDuH^^ a marble statue

of and J* Co*

FIG. 10. Statue of Lugal-daudu, King of Adab (3000 B.C.) Showing Eyesockets Lined

with Asphalt.

of Lugal-daudu, King of Adab (Fig. 10), one of the early Sumer-
ian rulers, who lived about 3000 B.C. 10 An inscription reveals
the name of the city of Adab. The eyesockets are hollow, and
still show the presence of asphalt, indicating that they were
once inlaid with some substance, probably ivory or mother-of-
pearl. The statue is now on exhibition at the Ottoman Museum
in Istanbul. 11

USE OF ASPHALT BY THE SUMERIANS

Another statue (Fig. n) originating about the same time (3000
B.C.), known as the "Human-Headed Bull," is composed of black
steatite, inlaid with small yellow shells imitating streaks, and held in
place with asphalt. Many of the shells are intact, gripped firmly by
the asphalt throughout fifty centuries of time and exposure, thus
furnishing evidence of its remarkable adhesiveness and durability.
This statue is now at the Louvre, Paris. 12

From "The Civilization of Babylonia and Assyria," J. B. Ltppincott Co.
FIG. ii. Human-Headed Bull (3000 B.C.) with Shells Inlaid in Asphalt.

Entemena of Shirpula (about 2850 B.C.). An interesting spec-
imen of Sumerian art was excavated at Lagash, near the mouth of
the Euphrates, consisting of a sculptured votive offering dating back
to Entemena, ruler or so-called "Patesi" of Shirpula (2850 B.C.),
This bears as an inscription, the heraldic device of Lagash, by
means of which we are enabled to fix its date and origin. The tablet

HISTORICAL REVIEW

is an artificial composition of clay and asphalt (Fig. 12). It is also
on exhibition at the Louvre. 13

Ur-Nind, King of Lagash (about 2800 B.C.). In the city of
Kish (Persia) there has been excavated the palace of King Ur-Nina,
the foundations of which consist of plano-convex bricks cemented
together with asphalt mortar. Similarly, in the ancient city of Nip-
pur (about 60 miles south of Baghdad) excavations show Sumer-
ian structures dating from this same period, composed of natural

From "The Civilization of Babylonia and Assyria," J. B. Lippincott Co.
FIG. 12. Heraldic Device of Lagash (2850 B.C.) Cast in Asphalt.

stones joined together with asphalt mortar, including the "ziggurat"
of Enlil.

Ornaments and Sculptured Objects (2800 to 2500 B.C.).
A number of specimens of sculpture involving the use of asphalt
were excavated at Susa in the province of Susiana, by M. J. de
Morgan's expedition of Paris. 14 These are in an excellent state
of preservation, and by the inscriptions and characteristic orna-

USE OF ASPHALT BY THE SUMERIANS

mentation are supposed to have originated between 2800 and
2500 B.C.

Figure 13 shows various small animals carved of alabaster
having the eyes cemented in place with asphalt; Fig. 14, two decor-
ated vases composed wholly of asphalt; and Fig. 15, a sculpture

From "Memoires de la Delegation en Perse," by Edm. Pettier.
FIG. 13. Sumerian Sculpture with Eyes Set in Asphalt.

of an animal in primitive form, hewn from a mass of asphalt. The
French chemist, Henri Le Chatelier, analyzed some of the jtsphalt,
and found it to consist of the fol-
lowing: 15

Moisture, 2.8 per cent; asphalt,
24.4 per cent; wax, 1.6 per cent;
mineral matter, 71.2 per cent. The
mineral matter was composed of:
calcium carbonate, 45.2 per cent;
calcium sulfate, 3.5 per cent; cal-
cium phosphate, 0.8 per cent; iron,
aluminium and silicon oxides, 21.7
per cent.

This is conclusive proof that
the asphalt is a natural product

composed of 25 per cent asphalt and 75 per cent mineral matter,
similar to the material obtained in the locality at the present

day.

Small statues of Sumerian origin (about 2500 B.C.) have been
unearthed in Mesopotamia, composed of white clay with wigs of
asphalt and blobs of red paint on the cheeks. 16

Gudea of Lagash (about 2700 B.C.) . Another relic, known as
the "Libation Vase" (Fig. 16) is composed of green steatite, carved

From "Memoires de la Delegation
en Perse," by Edm. Pettier.

p IG .

4 . Persian Vases Hewn from
Blocks of Asphalt.

HISTORICAL REVIEW

in the form of strange mythical monsters, the effect of which is
heightened by incrusted little shells set in asphalt, to represent the

From "Memoires de la Delegation en Perse," by Edm. Pettier.
FlG. 15. Primitive Animal Carved from Asphalt.

scaly backs of winged serpents. The serpent was supposed to rep-
resent the emblem of the god Ningish-
zida, to whom the accompanying inscrip-
tion shows the vase to be dedicated by
Gudea, ruler of Patesi of Lagash. This
is considered one of the best specimens
of Sumerian sculpture, and represents
the height of Sumerian art. It is also
at the Louvre. 17

Another inscription credited to Gu-
dea states: 18

From "The Civilization of Babylonia

and Assyria," J. B. Lippincott Co. a* t i, r A.I_ TV /T J

Asphalt from the Magda moun-

Fiai6 Libation Vase Dedicated ta } ns j n lam wag transported to his

to Gudea, Ruler of Lagash (2700 ^. / T , ,, r

B.C.), Showing Shells Set In As- <~lty Ot JLagash,
phalt.

Tablets of Gilgamish (about 2500

B.C.). In the epic of Gilgamish as revealed in the twelve inscribed
stone tablets collected by Assur-bani-pal, king of Assyria (668-626
B.C.), we find reference to the use of asphalt for building purposes.
These tablets date back to about 2500 B.C. and constitute one of the
most important pre-Babylonian literary records. In the eleventh
tablet, Ut-Napishtim relates the w T ell-known story of the Babylonian
flood, stating that he u smeared the inside of a boat with six sar
(measures) of kupru (asphalt) and the outside with three sar.

M19

I USE OF ASPHALT BY PREHISTORIC RACES IN INDIA 15

The Persian writer al-Kazwini 20 gives the following interesting
information relative to the collection and treatment of asphalt found
in ancient Persia :

"There are two kinds of native asphalt. First the kind that
oozes from certain mountains; second we have the kind that appears
with water in certain pools. When boiled with the water and as
long as they remain together, the asphalt is soft; but if we separate
them, the asphalt hardens and becomes hard and dry. It is col-
lected by means of matting and deposited on the shore. Then it is
placed in a kettle under which a fire has been lit, and a certain
amount of sand is added and a mix prepared by constant stirring.
When the mix is ready, it is poured on the ground, where it cools
and hardens."

In ancient texts we are informed that asphalt mastic was always
sold by volume, namely, by the so-called "gur," the measure used
for grain, beer, etc., as is evidenced by the very name Ur. Crude
asphalt, on the other hand, was always sold by weight, by the
"mina" or "shekel," as were metals and other solid commodities.

Bur-Sin, King of Ur (about 2500 B.C.) An ancient Sumerian
chapel erected to the Moon God "Nin-Gal" has recently been
excavated, in which the floors are composed of burnt bricks em-
bedded in asphalt mastic which still shows impressions of reeds with
which it must originally have been mixed, adorned with stone
tablets, each of which bears the following inscription:

"Bur-Sin, King of Ur, of Sumer and Accad, King of the four
portions of the World, has constructed this for his Master Nin-Gal"

Use of Asphalt by Pre-historic Races in India (about 3000
B.C.). At excavations conducted in 1923 at Mohenjo-Daro,
Harappa and Nal, in the Indus valley, northwestern India, evi-
dences of an advanced form of civilization have been revealed. 21
An asphalt mastic, composed of a mixture of asphalt, clay, gypsum
and organic matter, was introduced between two brick walls in a
layer about i-in. thick for waterproofing purposes. A bathing pool
measuring 39 by 23 by 8 feet in depth has been unearthed, located
in front of an ancient temple, probably for ritualistic cleansing pur-
poses, containing a layer of the mastic on the outside of its walls and
beneath its floor, 22 as illustrated in Figs. 17 and 18.

HISTORICAL REVIEW

The mastic was found to have the following composition:

Organic constituents 28.3 per cent

Mineral constituents 71.7 per cent

Total 100.0 per cent

The organic constituents were 29.3% soluble in carbon disul-.
fide and 85.5% in pyridine, and contained 7.1% sulfur. The
mineral constituents contained: SiO 2 and insoluble: 55.1%; Fe 2 O 3
and A1 2 O 3 : 11.296; CaSO*: 13.7^; CaO: 4.896; MgCO 3 : 4.296;

Photo Archeol. Survey of India
FIG. 17. Water Tank in Front of a Temple Excavated at Mohenjo Daro (Indus Valley).

vanadium and nickel: traces. This mastic was also used for
mosaic and inlaid work, as an adhesive for the application of orna-
ments to statues, and as a protective coating for woodwork. Seep-
ages of liquid asphalt, as well as rock asphalt deposits exist today
in India, on the Basti river, near Isakhel (Kashmir) and in the
Sierras in Hazara District.

Use of Asphalt by the Early Egyptians (2500 to 1500 B.C.). 23
The ancient Egyptians were the first to adopt the practice of em-

USE OF ASPHALT BY THE EARLY EGYPTIANS

balmlng their dead rulers and wrapping the bodies in cloth which
was coated with liquid, or melted, solid waterproofing substances,
including balsams, oleb-resins, gum-resins, true resins, wood-tar
pitch (obtained during the process of charcoal making), and fre-
quently with natural asphalt, although Alfred Lucas, formerly di-
rector of the Chemical Department of Egypt, has recently con-
tended that he has been unable to detect asphalt in the black
substance covering embalmed mummies, and concludes that resin

Photo Archeol. Survey of India
FIG. 18. Wall of Water Tank at Mohenjo Daro, Showing the Bituminous Layer.

employed for this purpose. Strabo 24 informs us that "the
Egyptians used the Dead Sea asphalt for embalming their dead,"
and this practice is also alluded to by Diodorus Siculus, Pliny the
Elder, Dioscorides, and other writers (loc. cit). The preserved
remains are known as "mummies" (Fig. 19).

Before 1000 or 900 B.C. asphalt was rarely used in mummifi-
cation, except to coat the cloth wrappings and thereby protect the
body from the elements. After the viscera had been removed, the
cavities were filled with a mixture of resins and spices, the corpse

HISTORICAL REVIEW

immersed in a bath of potash or soda, dried, and finally wrapped
From 500 to about 40 B.C. (i.e. in Roman times), asphalt was
generally used both to fill the corpse cavities, as well as to coat the
cloth wrappings. 25 The word u mumia" first made its appearance
in Arabian and Byzantine literature about 1000 A.D., 26 signifying
"bitumen." In Persian it acquired the meaning "paraffin wax,"
and in Syriac alluded to "substances used for mummification."

The product "mumia" was used in prescriptions, as early as the
1 2th century, by the famous Arabian physician Al Magor, for the

FIG. 19. Mummy Preserved with Asphalt

treatment of contusions and wounds. Its production soon became
a special industry in the hands of the Alexandrian Jews. As the
supply of mummies was of course limited, other expedients came
into vogue. The corpses of slaves or criminals were filled with
asphalt, swathed and artificially aged in the sun. This deception
continued for several centuries until in 1564 A.D., it was exposed
after a journey into Egypt by the French physician, Guy de la Fon-
taine, and as a result, this trade became extinct in the iyth century.
The earliest mummies in existence concerning which we have
authentic data, date back to the Sixth Egyptian Dynasty (about
2500 B.C.). The earliest specimens include the mummy of Seker-

I USE OF ASPHALT IN BIBLICAL TIMES 19

em-sa-f, unearthed at Sakkarah in 1881, and exhibited at Giza,
near Cairo, 27 and the mummy of King Merenre, now at the Boulak
Museum, Cairo. 28

Tut-ankh-amen (or Tutenkhamun), the boy Pharaoh, who ruled
Egypt about 2000 B.C. and whose treasure-filled tomb was discov-
ered by Lord Carnarvon of England in 1923, contained two statues
of the Pharaoh, a black box, a figure of a swan, a couch, an ancient
chariot, and numerous other wooden objects preserved by impreg-
nation with asphalt.

Use of Asphalt in Biblical Times (2500 to 1500 B.C.). 29 Some
contend that Noah used asphalt in the construction of the Ark
(Genesis VI, 4). The Biblical text reads, that it was treated with
"pitch" within and without: "bituminabis earn bituminae" (Vul-
gate). There is little doubt but that asphalt was used for this
purpose, since it is well known that canoes and dugouts in the early
days were made water-tight in the same way. In fact, a number
of primitive tribes to-day adopt the same procedure. If asphalt
was actually used by Noah, the date would be fixed at approximately
2500 B.C., which is usually assigned to the Deluge.

We find numerous other references in the scriptures to sub-
stances corresponding to what we now know to be asphalt. The
Book of Genesis (XI, 3) in describing the building of the Tower of
Babel (about 2000 B.C.) states ". . . and they had brick for stone,
and slime had they for mortar." There seems to be no question
but that the so-called "slime" alludes to asphalt, since the word
translated as "slime" in the English version (1568), occurs as
d<r<aXros in the Septuagint, and as "bitumen" in the Vulgate.

In the Septuagint, or Greek version of the Bible, this word is
translated as "asphaltos," and in the Vulgate or Latin version, as
"bitumen." In the Bishop's Bible of 1568 and in subsequent trans-
lations into English, the word is given as "slime." In the Douay
translation of 1600, it is "bitume," while in Luther's German ver-
sion, it appears as "Thon," the German word for clay.

Similarly, in Genesis (XIV, 10) we are informed that the Vale
of Siddim "was full of 5/m^pits," referring no doubt to exudations
of liquid asphalt. Moreover, it is pointed out by certain authorities
that the area described as the Vale of Siddim corresponds to our
present Dead Sea, from which asphalt is still obtained.

HISTORICAL REVIEW

Again we are told (Exodus II, 3) that in constructing the basket
of bulrushes in which Moses was placed, it was daubed "with slime
and with pitch" This took place about 1500 B.C. 30 As was pointed
out previously, this constituted an early method of constructing
boats. Even at the present time, boats known as "guffas" as illus-
trated in Fig. 20 are constructed of woven reeds caulked with as-

FIG. 20. The Guffa, or Coracle, Used for Centuries in Parts of the Near East.

phalt, 31 and are used to ferry passengers and merchandise across
the Tigris river at Baghdad.

While excavating at the ancient Biblical city of Jericho in Pales-
tine, 32 brick walls were found in which asphalt mastic was used as
mortar, dating back to about 2500-2100 B.C.

It is also contended that the glance pitch deposit known as u Suk-
El-Chan," on the western slope of Mount Hermon in the upper
Jordan valley, near Hasbaya (loc. cit.) has been worked since about
1600 B.C.

Use of Asphalt by the Babylonians (2500 to 538 B.C.). Baby-
Ionia was the name given to the plain of the Tigris and Euphrates

I USE OF ASPHALT BY THE BABYLONIANS 21

rivers, now forming the modern province of Irak. The Babylonians
were well versed in the art of building, and each monarch commemo-
rated his reign and perpetuated his name by constructing some vast
engineering work. Certain kings built roadways, others built re-
taining walls to impound the waters of the Euphrates, and still others
mighty battlements and palaces. Such facts were indelibly recorded
by inscriptions on the bricks used for the purpose, many of which
are still in existence. The bricks were of the so-called "plano-
convex" type, being formed by hand, with one side flat and the
other face convex and then kiln burnt. Bitumen was used as mor-
tar from very early times. Sand, gravel or clay were employed in
preparing these mastics. Due to the porous nature of the bricks,
the asphalt was partially absorbed, resulting in a very strong bond.
At first, the spaces between the bricks was filled with a 3 to 6 cm.
layer of mastic, but in later periods there was a tendency to dimin-
ish the space.

Asphalt-coated tree trunks, e.g. poplar, were often used to rein-
force wall corners and joints, as for instance in the temple tower of
Ninmach in Babylon. In vaults or arches a mastic-loam composition
was used as mortar for the bricks, and the keystone was usually
dipped in asphalt before being set in place. Reuther reports that
bituminous paint was applied to the outer walls of buildings in
Babylon over a loam plaster, first primed with a gypsum distemper.
Asphalt was also used to waterproof brick basins at Ur and Erech. 83

King Khammurabi (about 2200 B.C.). The use of bitumi-
nous mortar was said to have been introduced in the city of Babylon
by King Khammurabi (Amraphel of the Bible). Robert Koldewey
reports that when excavating in Babylon, he found "it was exceed-
ingly difficult to separate the brick courses from each other." 34
This \vas also confirmed by A. H. Layard, who states that "Bricks
bonded with asphalt have remained immovably in place for thou-
sands of years." 35

Queen S emir amis (about 700 B.C.) Queen Semiramis is
stated to have built a tunnel under the Euphrates at Babylon, about
1000 meters long, of burnt bricks coated with asphalt as mortar. 36
The asphalt thus functioned as a waterproofing agent, very much
in the same manner as it is used to-day.

King Nabopolassar (625 to 604 B.C.). Nabopolassar is cred-

22 HISTORICAL REVIEW I

ited with having built a palace on a platform consisting of ten
courses of burnt bricks set with an asphalt mortar and surfaced
with a layer of asphalt mastic. One of his inscriptions states :

U I made a Nabalu and laid its foundations against the bosom of
the underworld, on the surface of the water, in bitumen and brick.
I raised its roof and connected the terrace with the palace. With
bitumen and brick, I made it tall like unto wooded mountains."

According to his son Nebuchadnezzer, he is given the credit to
have laid the first asphalt block pavement in Babylon.

King Nebuchadnezzar (604 to 561 B.C.). Of all the Baby-
lonian rulers, Nebuchadnezzar was the most progressive, and is
stated to have reconstructed the entire city. The bricks bore in-
scriptions relating to his work, and several refer specifically to the
use of asphalt. One found in the so-called "Procession Street"
(Aiburshabu) which led from his palace to the North wall, reads as
follows : sr

"Nebuchadnezzar, King of Babylon, he who made Esaglia and
Ezida glorious, son of Nabopolassar, King of Babylon. The streets
of Babylon, the Procession Street of Nabu and Marduk, my lords,
which Nabopolassar, King of Babylon, the father who begot me, had
made a road glistening with asphalt and burnt bricks; I, the wise
suppliant who fears their lordships, placed above the bitumen and
burnt bricks, a mighty superstructure of shining dust, made them
strong within with bitumen and burnt bricks as a high-lying road.
Nabu and Marduk, when you traverse these streets in joy, may bene-
fits for me rest upon your lips; life for distant days, and well-being
for the body. Before you I will advance upon them. May I attain
eternal age!"

This street was constructed with stone slabs brought from distant
parts, set in a bituminous mortar, the interstices being very narrow
at the surface and widening towards the base of the stones. The
foundation consisted of three or more courses of bricks joined to-
gether with bituminous mortar.

This would seem to be the forerunner of the present-day pave-
ment composed of stone blocks set in asphalt. It seems strange that
the art should have become lost to mankind, only to be rediscovered
in the nineteenth century A.D.

The most comprehensive relic left by Nebuchadnezzar is known

I USE OF ASPHALT BY THE BABYLONIANS 23

as the "Large Inscribed Stone Tablet" (sometimes referred to as
the "East India House Inscription"), which contains a detailed ac-
count of his building activities. A translation by Fr. Delitsch 38
reads in part as follows (Column 7, lines 34 et seq.) :

"In Babil, my favorite city that I love, was the palace, the house,
the marvel of mankind, the center of the land, the dwelling of
majesty, upon the Babil place in Babil, from Imgur-Bel to the eastern
canal Libil-Higalla ; from the bank of the Euphrates to Aiburshabu,
which Nabopolassar, King of Babylon, my father, my begetter, built
of crude bricks, and dwelt in it In consequence of high waters, its
foundations had become weak, and owing to the filling up of the
streets of Babil, the gateway of that palace had become too low. I
tore down its walls of dried brick, and laid its corner-stone bare, and
reached the depth of the waters. Facing the water, I laid its foun-
dation firmly, and raised it mountain high with bitumen and burnt
brick. Mighty cedars, I caused to be laid down at length for its
roofing. . . . For protection, I built two massive walls of asphalt
and brick, 490 ells beyond Nimitti-Bel. Between them I erected a
structure of bricks on which I built my kingly dwelling of asphalt and
bricks. This I surrounded with a massive wall of asphalt and burnt
bricks, and made upon it a lofty foundation for my royal dwelling
of asphalt and burnt bricks"

It thus appears that Nebuchadnezzar profited by the experience
of his father, and instead of building a retaining wall of dried clay
bricks, which had failed to hold back the Euphrates due to its lack
of waterproof properties, he resorted to the use of burnt bricks and
asphalt, and apparently with satisfactory results.

Robert Koldewey's investigations indicate that the method of
constructing walls in Babylonia and Nineveh consisted in laying in
rotation, first a course of bricks, then a layer of asphalt, then a layer
of clay and then another course of bricks. 39 The joints in each
course were composed of asphalt and clay. In every fifth course, the
clay was replaced by a matting of reeds. This matting is now en-
tirely rotted and gone, but its impression is clearly recognizable in
the asphalt. An attempt to separate the courses to prevent adhesion
is thus apparent, but the reason is not obvious. Only in one locality
(Temple of Borsippa) does it appear that asphalt has been used in
direct contact with the bricks, where they still hold together in a
firm mass.

HISTORICAL REVIEW

It is probable that the asphalt used by the Babylonians was de-
rived from springs similar to the ones still found in Mesopotamia,
of which Fig. 21 is a typical example of an asphalt spring at Hit.
Deposits of pure asphalt are found to-day at various localities in
this region, including Ain Mamurah, Ain-el-Maraj, Al-Kuwait
(Arabia), Bushire (Iran), and Bundar Abbas (Iran).

Figure 22 shows the present appearance of the brick floor of
Nebuchadnezzar's Throne Hall, Babylon, looking towards the

From "Light on the Old Testament," by Prof. A. T. Clay.
FIG. 21. Asphalt Spring in Mesopotamia.

Euphrates. The burnt bricks bearing the name of Nebuchadnezzar
(of which one is shown in the foreground) were laid in asphalt, and
are still so firmly jointed together to-day, that it is impossible to
part them without destroying their integrity. 40

King Nebuchadnezzar also built a bridge across the Euphrates
near Babylon, 370 feet long. The piers were constructed of burnt
bricks embedded in asphalt mastic, the bases of which were pro-
tected with a superficial coating of asphalt. He also constructed
large sewers ("cloacae") for draining the city of Babylon, lined
with blocks composed of a mixture of asphalt, loam and gravel.

USE OF ASPHALT BY THE ASSYRIANS

The use of bituminous mortar was abandoned in Babylon
towards the end of Nebuchadnezzar's reign, in favor of lime mor-
tar to which varying amounts of asphalt were added. After the
fall of Babylon (538 B.C.) even the addition of asphalt was dis-
continued. In the ensuing Persian period (538 to 300 B.C.), the

FIG. 22. Floor of Nebuchadnezzar's Temple as it Appears To-day, Showing Blocks

Joined by Means of Asphalt.

lime was replaced in turn w r ith clay as mortar, and this resulted in a
retrogression in the building art.

Use of Asphalt by the Assyrians (1400 to 607 B.C.). 41 The
name Assyria was derived from the city of Assur (now Kalah
Shargat) situated on the right bank of the Tigris, midway between
the Greater and Lesser Zab rivers. Assur was finally supplanted

26 HISTORICAL REVIEW I

by Nineveh as capital (Nebi Yanus and Kuyunjik) some 60 miles
farther north.

King Adad-Nirari I (about 1300 B.C.). This monarch is stated
to have built an embankment i mile long along the banks of the
Tigris, in which the stones were joined together with an asphaltic
mortar. W. Andrae reports that tablets have been found in the
embankment at Assur, recording the fact that the asphalt ("kupru" :
pitch) used was mined at Ubase (present Quala Shargat), and in
reference to the mortar states that "After 3300 years, it still faith-
fully fulfils its purpose." 42 Andrae likewise refers to an ancient
temple mound excavated at the former site of Erech, dating back
to this same period, which was constructed of courses of dried clay
bricks bound together with a mortar composed of asphalt mixed
with clay. It is interesting to note in passing, that in the ancient
Assyrian moral code we find reference to asphalt, which was pre-
scribed to be poured onto the heads of delinquents in a molten
state.

King Tukulti-Ninurta 11 (890 to 884 B.C.). This King, in his
annals makes reference to the fact: 43

"In front of Hit, by the bitumen springs the place of Usmeta
Stones where the gods speak I spent the night."

King Sargon (722 to 705 B.C.). The following inscription oc-
curs on the bricks of the so-called "Sargon Wall" of Babylon, built
by King Sargon, founder of the last and most illustrious Assyrian
dynasty, as it has been translated by Fr. Delitsch : 44

"To Marduk, the Great Lord, the divine Creator, who inhabits
Esagila, the Lord of Babil, his lord Sargon, the mighty king, King
of the land of Assur, King of all, governor of Babil, King of Sumer
and Akkad, the nourisher of Esagila and Ezida. To build Imurg-
Bel was his desire; he caused burnt brick of pure JKiru (?) to be
struck, built a kar ( ?) with tar and asphalt on the side of the Ishtar
Gate to the bank of the Euphrates in the depth of the water, and
founded Imgur-Bel and Nimitti-Bel mountain high, firm upon it.
This work may Marduk, the great Lord, graciously behold, and
grant Sargon, the prince who cherishes him, life! Like the foun-
dation stone of the Sacred City, may the years of his reign endure. "

"Imgur-Bel" was the name given to the inner wall of Babylon,
and "Nimitti-Ber to the outer. ^

I REFERENCES BY GREEK AND ROMAN WRITERS 27

King Sennacherib (704 to 682 B.C.). One of this King's in-
scriptions 45 informs us that he :

"Covered the bed of the diverted river Telbiti with rush matting
at the bottom and quarried stone on top, cemented together with
natural pitch (asphalt). I thus had a stretch of land 454 ells long
and 289 ells wide, raised out of the water and changed into dry
land" (Inscription No. 6).

The year 607 B.C. marked the destruction of Nineveh and the
end of the Assyrian empire.

Use of Asphalt in Constructing Lake-Dwellings (about 1000
B.C.). In the bronze-age, dwellings were constructed on piles in
lakes close to the shore the better to protect the inhabitants from
the ravages of wild animals and attacks from marauders. Excava-
tions have shown that the wooden piles were preserved from decay
by coating with asphalt. Remains preserved in this manner have
been found in Switzerland, in the lakes of Bourget, Geneva, N^u-
chatel, Bienne, Zurich and Constance. 46

References to Bituminous Substances by Greek and Roman
Writers (500 B.C. to 817 A.D.)

Herodotus (484 to 425 B.C.). The Greek historian Herodo-
tus, in his treatise "Historiarum" 47 refers to deposits of asphalt at
Hit (the present town of Kirkuk in Mesopotamia) as follows:

"There is a city called Is (Hit), eight days' journey from Baby-
lon, where a little river flows, also named Is, a tributary stream of
the river Euphrates. From the source of this river many 'gouts'
of asphalt rise with the water; and from thence the asphalt is
brought for the walls of Babylon."

Many references occur in the earliest writings to Hit (Accadian
"Id," Greek "Is"). A more recent though interesting description
of the asphalt deposit at Hit is furnished by a British traveler
George Rawlinson ( I745), 48 who described his visit to that locality
as follows:

"Having spent three days or better among the ruins of old
Babylon, we came into a town called Hit, inhabited only by Arabians,
but very ruinous. Near unto this town is a valley of pitch, very
marvelous to behold, and a thing almost incredible, wherein are
many springs throwing out abundantly a kind of black substance,

28 HISTORICAL REVIEW I

like unto tar and pitch, which serveth all the countries thereabouts
to make staunch their barks and boats. Every one of which springs
maketh a noise like a smith's forge in puffing out the matter, which
never ceaseth night or day, and the noise is heard a mile off, swal-
lowing all the weighty things that come upon it. The Moors call it
the Mouth of Hell."

A translation of a tablet unearthed at Karnak 49 reveals the
fact that part of the tribute paid Thothmes III (Tethmosis III),
about 1500 B.C. from Mesopotamian cities consisted of 2040 minae
(about 1000 kg.) of "zift" (Arabic for native asphalt), sent by
the ruler of Is (Hit), 50 but the foregoing has been controverted.

Herodotus also states (VI, 119) that asphalt was obtained
from wells near Ardericca (near the present town of Kirab) in the
land of Cissia (now Persia) :

"At Ardericca, 210 stadia from Susa, there is a well another
40 stadia away, which produces three different substances, since
asphalt, salt and oil are drawn up from it. ... It assumes three
different forms : the asphalt and the salt immediately become solid,
but the oil they collect, and the Persians call it Rhadinance; it is
black and emits a strong odor."

At Elam, in the province of Susiana in Persia, asphalt is still
collected in this crude manner.

Herodotus refers (IV, 195) to a deposit of pure, soft asphalt
at Zacynthus (now Zante), on the Greek coast, as follows:

"I myself have seen the pitch drawn up out a pool of water in
Zacynthus, and there are several pools there, the largest of which
is 70 orgyoe (i- e - fathoms) long and broad, and 2 orgyoe in depth.
Into this, they let down a pole with a myrtle branch fastened to its
end, and then draw up the pitch adhering to the myrtle. It has the
smell of asphalt, but in other respects is better than the pitch of
Pieria (now Thessalonica). Then they pour it into a pit that has
been dug near the pool; and when much is collected, they fill their
vessels from the pit."

Herodotus was the first writer to describe the construction of
small round boats woven together of reeds, like baskets, covered on
the outside with hides, and waterproofed with a coating of natural
asphalt, similar to the present-day "guffas" found in Mesopotamia
(I, 194). He also described the use of bituminous mortar, com-

I REFERENCES BY GREEK AND ROMAN WRITERS 29

posed of asphalt and straw, for joining together stones and clay
bricks in building masonry walls at Media.

Thucydides (471 to 401 B.C.). The Greek hsitorian Thu-
cydides 51 refers to the use of petroleum for military purposes and
describes a mixture of asphalt and sulfur, which was used to ignite
fascines piled against the wooden walls in the sieges of Plataea
and Delium.

Hippocrates (460 to 377 B.C.). This Greek philosopher and
physician 52 refers to several of the asphalt deposits already men-
tioned.

Xenophon (430 to 357 B.C.). The Greek historian Xeno-
phon 53 describes a wall built in Media, composed of burnt bricks
cemented together with asphalt, similar to the method of construc-
tion used in Babylon.

Aristotle (384 to 322 B.C.). This Greek writer and philoso-
pher 54 states :

''Inflammable oils rise in large quantities in the soil of Persia,
and in smaller quantities in Sicily, where they often have the distinct
odor of cedar resin. Thick, dark and viscous oils flow beside nat-
ural pitch and asphalt in Macedonia, Thrace and Illyria (Selenitza
in Albania) from the hot, often burning soil, smelling of sulfur and
bitumen, and diffuse stinking, choking and sometimes deadly fumes. "

Theophrastus (372 to 288 B.C.). This Greek writer 55 de-
scribes the production of wood tar, which he states was an estab-
lished industry. He likewise gives a comprehensive account of
several occurrences of asphalt, and refers to:

"An earth in Cilicia (present Turkey-in-Asia ) , which becomes
viscous on heating."

Antigonus (about 311 B.C.). We are informed 66 that Antig-
onus of Macedonia in 311 B.C. sent Hieronymus of Cardia with
an army to capture the asphalt works at the Dead Sea from the
Nabataeans. This deposit seems to have been greatly prized.
Later, Ptolemy II (309-246 B.C.) in turn, captured the Dead Sea
asphalt works. It then passed on to the Seleucids, from whom
Antony took it and presented it to Cleopatra. The latter leased it
to Malchus, the Nabataean, in 36 B.C., who in 32-31 B.C. failed to

30 HISTORICAL REVIEW I

pay rent and was accordingly punished by Herod. The subsequent
history of this most interesting deposit is lost in obscurity.

Hannibal (247 to 183 B.C.). The Carthaginian general Han-
nibal is said to have used asphalt in compounding the so-called Greek
Fire ( u lgnae Vestoe"), which was claimed to burn so fiercely, that
even water would not extinguish it, and was used extensively by him
in warfare.

Vergil (70 to 19 B.C.). This Roman poet 57 refers to the me-
dicinal use of bitumen, applied externally as a cure for scabies.

Strabo (63 B.C. to 24 A.D.}. The Greek geographer Strabo 58
refers in detail to the Dead Sea asphalt deposit This was termed
u Lacus Asphaltites" by the classical writers, and the asphalt derived
therefrom, as "Bitumen Judaicum." Strabo states (XVI, 740) :

"The Dead Sea is full of asphalt. It comes to the surface ir-
regularly at the center, with noisy disturbance of the water, which
appears as though it were boiling. The visible portion of the
asphalt lumps is round and has the form of a hillock. Much sooty
matter accompanies the gaseous emanation, which tarnishes copper,
silver and all bright metals, and even causes gold to rust."

He adds further (XVI, 764) :

"The asphalt remains on the surface of the water, owing to its
salty nature. People go in rafts to the asphalt, hack it to pieces,
and take as much of it away with them as they can."

He also offers the following interesting theory regarding the
origin and formation of Dead Sea asphalt (XVI, 763) :

"Asphalt is a lumpy earth, which has been liquefied by heat and
again comes forth and spreads out, and eventually becomes con-
verted into a dense, solid mass by the cold sea water, so that it
must be worked with knives and axes. Undoubtedly, this occurs in
the center of the lake, since the fire originates there and likewise
the asphalt. The asphalt is generated irregularly, since the move-
ment of the fire, the force of the wind, etc., have no marked regu-
larity."

Strabo has the following to offer regarding Babylonian asphalt
(I, 16):

"Poseidonius (died 51 B.C.) declares that there are wells of
black and also white naphtha in Babylonia. The white naphtha,

I REFERENCES BY GREEK AND ROMAN WRITERS 31

which attracts fire, is composed of liquid sulfur (?); the black
naphtha is simply liquid black asphalt, which can be burnt in lamps
instead of olive oil."

He states further (XVI, 743):

'There is much asphalt in Babylonia, about which Erathosthenes
(of Alexandria, 276 to 194 B.C.) has the following to say: "The
liquid, which is called naphtha, is found in the region around Susa.
The more solid material, which may become hard, occurs in Baby-
lonia. The source is near the Euphrates. When this river over-
flows its banks, through the melting of the snow on the mountains,
this well also overflows and wends its way to the river. With it
come large lumps of asphalt which is very suitable for use in Cement-
ing bricks for house building. Others say that the liquid kind also
occurs in Babylonia. I have already said how useful the solid kind
is for the building of houses. It is said that ships are also made of
it and that if they are coated with it, they will become watertight'."

Strabo refers (XVI, 738) to the use of asphalt mortar, both
for constructing walls of houses and for waterproofing tunnels. He
observes (VII, 316) :

"Asphalt from Rhodes requires more olive oil for cutting, than
that from Pieria (Thessalonica)."

He informs us that "pissasphaltos" [derived from the Greek
words "pissa" (pix or pitch) and "asphaltos" (asphalt)] 59 occurs
in the neighborhood of Epidamnos (or Dirrachion) on the main-
land of Albania, stating (VII, 316) :

"In the country of the Apolloniates at a place called Nymph-
aeum, there occurs a rock, at the base of which, fire gushes forth,
accompanied by streams of hot water and melted asphalt, and un-
doubtedly it is the mass of asphalt that burns. This occurrence is
found near the summit. The mass carried away by the water is
eventually recovered, since it is again converted into asphalt, which
as Poseidonius has noted, may be dug out of the earth on a hill in
the vicinity."

This most likely alludes to the present-day deposit of Selenitzia
in Albania.

Strabo also refers to the use of asphalt paints, in respect to
which he comments (XVI, 739) :

"For want of wood for building, only the beams and stays in
houses are made of the wood of the date-palm. The stays are stif-

32 HISTORICAL REVIEW I

fener with cord made of plaited rushes. Then everything is plas-
tered and painted and the doors are coated with asphalt."

Diodorus Siculus (about 50 A.D.}. This Greek historian 60
also describes the Dead Sea deposit (XIX, t. 98, Chap. 2) as
follows :

" It is a large sea which yields up much asphalt and from which
a by no means negligible revenue is derived. The sea is about 500
stadia in length and 60 stadia wide. The water stinks and is exceed-
ingly bitter, so that fish cannot live in it, nor do any other creatures
occur in it. Although large rivers of very fresh water flow into it,
the sea remains bitter. Every year a large quantity of asphalt in
pieces more than 3 plethra (no yards) float in the middle of the
sea. The advent of asphalt is heralded 20 days before its arrival,
for all around the sea the stench is wafted by the wind over many
stadia, and all the silver, gold and copper in the neighborhood be-
come tarnished, but the tarnish disappears again when the asphalt
rises to the surface. The district in the vicinity, which is readily
inflammable, and which is pervaded by an unpleasant odor, makes
the people's bodies ill and they die young." 61

In connection with the Babylonian asphalt deposits, he states
(II, Chap. 12):

u Of all the many wonders occurring in Babylonia the most
astounding consists of the large deposits of asphalt which are found
there. So much is found that it not only suffices for many and large
buildings, but the surplus is used by the populace, who gather large
quantities in various localities, which after drying is used as fuel in
place of wood. In spite of the large number of inhabitants who thus
consume the asphalt, its supply remains as inexhaustible as the water
from the wells.

He also alludes to the fact that in constructing the walls of the
city of Media, the stones were cemented together with an asphalt
mortar, as previously remarked by Herodotus and Xenophon. He
refers to the use of asphalt for embalming the dead (XIX, t. 98,
Chap. 2), stating:

"The largest portion of the asphalt derived from the Dead Sea
is exported to Egypt, where among other uses, it is employed to
mummify dead bodies, for without the mixture of this substance
with other aromatics, it would be difficult for them to preserve these
for a long time from the corruption to which they are liable."

I REFERENCES BY GREEK AND ROMAN WRITERS 33

Vitruvms (about 50 A.D.}. The Roman architect Vitruvius,
otherwise known as Marcus Vitruvius Pollio 62 refers to the pres-
ence of asphalt in the neighborhood of Babylon, which he describes
as being of a liquid consistency, and states further (VII, 3 and 8) :

u Asphalt is found in Carthage and Ethiopia, and fluid and solid
varieties are found in Arabia . . . likewise near Joppa in Syria.
... In nomad Arabia are lakes of immense size producing much
bitumen which is gathered by the neighboring tribes. This is not
surprising, because there are many quarries of hard bitumen there.
When a spring of water flows through this land, it draws the bitu-
men with it, and passing along, the water disappears and deposits
the bitumen."

He likewise refers (I, 5 and 8) to the Dead Sea occurrence,
those at the city of Hit, also to the Albanian deposit, and mentions
the use of asphalt mortar for constructing masonry walls at
Media.

Pliny the Elder (23 to 79 A.D.}. This Roman naturalist 63
refers to Dead Sea asphalt (XXXV, 178) as u slimy bitumen" and
states that a deposit is found in solid form "as an earth" in the vi-
cinity of Sidon, which undoubtedly corresponds to the present Suk-
el-Chan glance pitch mine (loc. cit. ). Pliny refers (VI, 99) to
another deposit, most likely in the neighborhood of the present town
of Bushire in Mesopotamia, stating:

"Here flows the river Granis through Susiana, on the right bank
of which the Deximontani dwell, who manipulate bitumen."

Again, he refers (II, 235) to:

"Petroleum wells at Astacensis in Parthia (northeastern Persia)
capable of yielding asphalt."

Pliny describes (XXXV, 178) how the natives of Sicily gather
asphalt, as follows:

"The inhabitants gather the asphalt from the surface of pools,
by stirring with branches, to which it will easily adhere."

He comments (VII, 65 ) upon the high ductility of good asphalt:

"Asphalt that is elastic and cohesive cannot be split apart, since
it adheres to all objects that come in contact with it. It will draw
out into long threads when anything is dipped into the sticky mass,"

34 HISTORICAL REVIEW I

Again (XXXV, 180):

"Bitumen is prized most highly when it is bright and heavy;
and becomes less bright when mixed with pitch. It has the same
properties as sulfur; it cracks, but heals itself, since the cracks again

close up."

* *

He states further that:

"The best quality floats on the surface when the mass is^ boiled
. . . and liquid bitumen is burnt in lamps in place of olive oil"

Pliny alludes to "pissasphaltos" (XXIV, 41; XXXV, 182)' as
follows :

"A mixture of pitch and asphalt being termed pissasphaltos. 1 '

He refers to "ampelitis," i.e. mineral wax (XXXIV, 194))
stating :

"Ampelitis greatly resembles bitumen, and like bitumen becomes
liquid when it has absorbed oil."

He further informs us that "gagates" (asphaltite or jet) are
found in Lycia (XXXVI, 141).

Pliny refers to the production of wood tar (XIV, 122 and 127;
XVI, 38 and 52) as follows:

"Stacking a large pile of wood, covering it with a layer of earth
or sods and then setting fire to the wood. The tar produced in this
manner is drawn off through a drain 16 ells long leading from under
the stack."

He also alludes to the production of wood-tar pitch (XVI, 52)
as follows:

"The boiling of pitch (Latin: 'picem coquere' ) derived from
wood tar."

Likewise, that (XV, 8; XXIV, 24) :

"Tar oil can be obtained by stretching a hide over a cauldron
containing boiling pitch, and then wringing out the condensed liquid."

He refers to the use of wood tar and wood-tar pitch for water-
proofing pottery (XIV, 134; XV, 62), for calking ships (XVI, 56
and 158), and as a paint for roofs and walls (XXXV, 41;
XXXVI, 1 66).

I REFERENCES BY GREEK AND ROMAN WRITERS 35

Pliny refers to the use of asphalt in warfare as follows (CIV) :

u The attack of Lucullus on the city of Samosata was repelled
with the assistance of burning maltha. ... In the city of Samosata
in Commagene, there is a body of water on the surface of which
there was ignited a mass of slime called maltha. When this slime
comes in contact with any solid bodies, it adheres to them and fol-
lows those that retreat Thus as the city was besieged by Lucullus,
the inhabitants ignited the walls and drove back the soldiers and
destroyed their weapons. Experiments have proven that the burn-
ing slime can only be extinguished with damp earth."

He comments (XXXIV, 15) on the use of asphalt as a paint:

"The ancients coated. their bronze monuments wjth bitumen,
which makes it all the more remarkable to remember that they pre-
ferred to cover them with gold. I do not know whether it is a
Roman invention, although it is said that it was done at Rome first."

And again (XXXV, 183):

"Copper house utensils are painted with bitumen to make them
more resistant to heat and flame. . . . Iron workers use it in their
workshops for varnishing iron, for the heads of nails, and for many
other purposes."

He also refers (XIV, 20) to the use of asphalt:

"To coat the inside of wine casks and water receptacles."

Pliny describes the use of asphalt for medicinal purposes
(XXXV, 1 80 and 182) and recommends it for curing boils, inflam-
mation of the eyes, coughs, asthma, blindness, epilepsy, etc. He tells
us that it was sold under the name mumia, which we are informed
was actually scraped from the mummies taken from tombs. Its
alleged curative properties w r ere explained by the fact that it pre-
served the dead for so many centuries. 64

Josephus Flavins (37 to 95 A.D.}. This Roman historian 66
referred to Dead Sea asphalt stating:

"The changes in the color of the Dead Sea are astonishing, since
it alters three times daily and when the sun's rays change their direc-
tion they are reflected irregularly."

He also describes the use of bitumen in medicine as a remedy
for trachoma, leprosy, gout and eczema.

Plutarch (about 46 A.D.}. This Greek historian Plutarch 66
informs us :

36 HISTORICAL REVIEW I

U A Macedonian named Proxenus, who had charge of the King's
equipage, on opening the ground by the river Oxus (present Turko-
man Republic) in order to pitch his master's tent, discovered a spring
of gross oily liquor, which after the surface was taken off came
perfectly clear and neither in taste nor smell differed from olive oil,
nor was it inferior to it in smoothness and brightness, though there
was no olive tree in that country. It is said indeed, that the water
of the Oxus is of so unctuous a quality, that it makes the skin of
those who bathe in it smooth and shining."

Tacitus (55 to 117 A.D.}. The Roman historian states 67 in
reference to Dead Sea asphalt:

"Those whose calling is to gather asphalt, draw one end into
their boat, whereupon the balance of the mass will follow without
effort. This is continued until the vessel is filled, whereupon the
viscous mass is cut to pieces. . . . This unusual substance floats
in heaps upon the Dead Sea and is either towed or pulled ashore
by hand, where it is easily manipulated. When it is sufficiently
dried, either by the heat of the sun or by the vapors of the earth, it
becomes hard and may be broken up into pieces, as wood or stone,
by means of chisels or the force of axes. . . . The hardening may
be hastened by wetting with vinegar until it acquires the desired
cohesion."

Aelian (Aelianus Claudius] (about laoA.D.). This Roman
writer and rhetorician refers to various sources of asphalt 68

Dioscorides (about 150 A.D.). The Greek physician Dioscori-
des 69 states (I, 83) that there is a source of asphalt, referred to
by him as "Lacus Asphaltites," at Sidon, which is assumed to refer
to Siddim, i.e., to the Dead Sea deposit. He states further that:

"Asphalt is found in its liquid state at Acragantium (the present
Agrigento) in Sicily. It floats on the surface of the springs. It
is a kind of liquid bitumen and is used in lamps in place of olive oil."

He also alludes to Albanian asphalt under the term "pissasphal-
tos" as follows (I, 84) :

"In the vicinity of Epidamnos (i.e. Dirrachion in Albania),
there is found a substance called 'pissasphaltos.' It comes down
from the Ceraunic mountains and is carried along by the force of
the water and deposited on the banks of the rivers, where it is found
in lumps. It smells of pitch mixed with asphalt."

I REFERENCES BY GREEK AND ROMAN WRITERS 37

In reference to Indian asphalt, presumably referring to the de-
posit at the Basti river, near Isakhel, India, in the upper Indus Val-
ley, he comments (I, 83) :

"Bitumen obtained in India is prized most highly, but they do
not disclose the locality where it is found. It is so desirable because
of its purple hue, its heavy weight and characteristic strong odor.
The dark and impure varieties of asphalt are full of faults, since
they have been mixed with pitch, and they come from Phoenicia,
Babylon, Zacynthos and Sidon."

He states that asphalt may be refined:

"By boiling off the fluid constituents, which make the material
so inflammable."

Dioscorides also informs us that:

"The name mumia is given to the drug called 'Bitumen of
Judea,' and to the mumia of the tombs, found in great numbers in
Egypt, and which is nothing more than a mixture which the Byzan-
tine Greeks useci formerly for embalming their dead, in order that
the bodies might remain in the state in which they were buried, and
experience neither decay nor change. Bitumen of Judea is the sub-
stance which is obtained from the Asphaltites Lake."

He mentions (V, 181) that "ampelitis" comes from Selenica,
and "gagates" from Lycia (V, 146) ; also that (I, 85) :

"Asphalt is recommended as a panacea against skin afflictions."

Dion Cassius (155 to 230 A.D.}. This Roman historian
states : 70

"There is Babylon, Trajan saw the asphalt with which the walls
of Babylon had been built. Together with bricks or stones, it pro-
duces such strength that the walls made of it are stronger than rock
and any kind of iron."

Philostratus ( The Elder] (about 200 A.D.). This Athenian
writer 71 refers (I, 23) to asphalt deposits near Ardericca (near
the present town of Kirab) in Cissia (Iran). He states that in
the land of Cissia:

"The soil is drenched with pitch and is bitter to plant in. . . ."

and warns :

"Against drinking water which has been in contact with bitumen,
since this will cause the intestines to close up, owing to the water
taking up traces of bitumen."

although he goes on to say ("Tetrabiblos," I, 2 and 49) :

38 HISTORICAL REVIEW I

"That the drinking of bituminous water is the best remedy for
dropsy."

He also describes :

"An oil which once set afire, cannot be extinguished, and which
Indian kings use to burn down walls and capture cities."

Geoponica (200 to 300 A.D.}. The "Geoponica" 72 consisted
of a collection of writings on husbandry and agriculture by various
Greek and Roman writers of the third and fourth centuries, includ-
ing Gargilius Martialis of Mauretania and Palladius of Rome. In
this treatise we are informed that a mixture of bitumen and oil
served to alleviate wounds in trees (XIII, 10 and 7) ; that rings of
bituminous mastic were made around tree trunks for protection
against ants; that bitumen mixed with sulfur was burned under trees
and bushes to kill caterpillars and other harmful insects, also for
disinfecting the cages of birds (XIV, u, 4) ; that fowls would lay
bigger eggs if rubbed with a mixture of bitumen, resin and sulfur
(XIV, n); that a mixture of bitumen and various spices served
for the treatment of cattle plague (XVII, 16) ; and lastly, that bi-
tumen relieved sufferers of diarrhoea (XVII, 16, i).

Afrlcanus (about 300 A.D.}. This Greek writer, in his treatise
"Kestoi" 73 on agriculture, natural history, military science, etc., de-
scribes a mixture consisting of:

"Sulfur, natural resin (i.e. asphalt), salt and quicklime, which
by careful mixing, the addition of the lime last, and enclosing the
whole in a bronze vessel to exclude humidity, air and light, will
ignite spontaneously by the simple addition of water or dew."

Ammianus Marcellmus (330 to 395 A.D.}. This Roman his-
torian states, 74 probably in reference to the region of Quara and
Quala Shergat in Iraq :

"In Assyria there is asphalt in the lake called Sosingite, in the
bed of which the Tigris is absorbed, which flows on underground to
rise to the surface again at a great distance away. Naphtha also
occurs here; this greatly resembles asphalt and is very viscous and
sticky. Even if a very small bird alights on it, it is drawn down, it
can no longer fly and it disappears into the depths. ^ Once this kind
of substance begins to burn, human intelligence will find no other

I ABOUT 1248 A.D. PIERRE DE JOINVILLE 39

means of quenching it than by earth. A big cleft will be seen in
these districts from which mortally fatal fumes rise up, the heavy
odor of which will kill any living creature coming within its reach."

Theophanes (758 to 817 A.D.}. The Greek writer Theopha-
nes, in his treatise "Chronicles," states:

"The principle of spontaneous ignition by contact with water
was brought to its highest practical application by the Greek archi-
tect Kallinikos residing in Byzantium about 650 A.D., as a fugitive
from the Arabs of the Syrian town of Heliopolis, and who was the
real inventor of 'Greek Fire'." 75

This seems strange, in view of the earlier disclosures by Thu-
cydides(47i~40i B.C.), Hannibal (247-183 B.C.), Pliny the Elder
(23-79 A.D.), Philostratus (about 200 A.D.), and others.

About 950 A.D. Abu-L-Hasan Masudi. The Persian writer
Masudi, in his "Annals" 76 refers to "oleum de gagantis," which is
an oily product derived from natural asphalt by a process termed
"distillatio per decensorium" which was carried out in two superim-
posed jars separated by a screen or sieve. The upper jar, filled with
the material under treatment, was heated by a fire and the oily dis-
tillate allowed to drip through the screen into the bottom jar im-
bedded in damp soil. Medieval writers frequently refer to rock
asphalts and asphaltites under the name "gagates," which was de-
rived from the river Gagas or Gages in Lycia, Asia Minor, at the
mouth of which there was stated to be a deposit of hard asphalt.
Gagates were used as a means of exorcising evil spirits, in which
connection Bishop Marbode of Rennes (1067-1123 A.D.) states in
his treatise "Dactyliothecae" :

"As an amulet it benefits dropsy, diluted with water it prevents
loose teeth from falling out, whilst fumigation with gagates is good
for epileptics. It remedies indigestion and constipation, cures magi-
cal illusions and evil incantations, and is often used in love potions."

About 985 A.D. Abd Al Mukaddasi. This writer refers 7r to:

"Nafta and earth-pitch from Transoxania, Ferghana,"
which corresponds to the present Baku region.

About 1248 A.D. Pierre de Joinville. De Joinville, who ac-
companied King Louix IX on his Sixth Crusade to Damiette, re-
fers 78 to the use of Greek Fire, stating that:

40 HISTORICAL REVIEW I

"Every man touched by it believed himself lost, every ship at-
tacked was devoured by flames."

About 1300 A.D. Marco Polo. This Venetian traveler de-
scribed 70 seepages of liquid asphalt at Baku on the Caspian Sea.
He also mentioned the existence of an ancient fire-temple erected
about the flaming streams of gas and oil, which we are informed
constituted a place of Hindoo pilgrimage.

About 1350 A.D. Sir John Mandeville. This British writer
states (Chap. XXX): 80

"And two myle from Jericho is flom Jordan and you shall wcte
the Dead Sea is right bitter, and this water casteth out a thing
called asphatum, as great pieces as a horse."

1494-1555. Georg Agricola. This well known German metal-
lurgist states : 81

"Bitumen is produced from mineral waters containing oil, also
from liquid bitumen, and from rocks containing bitumen. . . .
Liquid bitumen sometimes floats in large quantities on the surface of
wells, brooks and rivers, and is collected with buckets or other pots.
Small quantities are collected by means of feathers, linen towels
and the like. The bitumen easily adheres to these objects, and is
collected in big copper or iron vessels and the lighter fractions evap-
orated by heating. The residual oil is used for different purposes
and some people mix it with pitch, others with used axle oil to make
it thinner. The bitumen does not harden, even during the time of
its heating in the vessels. Rocks which contain bitumen are treated
in the same way as those which contain sulfur, by heating them in
vessels with a sieve bottom. This, however, is not the common
practice, because the bitumen prepared in this way is not very valu-
able." This process is illustrated in Fig. 23.

Agricola also refers to asphaltic crude-oil seepages at Wietze,
near Hannover, Germany, and mentions the use of "heavy petro-
leum to protect woodwork from rain."

1498. Christopher Columbus. On his third voyage to America
on July 31, 1498, Columbus discovered the island of Trinidad,
where it has been stated: 82 "He careened his galleons and caulked
their storm-racked seams with this natural waterproofing material,"
referring to asphalt derived from Trinidad Lake,

I 1563. CESAR FREDERICKE 41

About 1500. Use of Asphalt in Peru. It has been established
that the Incas of Peru constructed an elaborate system of highways,
some of which were paved with a composition not unlike modern
bituminous macadam.

1535. Discovery of Asphalt in Cuba. G. F. Oviedo y Valdes
of Spain describes 83 a spring of semi-liquid asphalt in the Province
Puerto Principe, near the coast of Cuba, which was used for paint-
ing the hulls of ships. Another occurrence is mentioned on the

From Agricola
FIG. 23. -Smelting Bitumen from Bituminous Rock.

shore of Havana harbor, used for similar purposes. He tells us
that asphaltic petroleum was used to protect woodwork and ma-
sonry in Cuba as early as 1550 A.D.

1563. Cesar Fredericke. This writer in his publication "Voy-
age to the East Indies," states :

"These barks of the Tigris have no pumps in them, because of
the great abundance of pitch, which they have to pitch them with all.
This pitch they have in abundance two days' journey from Babylon.
Near unto the river Euphrates, there is a city called Heit (Hit),
near unto which city there is a great plaine full of pitch, very mar-

42 HISTORICAL REVIEW 1

vellous to beholde, and a thing almost incredible that out of a hole
in the earth, which continually throweth out pitch into the aire with
continuall smoake ; this pitch is thrown with such a force that being
hot it falleth like as it were sprinckled over all the plame in such
abundance that the plaine is always full of pitch. The Mores and
the Arabians of that place say that that hole is the mouth of hell,
and in truth it is a thing very notable to be marked. And by this
pitch the whole of the people have their benefit to pitch their barks.

1595. Sir Walter Raleigh. Sir Walter Raleigh 84 gives a record
of his voyage of exploration to the east coast of South America in
1595, wherein he describes his visit to the Island of Trinidad, and
gives an account of the so-called "Pitch Lake," of which he wrote:

"March 22, 1595 At this point called Tierra de Brea or Piche,
there is that abundance of stone pitch, that all the ships of the
world may be therewith laden from thence, and wee made trial of
it in trimming our shippes to be most excellent goode and melteth not
with the sunne as the pitch of Norway, and therefore for shippes
trading the south parts very profitable."

1599. First Classification of Bituminous Substances. Andreas
Libavius refers to the uses of asphalt, and classified it with mineral
oil, amber and pitch. He endeavored to trace the connection be-
tween asphalt and petroleum, and gives a record of the earliest
literature on asphalt including the works of Pliny, Dioscorides,
ftippocrates and others. 85

1608. William Shakespeare. In his play "Pericles" written in
1608, by Shakespeare (1564-1616), occurs the passage: "We have
a chest beneath the hatches, caulked and bitumened ready."

1656. Early Dictionary Definition of "Bitumen." In one of
the earliest dictionaries of the English language, "Thomas Blount's
Glossary," bitumen is defined as:

"A kind of clay or slime naturally clammy, like pitch, growing
in certain countries of Asia."

It is interesting to note the connection between this interpreta-
tion of the word, and the reference to "slime" and "slimepit" in
"Genesis."

1660. John Milton. In "Paradise Lost," written about 1660
by Milton (1608-1674), we read: "Blazing cressets fed with
naphtha and asphalts"; and again: "The plain, whereon a black

I 1712-1730. VAL DE TRACERS, LIMMER, SEYSSEL DEPOSITS 43

bituminous gurge boils out from underground the mouth of hell."
1661. Commercial Production of Wood Tar. The earliest ref-
erence to the production of wood tar on a large scale by the dry
distillation of wood, occurs in Robert Boyle's "Chemistra Scepticus,"
1 66 1. This industry is said to have been first practiced in Norway
and Sweden.

1672. First Accurate Description of Persian Asphalt Deposits.
Dr. J. Fryer accurately describes the occurrences of asphalt in the
East Indies and Persia, in his book u Nine Years' Travels" (1672
i68i). 86 .

1673. Discovery of Elaterite. The first description of elater-
ite, originally found at Castleton in Derbyshire, England, under
the name "Elastic Bitumen," is given by M. Lister in the Philo-
sophical Magazine and Journal of Science ^ London, 1673 (p.
6179).

1681. Discovery of Coal Tar and Coal-Tar Pitch. In a patent
(No. 214) taken out in England on August 19, 1681, by Joachim
Becher and Henry Serle, entitled "A new way of makeing pitch, and
tarre out of pit coale, never before found out or used by any other,"
we find the first description of coal tar and coal-tar pitch, as well as
their methods of production.

1691. Discovery of Illuminating Gas from Coal. Dr. John
Clayton, dean of Kildare, England, experimented with the inflam-
mable gas obtained on heating coal in a closed retort. He filled
bladders with this gas and demonstrated that it burnt with a lumi-
nous flame.

1694. Discovery of Shale Tar and Shale-Tar Pitch. British
Patent No. 330, of 1694 (Jan. 29), entitled 4< Pitch, tar and oyle,
out of a kind of stone from Shropshire," granted Martin Eele,
Thomas Hancock and William Portlock, contains the earliest record
of the manufacture of shale tar and shale-tar pitch.

1712-1730. Discovery of Val de Travers, Limmer and Seyssel
Asphalt Deposits. The asphalt deposit at the Val de Travers in
the Jura Mountains, Canton of Neuchatel, Switzerland, was dis-
covered by the Greek Doctor Eirinis d'Eyrinys in 1712, and de-
scribed in detail. 87

Some give Eyrinys the credit of having likewise discovered the
Limmer asphalt deposit near Hanover, Germany, in 1730, but this

44 HISTORICAL REVIEW J

has not been definitely established. A third discovery of asphalt by
Eyrinys, in 1735, at Seyssel in the Rhone Valley, Department of
Ain, France, proved to be one of the most important deposits in
Europe. This has been worked constantly up to the present time,
and will be described later.

1772. First Use of Tar for Flat Roofs. Recent researches
ascribe P. J. Marperger of Berngau, near Neumarkt (in the vicin-
ity of Niirnberg, Germany) as the originator of tarred roofs. He
described the following method of covering flat roofs: the wooden
boards were first caulked with oakum, then sprinkled alternately
with tar and a mixture of fine sand with iron slag, until after three
or four such treatments a fairly thick protective covering was ob-
tained. 88

1746. Invention of the Process of Refining Coal Tar. On
Dec. 2, 1746, a patent (No. 619) was granted in England to Henry
Haskins disclosing: "A new method for extracting a spirit or oil
from tar, and from the same process obtaining a very good pitch;"
consisting of our present process of fractional distillation in a closed
retort connected with a worm condenser.

1752. Samuel Foote. The English dramatist Foote (1720-
1777) writes in his book "Taste," published in 1752, of the "salu-
tary application of the asphaltum pot" for preserving the beautify-
ing qualities of the complexion. At this time it was claimed by
authorities to be. "a sure cure for ringworm, boils, gout, epilepsy,
blindness, toothache and colic."

1777. First Exposition of Modern Theory of the Origin of
Asphalt. In his "Elements de Mineralogie," published in 1777
LeSage 89 classified bitumens in the sequence : "Naphtha, petroleum,
mineral pitch, maltha and asphalt," and regarded them all as origi-
nating from petroleum oil. This closely conforms to the modern
views regarding the classification and origin of bitumens.

1788. Discovery of Lignite Tar. Krimitz in 1788 referred to
the production of "a tar-like oil" upon destructively distillating
"earth coal" (lignite). This was virtually the first description of
the manufacture of lignite tar.

1780-1790. Discovery of "Composition" or "Prepared" Roof-
ing. Arvicl Faxe of Sweden 9d is given credit for having produced
the first composition roofings between the years 1780 and 1790 in

I 1815. COMMERCIAL EXPLOITATION OF COAL-TAR SOLVENTS 45

the following crude manner : the roof boards were first covered with
plain paper, impregnated with a mixture of copper and iron sul-
fates, which, after being nailed in place, was coated with heated
wood tar to make it 'waterproof, and then surfaced with various
colored mineral earths.

A newspaper published in Leipsic in the year 1791 credits
Michael Kag of Miihldorf, Bavaria, with having produced an im-
proved form of prepared roofing by saturating raw paper with var-
nish, and coating the surfaces with a mineral powder. The product
was also recommended as a substitute for leather in the soles of
shoes.

Similarly, the Magdeburg Zeitung on Nov. 16, 1822, contained
a notice stating that paper impregnated with tar is being used to
displace straw and wooden shingles for roofing purposes, and that
the former may be made fire-resistant by treating the tar with
unslaked lime and surfacing with sand.

The manufacture of "tarred board" for roofing purposes, as
practiced in Germany during the year 1828, was published by W. A.
Lampadius. 01

1792-1802. Manufacture of Coal Gas and Coal Tar on a Large
Scale. Wm. Murdoch, of England, was the first to manufacture
coal gas and coal tar on a large scale.

1797-1802. Exploitation of Seyssel Asphalt in France. M.
Secretan obtained a concession from the French Government to
work the asphalt deposits at Seyssel on the Rhone, France, in the
fifth year of the French Republic (1797). The venture, however,
did not prove a success. The deposit was next taken over by Count
de Sassenay, of France, in 1802, and actively exploited. A labora-
tory was erected to investigate the uses of this asphalt, which was
marketed in France under the name "rock asphalt mastic," and used
for surfacing floors, bridges and sidewalks, also to a limited extent
for waterproofing. The earliest experimental use was in the vicinity
of Bordeaux and Lyons.

1815. Commercial Exploitation of Coal-Tar Solvents. In
1815, F. C. Accum, of England, obtained "naphtha" by subjecting
coal tar to fractional distillation on a commercial scale. This distil-
late was used in the manufacture of India rubber goocfc, for burn-
ing in open lamps and for certain kinds of varnish. The tar which

46 HISTORICAL REVIEW I

remained behind had no particular value and was accordingly con-
sumed as fuel.

1820. Manufacture of Asphalt-saturated Packing Papers in
Switzerland. The asphalt deposits previously discovered at Neu-
chatel, Switzerland, were utilized in 1820 for impregnating porous
paper, for use as tarpaulins, packing paper, imitation oil-cloth, etc.,
and the first factory was established in Geneva. 92

1822. Discovery of Scheererite and Hatchettite. The mineral
wax Scheererite was discovered in a bed of lignite (brown coal) at
Uznach, near St. Gall in Switzerland, by Captain Scheerer, in
i823. 93 In the same year the mineral wax hatchettite or hatchetine
was discovered on the borders of Loch Fyne, in Argyllshire, Scot-
land, and was named after the English chemist, C. Hatchctt. 94

1830. Discovery of Paraffin Wax. The discovery of paraffin
wax is credited to Carl von Reichcnbach, of Stuttgart, Germany,
who was the first to describe its physical and chemical properties. 95
He derived the material from lignite tar and christened it "paraffin"
(parum affinis), because of its unusual resistance to chemicals.

1832. Coal Tar First Used for Paving. The first stretch of
tar-macadam pavement on record was laid in Gloucestershire, Eng-
land, between 1832 and 1838. In this same connection, an inter-
esting pioneer patent was granted to Cassell in 1834, describing the
use of coal tar for surfacing roads, grouting, and the construction
of tar-concrete paving blocks. 96

1833. Discovery of Ozokerite. The first reference to the min-
eral ozokerite was by E. F. Glocker 97 in 1833. lie discovered it
near the town of Slanik in Moldavia, close to a deposit of lignite
at the foot of the Carpathians. It was named from the Greek
words signifying u to smell" and "wax," in allusion to its odor.

1835. First Asphalt Mastic Foot Pavements Laid in Paris.
It is recorded that on June 15, 1835, the first mastic pavement was
laid at Pont Royal, Paris, composed of Scyssel asphalt. 98

1836. Asphalt First Used in London for Foot Pavements.
In 1836 we first hear of Seyssel asphalt being introduced from
France to London for constructing foot paths. 99

1837. Publication of First Exhaustive Treatise on the Chem-
istry of Asphalt. The well-known treatise "Memoir sur la compo-
sition des bitumes" was published by J. B. Boussingault in the year

I 1850. DISCOVERY OF "ASPHALTIC COAL" IN NEW BRUNSWICK 47

1837. It was the most exhaustive treatise on the subject which had
yet appeared, and was the first to propose the use of the terms
"petrolene" and "asphaltene" for the components of asphalt 100

1837. Discovery of Bituminous Matter in the United States.
In 1837 appeared the first report of an asphalt deposit in the United
States in which semi-solid and solid bitumens were reported in the
Connecticut valley at Farmington, Hartford (Rocky Hill), Berlin,
Middletown and New Britain, Conn. 101

1838. Discovery of Process for Preserving Wood with Coal-
tar Creosote. In 1838 Bethell disclosed the use of coal-tar oil for
impregnating wood. 102

1838. Asphalt First Used in the United States for Foot Pave-
ments. The earliest case on record of rock asphalt being used in
the United States for sidewalks is in the portico of the old Mer-
chants' Exchange Building, Philadelphia, in 1838. Seyssel asphalt
was used for this purpose.

1841. First Use of Wood Block Pavement. Wood blocks im-
pregnated with coal tar were first used in England. 103

1843. Bituminous Matters Discovered in New York State.
L. C. Beck, in 1843, wrote a paper on the occurrence of bituminous
matter in several of the New York limestones and sandstones. 104

1844-1847. First Composition Roofing in the United States.
Rev. Samuel M. Warren reported that in 1844-1845 roofs were
first laid in Newark, N. J., consisting of square sheets of ship's
sheathing paper treated with a mixture of pine tar and pine pitch,
and surfaced with sand. In 1847 coa ^ tar was used as a substitute
for the pine tar, to soften the pine pitch, and employed as a saturant
for the paper. Fine gravel was next used to substitute the sand.
The square sheets were dipped into the melted mixture by hand,
sheet by sheet, and then the excess was pressed out The next step
consisted in running the paper or felt in rolls through continuously
operating saturators designed to saturate with tar. Finally, in
Buffalo, N. Y., coal tar was distilled down to a roofing pitch, which
was used to replace the more expensive mixture of pine pitch and
coal tar. The foregoing constituted * the origin of the "tar-and-
gravel roof," so extensively used to-day. 105

1850. Discovery of "Asphaltic Coal" in New Brunswick,
Nova Scotia. C. T. Jackson published the first accounts of Nova

48 HISTORICAL REVIEW I

Scotia "albertite" in the years 1850-1851. It was described as
"Albert Coal." 106

1852. First Modern Asphaltic Road. The first asphaltic road
of which we have a record in comparatively modern times, was con-
structed in 1852 from Paris to Perpignan, France, after the fashion
of modern macadam construction, from Val de Travers rock-
asphalt.

1854. First Compressed Asphalt Roadway Laid in Paris.
In 1854 a short stretch of compressed rock asphalt roadway was
laid in Paris by M. Vaudrey. 107 This, we are told, was the outcome
of observations previously made by a Swiss engineer, M. Merian,
who in 1849 noted that fragments of rock asphalt which fell from
the carts transporting the material from the mine at Val de Travers,
to the nearby village, became compressed in summer under the
wheels into a crude pavement of asphalt. M. Leon Malo in con-
junction with M. Vaudrey and M. Homberg thereupon con :
structed a stretch of roadway compacted with a roller in the
Rue Bergere, Paris, which was maintained in good condition for
sixty years. 108

1858. First Modern Asphalt Pavement Laid in Paris. In
1858 the first large area of asphalt roadway was constructed on the
Palais Royal and on the Rue St. Honore in Paris. It was cortiposed
of a foundation of concrete 6 in. thick surfaced with rock asphalt
mastic obtained from the Val de Travers deposit, compressed to a
layer about 2 in. thick. This constituted the earliest use of sheet
asphalt pavement in its modern form.

1863. Discovery of Grahamite in West Virginia. The first
account of the West Virginia grahamite deposit is given by J. P.
Lesley. 100 The material was described as a "rock asphalt," but was
later named "grahamite" by Henry Wurtz, in honor of the Messrs.
Graham, who were largely interested in the mine.

1869. The First Compressed Asphalt Pavement in London.
The first stretch of asphalt roadway in London was laid at Thread-
needle Street near Finch Lane in May, 1869. It was composed of
Val de Travers rock asphalt. 1 *

1870-1873. First Asphalt Roadways in the United States.
Some give the Belgian chemist, E. J. De Smedt, credit for having
the first rock asphalt roadway in t u ~ TT ~ : ted States r contending

I 1885. DISCOVERY OF UINTMITE (GILSONITE) IN UTAH 49

that in 1870 a small experimental strip was laid with continental
asphalt opposite the City Hall in Newark, N. J. In 1871 pavements
were laid in Washington, D. C, in accordance with a patent granted
to N. B. Abbott, 111 composed of a mixture of crushed rock and sand
with coal-tar pitch and creosote oil, after a favorable report had
been rendered by a special commission appointed by Congress.
These pavements gave good service for over 15 years. Also in
1871, a small stretch of pavement was laid in Battery Park, New
York City, and according to T. H. Boorman, 112 in 1872 a larger
stretch was laid at Union Square, composed of Val de Travers rock
asphalt. It is also reported that in 1873 a similar pavement was
laid in front of the Worth Monument, which remained in use until
i886. 113

1876. First Trinidad Asphalt Pavement Laid in the United
States. According to Clifford Richardson 114 the first sheet asphalt
pavement of Trinidad asphalt to be laid in the United States was on
Pennsylvania Avenue, Washington, D. C. This was authorized by
an act of Congress passed in 1876, Val de Travers rock asphalt
being used from the Capitol to Sixth Street, and Trinidad asphalt
for the remainder. The rock asphalt w r as subsequently pronounced
to be too slippery and the Trinidad asphalt pavement a success.

1880. Use of Asphalt "Chewing-gum" in Mexico. B. de
Sahagun 115 informs us that the inhabitants of the coastal districts of
Mexico, the Totonacs, collected asphalt ("tzacutli") in the Panuco
river region and sold it to the Aztecs of the interior, who in turn
compounded it with gum chicle ("txixtli") and used the mixture as
chewing-gum ( "chapopotli" ) .

1881. Use of Chemicals for Oxidizing Coal Tars and Petro-
leum Asphalts. The first complete disclosure of the process for
"oxidizing" bituminous materials was by E. J. De Smedt. 116 This
process consisted in evaporating coal tar or asphalt in contact with
substances capable of inducing oxidation (such as potassium per-
manganate), "to give them greater tenacity and render them, or the
pavement, or other compositions in which they enter, less brittle and
less liable to be affected by air or water."

1885. Discovery of Uintaite (Gilsonite) in Utah. Gilsonite,
first known as "uintaite," was discovered in the Uinta Valley near
Fort Duchesne, Utah, in 1885. It was first described by W. P.

50 HISTORICAL REVIEW I

Blake 11T and was later called "gilsonite," after S. H. Gilson, of
Salt Lake City.

1889. Discovery of Wurtzilite in Utah. W. P. Blake subse-
quently discovered a deposit of wurtzilite not far from the source of
gilsonite in the Uinta Valley, Wasatch County, Utah, between Salt
Lake and the valley of*the Green river. 118 It was named after Dr.
Henry Wurtz of New York.

1891. Exploitation of the Bermudez Asphalt Deposit, Vene-
zuela. According to Hippolyt Kohler and Edmund Graefe, 119 the
Bermudez asphalt deposit in Venezuela was first developed in the
year 1891 by the New York-Bermudez Company, and subsequently
taken over by the Barber Asphalt Paving Co. A search of the lit-
erature fails to reveal when this deposit was first discovered.

1892. Use of Bermudez Asphalt on a Large Scale. Bermudez
asphalt was first used extensively in Detroit, Mich., in 1892, and
the year following in Washington, D. C With this start, it rapidly
gained in popularity, and is to-day largely used as a road binder, as
well as for sheet-asphalt pavements.

1894. Use of Air for Oxidizing Petroleum Asphalt. A further
development of the De Smedt process for oxidizing petroleum as-
phalt was brought about by F. X. Byerley, of Cleveland, O., who
blew air through asphaltic oils maintained at a temperature of
600 F. 120 The resulting product, marketed under the name of
"byerlite," attained great popularity.

CHAPTER II

TERMINOLOGY AND CLASSIFICATION OF BITUMINOUS

SUBSTANCES

One of the most baffling problems with which we have had to
deal in recent years is fixing the definitions of the various bituminous
substances, and the products in which they are used in the arts. 1

The words "bitumen," "asphalt/' "resin," "tar," "pitch,"
"wax," have been in use for many centuries, most of them long
before the advent of the English language. At first, very little was
known regarding the properties of these substances, and, as a result,
the early writers used these terms loosely, and, in many cases, inter-
changeably. It is probable that each of these words at first related
to the aggregate characteristics of some typical substance closely
associated with the processes of daily life. As nothing of the chem-
istry was known when these terms originated, they were at first
differentiated solely by their physical characteristics.

The words originally had but a limited meaning, but as new
members of these groups of substances were discovered, the terms
were extended in scope until the various expressions completely out-
grew their original bounds. This resulted in a certain amount of
overlapping and ambiguity.

As the chemistry of these substance gradually became known,
this means was likewise adopted to differentiate between them, but
we are still compelled to rely principally upon the physical charac-
teristics in arriving at a rational basis of terminology, as their chem-
istry has been unravelled to but a limited extent.

In defining a substance, we must rely on one or more of the fol-
lowing criteria :

Origin, Solubility,

Physical Properties, Chemical Composition.

The last three can be more or less readily ascertained from an
examination of the substance itself. The origin, however, is not

52 TERMINOLOGY AND CLASSIFICATION II

always apparent, but in certain cases may be deduced by inference.
To base a definition solely upon a statement of the origin of a sub-
stance would necessitate some prior knowledge concerning its source
or mode of production. As such knowledge is not always available,
a definition of this kind would be very limited in its scope. Unfor-
tunately, this plan has often been followed by many of the leading
technical societies in this country and abroad, in fixing the defini-
tions of bituminous substances.

A far better method consists in basing the definition upon the
inherent characteristics of the substance itself, so as to permit of its
identification without necessarily having prior knowledge concerning
its origin.

The four cardinal features forming this latter basis of nomencla-
ture may be further elaborated as shown in Table I.

In Table II the principal types of bituminous substances are
classified according to the features enumerated in Table I.

The definitions which follow are based upon this classification.
Although reference is made to the origin of the substance, neverthe-
less, this is but incidental, and with the exception of the generic
terms, the definitions would be explicit even though this feature were
omitted.

Bituminous. Substances.* A class of native and pyrogenoust
substances containing bitumens or pyrobitumens, or resembling
them in their physical properties.

SCOPE. This definition includes bitumens, pyrobitumens, py-
rogenous distillates and tars, pyrogenous waxes and pyrogenous resi-
dues (pitches and pyrogenous asphalts).

Liquid Bituminous Materials. Those having a penetration at
25 C. (77 F.), under a load of 50 g. applied for one second,
of more than 350 (Test gb).

Semi-Solid Bituminous Materials. Those having a penetration

* The scope of the word "bituminous*' is based on the commonly accepted interpreta-
tion of the suffix "ous," signifying: (i) to contain; (2) to resemble, to partake of the
nature, to have the qualities (e.g., silicious: containing silica or resembling silica;
resinous: containing or resembling resin; oleaginous: containing or resembling oil; cal-
careous:, containing or resembling lime). Similarly, the word "bituminous" is construed
to include substances, either containing more or less bitumen (or pyrobitumen), or else
resembling them in their appearance or qualities.

fThe expression "pyrogenous" implies that the substance was produced by means of
heat or fire.

BITUMINOUS SUBSTANCES

Origin

Solubility

Chemical
Compo-
sition

Native

Pyrogenous

TABLE I

r Mineral
I Vegetable
I Animal

Factional distillation
Destructive distillation
Heating in a closed vessel
Blowing with air.

Color in Mass H

r Light (white, yellow or brown)
Dark (black)

Consistency
or Hardness

Liquid
Viscous
Semi-solid
Solid

Fracture j

Conchoid al
Hackly

Physical

Properties

Lustre j

:Waxy
Resinous
Dull

Feel

Odor

Volatility

Fusibility

f Adherent
< Non-adherent
I Unctuous (waxy)

I Oily (petroleum-like)
I Tarry

f Volatile

( Non-volatile

f Fusible

] Difficultly fusible

I Infusible (melts only with decomposition)

Non-mineral constituents soluble in carbon disulfide

Hydrocarbons (compounds containing carbon and hydrogen)
Oxygenated bodies (compounds containing carbon, hydrogen, and

oxygen)

Crystallizable paraffins (crystallize at low temperatures)
Mineral matter (inorganic substances).

at 25 C. (77 F.)> under a load of 100 g. applied for five seconds,
of more than 10, and a penetration at 25 C. (77 F,) , under a load
of 50 g. applied for one second, of not more than 350 (Test 9^).

Solid Bituminous Materials. Those having a penetration at
25 C. (77 F.), under a load of 100 g. applied for five seconds, of
not more than 10 (Test

TERMINOLOGY AND CLASSIFICATION

ilii if ujs

,. 8 a 8 3 rS ^ ^3.>'S w^-gw

il ti

il I

lti Jill

I I

3T3

iJi

r? M's.a'gj'g 44

H|8 ^

i I

I I
*

II BITUMEN 55

Bitumen,* A generic term applied to native substances of vari-
able color, hardness and volatility; composed principally of hydro-
carbons, substantially free from oxygenated bodies ; sometimes asso-
ciated with mineral matter, the non-mineral constituents being fusible
and largely soluble in carbon disulfide, yielding water-insoluble sul-
fonation products.

SCOPE. This definition includes petroleums, native asphalts,
native mineral waxes and asphaltites (gilsonite, glance pitch and
grahamite).

Pyrobitumen.t A generic term, applied to native substances of
dark color; comparatively hard and non-volatile; composed of hy-
drocarbons, which may or may not contain oxygenated bodies;
sometimes associated with mineral matter, the non-mineral constitu-
ents being fusible and relatively insoluble in carbon disulfide.

SCOPE. This definition includes the asphaltic pyrobitumens
(elaterite, wurtzilite, albertite and impsonite) also the non-asphaltit
pyrobitumens (peat, lignite, bituminous coal and anthracite coal)
and their respective shales.

Petroleum. A species of bitumen, of variable color, liquid con-
sistency, having a characteristic odor; comparatively volatile; com-
posed principally of hydrocarbons, substantially free from oxy-
genated bodies; soluble in carbon disulfide, yielding water-insoluble
stilfonation products.

SCOPE. This definition includes non-asphaltic, semi-asphaltic
and asphaltic petroleums.

Mineral Wax. A term applied to a species of bitumen, also to
certain pyrogenous substances; of variable color, viscous to solid
consistency; having a characteristic lustre and unctuous feel; com-
paratively non-volatile; composed principally of saturated hydro-
carbons, substantially free from oxygenated bodies ; containing con-
siderable crystallizable paraffins; sometimes associated with mineral

* The interpretation of the term "bitumen" as employed in this treatise is entirely dis-
sociated from the idea of solubility (in certain solvents for hydrocarbons), and has no
connection whatsoever with the inappropriate expression "total bitumen," used in many
contemporary text-books to designate the amount soluble in carbon disulfide, and which
unfortunately is largely responsible for the existing confusion in terminology.

fThe expression "pyrobitumen" implies that the substance when subjected to heat or
fire will generate, or become transformed into bodies resembling bitumens (in their solu-
bility and physical properties).

56 TERMINOLOGY AND CLASSIFICATION II

matter, the non-mineral constituents being easily fusible and soluble
in carbon disulfide, yielding water-insoluble sulfonation products.

SCOPE. This definition is applied to crude and refined native
mineral waxes, also to pyrogenous waxes. Crude native mineral
waxes include ozokerite. Refined native mineral waxes include
ceresine (refined ozokerite) and montan wax (extracted from lig-
nite or pyropissite by means of solvents). Pyrogenous waxes in-
clude the solid paraffins separated from non-asphaltic and semi-
asphaltic petroleums, peat tar, lignite tar and shale tar.

Asphalt. A term applied to a species of bitumen, also to certain
pyrogenous substances of dark color, variable hardness, compara-
tively non-volatile; composed principally of hydrocarbons, substan-
tially free from oxygenated bodies; containing relatively little to
no crystallizable paraffins; sometimes associated with mineral mat-
ter, the non-mineral constituents being fusible, and largely soluble
in carbon disulfide, yielding water-insoluble sulfonation products.

SCOPE. This definition is applied to native asphalts and pyrog-
enous asphalts. Native asphalts include asphalts occurring natur-
ally in a pure or fairly pure state, also asphalts associated naturally
with a substantial proportion of mineral matter.* The associated
mineral matter may be sand, sandstone, limestone, clay, shale, etc.
Pyrogenous asphalts include residues obtained from the distillation,
blowing, etc., of petroleums (e.g., residual oil,t blown asphalts,t
residua! asphalts,! sludge asphalt, 1 1 etc.), also from the pyrogenous
treatment of wurtzilite (e.g., wurtzilite asphalt 1T).

In Europe, the term "asphalte" is applied to unconsolidated
limestone impregnated with asphalt, which softens and crumbles
when subjected to a moderate heat (e.g., 125 to 1 60 F.), whereas
the term "bituminous rock" is used to designate consolidated lime-
stone rock impregnated with asphalt, which resists high tempera-
tures (e.g., 1000 F. and over) without crumbling.

Asphaltite. A species of bitumen, including dark-colored, com-
paratively hard and non-volatile solids; composed principally of

* Often termed "rock asphalts."

f Produced by the dry distillation of non-asphaltic petroleum, the dry or steam dis-
tillation of semi-asphaltic petroleum and the steam distillation of asphaltic petroleum.

t Produced by blowing air through heated residual oils.

Produced by the steam distillation of semi-asphaltic and asphaltic petroleums.

|| Produced from the acid sludge obtained in the purification of petroleum distillates
with sulfuric acid.

fl Produced by depolymerizing wurtzilite in closed retorts.

II TAR 67

hydrocarbons, substantially free from oxygenated bodies and crys-
tallizable paraffins; sometimes associated with mineral matter, the
non-mineral constituents being difficultly fusible, and largely soluble
in carbon disulfide, yielding water-insoluble sulfonation products.

SCOPE. This definition includes gilsonite, glance pitch, and
grahamite.

Asphaltic Pyrobitumen. A species of pyrobitumen, including
dark-colored, comparatively hard and non- volatile solids ; composed
of hydrocarbons, substantially free from oxygenated bodies ; some-
times associated with mineral matter, the non-mineral constituents
being infusible and largely insoluble in carbon disulfide.

SCOPE. This definition includes elaterite, wurtzilite, albertite,
impsonite and the asphaltic pyrobituminous shales.

Non-asphaltic Pyrobitumen. A species of pyrobitumen, inclucj-
ing dark-colored, comparatively hard and non-volatile solids; com-
posed of hydrocarbons, containing oxygenated bodies ; sometimes
associated with mineral matter, the non-mineral constituents being
infusible, and largely insoluble in carbon disulfide.

SCOPE. This definition includes peat, lignite, cannel coal, bitu-
minous coal, anthracite coal, and the non-asphaltic pyrobituminous
shales.

Tar. A term applied to pyrogenous condensates obtained in the
destructive distillation of organic materials; of dark color, liquid
consistency; having characteristic odors; comparatively volatile at
high temperatures; composed principally of hydrocarbons, some-
times associated with carbonaceous matter, the non-carbonaceous
constituents being largely soluble in carbon disulfide, yielding water-
soluble sulfonation products.

SCOPE. This definition includes the volatile oily decomposition
products obtained from the pyrogenous treatment of petroleum
(water-gas tar and oil-gas tar), bones (bone-tar), wood and roots
of coniferae (pine tar), hardwoods, such as oak, maple, birch, and
beech (hardwood tar), peat (peat tar), lignite (lignite tar), bitu-
minous coal (gas-w r orks coal tar, coke-oven coal tar, blast-furnace
coal tar, producer-gas coal tar, etc.), and pyrobituminous shales
(shale tar).

58 TERMINOLOGY AND CLASSIFICATION II

Pitch. A term applied to pyrogenous residues obtained in the
distillation of organic materials; of dark color, viscous to solid con-
sistency; comparatively non-volatile, fusible; composed principally
of hydrocarbons; sometimes associated with carbonaceous matter,
the non-carbonaceous constituents being largely soluble in carbon di-
sulfide, yielding water-soluble sulfonation products.

SCOPE. This definition includes residues obtained from the dis-
tillation of tars (oil-gas-tar pitch, water-gas-tar pitch, bone-tar
pitch, wood-tar pitch, peat-tar pitch, lignite-tar pitch, gas-works
coal-tar pitch, coke-oven coal-tar pitch, blast-furnace coal-tar pitch,
producer-gas coal-tar pitch, and shale-tar pitch) ; also from the dis-
tillation of fusible organic substances, the process having been termi-
nated before the formation of coke (rosin pitch and fatty-acid
pitch) ; also anthracene pitch, naphthol pitch, cresol pitch, ozokerite
pitch, montan pitch, rubber pitch, gutta-percha pitch, etc., known in
Germany as "Immediate Pitches," i.e., produced directly (immedi-
ately) on distillation, without the initial formation of tars, 2

In Germany, the terms "Chemopeche" and "Chemoasphalte"
are used to designate pitches and asphalts, respectively, which are
produced as the result of chemical reactions, including the fol-
lowing : 8

(a) Precipitation products, resulting from the precipitation or
selective extraction by means of solvents.

(b) Oxygenated products, resulting from the treatment with
air, oxygen, ozone, etc., at elevated temperatures, e.g. blown petro-
leum asphalt, blown coal-tar pitch, etc.

(c) Hydrogenated products, resulting from treatment with hy-
drogen in the presence of a catalyst at elevated temperatures, and
distillation of the resultant product.

(d) Reaction with mineral acids (i.e., sulfuric, nitric, phos-
phoric, etc.) and evaporation or distillation of the residue, e.g.
sludge asphalt.

(e) Reaction with alkalies and subsequent precipitation, extrac-
tion, or distillation of the resultant product.

(f) Reaction with sulfur or sulfur derivatives at elevated tem-
peratures, e.g. sulfurized asphalts and pitches.

(g) Reaction with halogens (e.g. chlorine, iodine, etc.).
(h) Reaction with phosphorus and its derivatives.

[i) Reaction with metallic salts; either solid salts at elevated
temperatures, or aqueous solutions of metallic salts in refining op-
erations, and separation of the resultant polymerized product

II BITUMINOUS SUBSTANCES 59

(j) Reaction with sundry chemicals (e.g. formaldehyde and its
derivatives, furfurol, etc.).

It will be noted that the terms "asphalt" and "mineral wax"
are each applied indiscriminately to native and pyrogenous sub-
stances. This is due to the fact that at the present time it is prac-
tically impossible to distinguish between certain native and pyroge-
nous asphalts or mineral waxes, either by physical or chemical means.
It is probable that some method may be discovered for accomplish-
ing this, in which event it would be of decided advantage to frame
separate definitions to distinguish between native and pyrogenous
substances respectively. With the knowledge available at present,
however, this cannot readily be accomplished. We must be content,
therefore, to apply the terms "asphalt" and "mineral wax" both to
native substances and to manufactured (pyrogenous) products.

In many of the early classifications, natural gas and marsh gas
were included within the scope of the term "bitumen." As this
stretches the meaning to an abnormal extent, the author deems it
inadvisable to include natural gases in the definitions and classifica-
tions given in this treatise.

The terms "maltha" (derived from the Greek /*<IX0a), "brea"
and "chapapote" (of Mexican Spanish origin), "goudron minerale"
(French), "Bergteer" (German), "kir" (Russian), 4 and "mineral
tar" (English), frequently found in contemporary classifications to
designate the softer varieties of native asphalt, have been omitted
for the sake of brevity.

When it comes to classifying bituminous substances, the inter-
pretation of the word "bitumen" represents the crux of the entire
matter. An analysis of the views concerning the scope of this term,
prevalent in America and abroad, shows that they may be grouped
into four classes, which will be listed in the order of their breadth,
commencing with the one having the narrowest scope :

(a) Bitumens naturally occurring hydrocarbons.

(b) Bitumens naturally occurring hydrocarbons, likewise resi-

dues obtained from the distillation of petroleum (e.g.,
petroleum asphalts).

dues obtained from the distillation of petroleum, likewise
artificial hydrocarbon substances (e.g., tars and pitches).

60 TERMINOLOGY AND CLASSIFICATION II

(d) Bitumens only those components of (c) which are soluble
in carbon disulfide.

View (a) represents the layman's interpretation of the word, as
is reflected in the principal dictionaries of both abroad and America.
It is obvious from these definitions that the word ''bitumen'' has for
generations been confined to hydrocarbon substances which occur
in nature, and distinctly excludes hydrocarbon substances produced

artificially. .

View (b) is supported by the British Engineering Standards
Association, also by Dr. Heinrich Mallison in Germany. This in-
volves a slight departure from View (a), including as it does, resi-
dues obtained from the distillation of petroleum.

View (c) is still somewhat broader than (b), being extended to
include tars and pitches. It is supported abroad by David Holde
and Wilhelm Reiner and others. ,

View (d) has been adopted in principle by the American Society
for Testing Materials, 5 and the American Standards Association.

Now the question arises as to whether there is any need or justi-
fication of extending the dictionary definitions embodied in View
(a). In other words, has the scientific fraternity the right to change
or modify what has been the common heritage of the people, without
some particularly good reasons ? The only apparent justification for
extending the scope of the word "bitumen" as reflected in Views (b)
and (c) is to include certain products which have been developed
and produced since the word was originally adopted such products
as petroleum asphalts, tars and pitches. Parenthetically, there
seems to be but little justification to extend the word "bitumen"
to include petroleum asphalts (as outlined in View &), since the
prpcess of distillation has a marked effect on the nature of the
asphalt originally present in the petroleum. At the high end-tem-
peratures at which the distillation process is conducted (600 to
800 F.) a form of polymerization takes place, whereby asphalt-like
substances are produced. In other words, the percentage of asphalt
in the petroleum is increased under these conditions. It follows
therefore, that the petroleum asphalts produced commercially, differ
in their physical and chemical properties from the asphalt originally
present in the petroleum, or separated in nature by a slow natural
process of evaporation.

If the word "bitumen" is broadened in accordance with View (c)

H BITUMINOUS SUBSTANCES 61

it will become synonymous with the word "bituminous substance"
so that both expressions will have an identical meaning.

Singularly, there seems to be but very little difference of opinion
at the present time with respect to the expression * 'bituminous sub-
stance." In this, the scientific fraternity seems to be in accord with
the dictionary definitions. It is the consensus of opinion that the
expression "bituminous substance" represents a form of substance
which contains bitumens, or resembles bitumens, or constitutes the
source of bitumens. This is based on a commonly accepted interpre-
tation of the suffix "ous," signifying:

i to contain;

2 to resemble, to partake of the nature, or to have the qual-
ities of.

This raises the question as to whether or not language as it exists
at present does not furnish us with sufficient tools to answer our
needs. Is not the expression "bituminous" ("bituminous sub-
stance") of sufficient breadth to include "bitumens" (i.e., naturally
occurring hydrocarbons) as well as petroleum asphalts, tars and
pitches? Is it not true that petroleum asphalts, tars and pitches
resemble "bitumens" or partake of their nature in respect to their
physical properties? Then why broaden the scope of the word "bi-
tumen" so as to make it synonymous with the expression "bituminous
substance"? The author can see no justification or necessity for so
doing.

Moreover, View (d) is so technical, that it is questionable
whether the laity will ever accept it. Its proponents maintain that
the only way to determine whether or not a substance is a "bitumen"
is to subject it to chemical analysis, to find out what proportion is
soluble in carbon disulfide. According to this view, the presence of
any associated mineral constituents or hydrocarbons insoluble in
carbon disulfide would disqualify the original substance as a "bitu-
men" even though it occurred as such in nature.

The author therefore advocates that the words "bitumen" and
"bituminous substance" be defined in scope as expressed in View
(a), which is exactly as they have been heretofore used and accepted
in the language. He believes further that by using these two terms
co- jointly, a satisfactory system of classification may be devised,
which will answer adequately the needs of the scientific fraternity,

TERMINOLOGY AND CLASSIFICATION

S I

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BITUMINOUS SUBSTANCES

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64 TERMINOLOGY AND CLASSIFICATION II

and at the same time be in complete harmony with the dictionary
definitions as they now exist.

With the foregoing in mind, the author has worked out a basis
for classifying bituminous substances, including the most important
members recognized commercially, which will be found in Table III.

CHAPTER III
CHEMISTRY OF BITUMINOUS SUBSTANCES

Bituminous substances in general may be regarded as consisting
of one or more of the following components:

(A) The Non-mineral Matrix.

(B) Associated Mineral Constituents.

Each component will be considered in turn.

(A) COMPOSITION OF NON-MINERAL MATRIX

The non-mineral matrix present in bituminous substances is a
complex mixture of hydrocarbons together with their sulfur and
nitrogen derivatives, and are frequently associated with mineral
constituents in varying amounts. The non-mineral constituents are
accordingly composed of the elements carbon and hydrogen, with
more or less sulfur, nitrogen, and at times oxygen. The constituent
hydrocarbons may either be saturated or unsaturated. Saturated
hydrocarbons are those in which the carbon valence has been com-
pletely taken up by hydrogen or other radicals, and are characterized
by their resistance to reagents (e.g. acids and alkalies) and the dif-
ficulty with which they form substitution compounds. Unsaturated
hydrocarbons are those having free carbon valences, and have the
property of forming additive compounds.

Every member of the bituminous family is a homogeneous or
heterogeneous mixture, consisting of a multitude of chemical sub-
stances, each having a definite molecular composition. These con-
stituent substances may be associated as a simple solution of liquids
in liquids, or solids in liquids; or in the form of a colloidal solution;
or as a solid solution of amorphous or crystalline solids; or as an
emulsion of immiscible liquids; or as a suspension of insoluble sub-
stances in a more or less liquid matrix; or combinations of two or

more of the foregoing phases.

66 CHEMISTRY OF BITUMINOUS SUBSTANCES III

It is contended that the characteristic dark color of asphalts is
due to the liberation of colloidal carbon under the influence of heat,
which is then adsorbed by the hydrocarbons. 1 The colloidal nature
of asphalt is confirmed by the Tyndall effect, the Brownian move-
ment observed under the ultra-microscope even in dilute solutions,
the fact that on distillation no trace of asphaltic or coal-like sub-
stances are found in the distillate, and the further fact that asphal-
tenes retain hydrogen even at 800 F.

F. J. Nellensteyn regards asphalt as a protected u lyophobe sol,"
or an extremely stable u carbon-oleosole," in the form of a "system"
consisting of three components, viz. :

(1) The "medium" (corresponding to the so-called "petro-
lenes" or "oily constituents").

(2) The "lyophilic portion" or protective bodies (correspond-
ing to the so-called "asphaltic resins").

(3) The "lyophobic portion," composed of colloidal particles
or ultra-microns of elemental carbon.

An adsorption relation exists between components (2) and (3),
forming a "disperse phase" and constituting the so-called "asphalt
micelle" (corresponding to the "asphaltenes"). According to this
hypothesis, the asphalt constituents may be classified into the fol-
lowing systems :

Petrolenes (malthenes) and oily constituents = oily medium.
Asphaltous acids plus asphaltous acid anhydrides plus asphaltic

resins = small amount of carbon with very large amount of

protective bodies.

Asphaltenes == carbon with protective bodies.
Carbenes = carbon with small amount of protective bodies.
Pyrobitumens = carbon with very little protective bodies.

The stability of the "system" depends upon the respective sur-
face tensions of the "medium" and "micelle." Changes in the sta-
bility, including "flocculative" and "peptizing" reactions, give rise to
a "reversible flocculation." If, however, the micelle itself is de-
stroyed and cannot be directly repeptized, the substance is said to
have undergone an "irreversible flocculation." The latter is caused
by chemical reactions (e.g. iodine, chlorine, etc.) ; by heat; or by
exhaustive extraction of asphaltenes with different solvents of suc-
cessively higher surface-tension. In natural asphalts associated with

Ill

(A) COMPOSITION OF NON-MINERAL MATRIX

colloidal mineral matter (e.g. Trinidad asphalt), the ultra-microns
present in the micelle consist partly of elemental carbon and partly
of inorganic material. Adding finely divided fillers to asphalt may
result in the formation of such micelles.

The properties of asphalts depend upon the concentration of the
disperse phase, its degree of subdivision, as well as the properties of
the medium. The combination of these functions leads from the
crude petroleum, through the soft and viscous asphalts, over to the
asphaltites. For the mechanism of this col-
loidal system in its transition from petro-
leum to the hard asphalts and asphaltites,
the following theory may be developed, in
which the underlying idea is clearly illus-
trated. In Fig. 24 the black points and
areas represent the "asphalt micelles," the
white points and areas the "oily medium."
In region A, the asphalt micelles are pres-
ent in such slight amount and in such a high
degree of subdivision that they exist in the
oily medium in the form of a molecularly
dispersed solution. This region corre-
sponds to the characteristics of crude petro-
leum before it is subjected to distillation
in the preparation of residual asphalt.
In the distillation process, the concen-
tration of the oily medium gradually
diminishes, and the particle size of the
dispersed phase (asphalt micelles) cor-
respondingly increases, until they assume
a dimension larger than molecular, and

FIG. 24. Formation of As-
phalts Illustrated Diagram-
matical ly.

eventually reach the
state of a colloidal dispersion. The gradual enlargement of the
micelles, or the increase in their number (through continued distil-
lation) is illustrated by regions B, C, D and E, which represent the
disperse systems of soft to moderately hard asphalts. Further re-
duction of the oily phase causes constantly greater reduction of the
distances of the micelles from one another, and accordingly leads to
the agglomeration of the asphalt micelles, as shown in region F.
We then come into the range of hard asphalts and the reversal of

68 CHEMISTRY OF BITUMINOUS SUBSTANCES III

phases. If the reduction of the oily medium continues further, then
the aggregates of the micelles become so large and their number in-
creases to a degree that they eventually fuse together, resulting in
the asphalt micelles forming the continuous phase and the oily con-
stituents the disperse phase, as illustrated in regions V, W, X and Y.
If the process continues sufficiently far, the system will finally consist
only of asphalt micelles, as shown in region Z. Regions V to Z em-
brace the hard, high fusing-point asphalts and asphaltites.

It is a comparatively simple matter to ascertain by analytical
methods the percentage by weight of the elements present. This is
termed the ultimate analysis, in contra-distiriction to the molecular
composition.

The greatest percentage of carbon found in any bituminous sub-
stance is in the case of anthracite coal, which runs as high as 98
per cent The smallest percentage is contained in certain peats,
which run as low as 50 per cent. With the exception of the non-
asphaltic pyrobitumens, carbon ranges from 85 to 95 per cent.

Hydrogen never exceeds 15 per cent. In the paraffin series of
hydrocarbons, the carbon is combined with as much hydrogen as
possible, and this accordingly contains the largest percentage of
hydrogen and the smallest percentage of carbon. The lowest mem-
ber of this series CtL, a gas, contains 75 per cent of carbon and 25
per cent of hydrogen. The member C 3 oHe2 contains 85.31 per cent
of carbon and 14.69 per cent of hydrogen. In the olefin series
CnHU, the relation of carbon to hydrogen is constant, and figures :
carbon 85.71 per cent and hydrogen 14.29 per cent.

The percentage of sulfur varies considerably. Waxes, coal tar
and coal-tar pitch, pine tar arid pine-tar pitch, hardwood tar and
hardwood-tar pitch, also fatty-acid pitch are practically free from
sulfur. In petroleum, the sulfur varies from a trace to 5 per cent
as a maximum. Mexican petroleum contains between 3 and 5 per
cent; Trinidad, Venezuela and California petroleums contain be-
tween l / 2 and 4 per cent; semi-asphaltic petroleums including the
Mid-continental and Texas oils contain from a trace to 2]/2 per cent
Paraffinaceous petroleums contain merely a trace. Residual oils
contain from a trace to 5 per cent. Residual asphalts, blown as-
phalts, sludge asphalts, native asphalts, asphaltites, asphaltic pyro-
bitumens and non-asphaltic pyrobitumens contain from a trace to ifr

Ill (A) COMPOSITION OF NON-MINERAL MATRIX 69

per cent sulfur. Tars and pitches derived from non-asphaltic pyro-
bitumens contain from a trace to I J4 per cent

Nitrogen is rarely present in excess of 2 per cent. Mineral
waxes are free from nitrogen. Petroleum asphalt, asphaltites and
pyrobitumens contain from a trace to 1.7 per cent nitrogen. Tars
and pitches contain from o to I per cent.

Oxygen rarely exceeds 5 per cent, except in the case of non-
asphaltic pyrobitumens which contain up to 45 per cent of oxygen.

At the present time but a comparatively small number of dis-
tinct chemical substances have been identified in bituminous com-
plexes. A vast amount of research work must yet be accomplished.
Although hundreds of substances of definite molecular composition
have been identified in petroleums, native mineral waxes, pyrogenous
waxes and certain tars, comparatively little is known regarding the
innumerable non-mineral molecular substances present in native as-
phalts, asphaltites, asphaltic pyrobitumens, non-asphaltic pyrobitu-
mens, pyrogenous asphalts and pitches.

The chemistry of bituminous substances is further complicated
by the fact that commercial specimens of any given material are
rarely alike in composition. In some, certain chemical bodies pre-
dominate ; in others, they may be present in smaller amounts ; while
in still others they may be absent. Thus two shipments of any
given member of the bituminous family are apt to fluctuate widely
in composition and physical properties, even when emanating from
the same source. Again, a native bituminous substance derived
from a single deposit will often vary, depending upon the degree of
exposure and extent of metamorphosis. Native bituminous sub-
stances are in a constant state of transition, as the result of their
age and environment. Pyrogenous bituminous substances show a
marked variation in composition and physical properties, depending
upon the raw materials used in their production and the exact con-
ditions to which they have been subjected in their processes of manu-
facture, including the temperature, length of treatment, etc. Bitu-
minous substances should not therefore be compared with vegetable
or animal fats or oils, which in the case of any given material will
run fairly uniform in composition and physical properties.

In certain instances, comparatively simple tests have been de-
vised for identifying single chemical bodies present, whereas in other

70 CHEM1STR? OF BITUMINOUS SUBSTANCES III

cases the ultimate analysis of the material will furnish a clue to the
identity of the substance under examination.

Various methods have been proposed to separate bituminous
substances into their constituents, including fractional distillation
under reduced pressure, 2 the selective action of solvents, 3 the use of
adsorption media, 4 and combinations of the foregoing.

(B) COMPOSITION OF ASSOCIATED MINERAL CONSTITUENTS

The mineral constituents may be present in one or more of the
following typical forms :

1. As consolidated mineral particles consisting of a porous rock
impregnated with the bituminous constituents. This type is exem-
plified by the so-called u rock asphalts," which are usually composed
of a fine-grained limestone or sandstone matrix, carrying the asphalt
in its voids.

2. As unconsolidated mineral particles admixed mechanically
with the bituminous constituents. This is typified by the numerous
deposits of impure native asphalts and asphaltites, in which the
bituminous constituents are associated with more or less detritus
derived from the surrounding soil ; also blast-furnace tar and pitch
which carry a proportion of mineral dust carried over mechanically
by the furnace gases as well as metallic compounds which result from
the corrosion of pipe lines and containers used in storage and

transport.

The principal unconsolidated mineral constituents present in na-
tive asphalts and asphaltites consist of calcium carbonate, magnesium
carbonate, calcium sulfate, dolomite, clay, silica and the various
silicates, iron sulfide, etc.

3. As colloidal mineral particles held in suspension by the bitu-
minous constituents. Trinidad Lake asphalt is typical of this group,
and is characterized by the presence of colloidal clay and silica
which are not removable by filtration and are^ readily discernible
when viewed under an ultra-microscope. 5 Richardson makes a
special virtue of the fact that refined Trinidad asphalt contains nat-
urally about 27 per cent filler composed largely of "colloidal"
particles.

4. As mineral matter held in chemical combination by the non-
mineral (i.e., pure bituminous) constituents. This group differs
from the foregoing, inasmuch as it relates to a chemical union of the
mineral and non-mineral components. Many native asphalts carry
small percentages of iron and aluminium, but it is as yet a mooted
question whether these are present as colloidal particles, or united

Ill (C) ASSOCIATED NON-MINERAL CONSTITUENTS 71

chemically with the bituminous matter. Most residual and blown
petroleum asphalts contain a trace of iron, derived from the stills in
which they are refined. Fatty-acid pitch, wood-tar pitch, bone-tar
pitch and rosin pitch carry a substantial amount of iron or copper,
depending upon whether they have been produced in an iron or
copper still. Sludge asphalts bear a trace of combined lead derived
from the lead containers in which they have been treated.

Rare elements are also normally associated with certain native
asphalts and asphaltites. Thus the following proportions of nickel,
expressed in parts per million, have been reported : 6 Trinidad as-
phalt 194, Swiss asphalt 120, gilsonite 133, residual asphalt from
U. S. petroleum 240, crude U. S. petroleums i to 93 parts, ozokerite
trace to nil. Vanadium is present in most varieties of petroleum and
asphalt, 7 and has also been reported in Argentine grahamite 8 and
Peruvian impsonite. 9 Vanadium occurs in the more asphaltic crudes,
but is not present in any quantity in non-asphaltic (i.e., paraffin-
aceous) crudes. A high vanadium content is generally associated
with a high nickel content. 10 Uranium has similarly been reported
in glance pitch found in Utah, 11 and molybdenum in asphaltic petro-
leum 12 and Holzheim (Swabian) oil shales.

Native asphalts often contain non-mineral impurities in the form
of decayed vegetable substances of peat-like nature, which were
originally present in the soil, now associated with the asphalt. These
substances are derivatives of humic, or ulmic, crenic, etc., acids.

Certain tars and pitches as well as residual asphalts, which have
been overheated in their process of manufacture, will carry variable
amounts of so-called u free carbon." This in reality consists of
hydrocarbon derivatives, polymerized under the influence of heat
to an insoluble modification, similar in certain respects to bitumi-
nous coal. It is probable that the "free carbon" may under certain
conditions consist in part of amorphous carbon, similar to lamp-
black. R. Hodurek has demonstrated that tars inherently contain
certain insoluble constituents which may be removed by filtration
(which he designates "Carbon I") and that other substances ("Car-
bon II") are formed by precipitation upon dissolving the tar in
solvents, the quantity being dependent upon the particular solvent
employed. 14

72 CHEMISTRY OF BITUMINOUS SUBSTANCES III

(D) BEHAVIOR WITH SOLVENTS

This question will be taken up in detail in Chapter XXVI.
(E) BEHAVIOR ON SUBJECTING TO HEAT

On heating bitumens, the following reactions take place : at low
temperatures they commence to distil without decomposition. Con-
tinued heating causes a rapid change in penetration and viscosity
during the first few days or weeks, whereas the flash-point is least
affected. The fusing-point changes regularly but markedly. There
is a general decrease in acidity (i.e., acid value) which finally attains
a constant figure. 16 As the temperature increases, a certain amount
of cracking takes place, resulting in the depolymerization of both the
distillate and residue. At still higher temperatures, the distillate
continues to deploymerize, whereas the residue commences to polym-
erize with the formation of asphalt-like bodies. Beyond this, the
residue again undergoes depolymerization with the evolution of a
certain amount of fixed gases, likewise the formation of carbenes,
free carbon, and eventually elemental carbon. Thus in the case of
non-asphaltic and semi-asphaltic petroleums, polymerization takes
place when the residue in the still reaches 600 to 800 F., whereby
asphalt-like substances are produced. In other words the percentage
of asphalt in petroleum is actually increased under these conditions.
Beyond this temperature, cracking takes place, in which the asphalt
is destructively distilled and decomposed into simpler molecules,
yielding gases, liquid distillates and a residue of coke. 16

The asphaltic pyrobitumens behave differently. When heated
to between 600 and 800 F., they undergo "cracking." This is in
reality a form of depolymerization in which complex molecules are
broken down into simpler ones. As a result, the original substance,
which is practically insoluble in organic solvents, increases materially
in! solubility. Elaterite and wurtzilite depolymerize and become
completely soluble in benzol and carbon disulfide. Albertite is more
difficult to depolymerize than elaterite or wurtzilite, requiring a
higher temperature and an increased time of treatment. On the
other hand, impsonite depolymerizes only slightly under these con-
ditions. If heated to higher temperatures, the asphaltic pyrobitu-
mens suffer destructive distillation, leaving a residue of coke. The
depolymerization is similar to the action which takes place on melt-

Ill

(E) BEHAVIOR ON SUBJECTING TO HEAT

ing fossil resins, such as copal, amber, etc., in manufacturing varnish.
A schematic outline of what occurs upon subjecting bitumens and
pyrobitumens to heat is given in the following tabulation :

TABLE IV
BEHAVIOR ON SUBJECTING TO HEAT

Heated
under 300 C.

Heated
300-450 C.

Heated
450-700 C.

Heated
700-1500 C.

Non-asphaltic

Distil and the

Residues de-

petroleums

residues fuse

polymerize

slightly

S e mi- asphalt! c

Distil and the

Residues poly-

and asphaltic

residues fuse

merize, form-

petroleums

ing asphalt-

like bodies

Depolymerize,

Bitumens

Mineral waxes

Small amount

Depolymerize

yielding as

distils with

and distil

distillate

slight decom-

mostly open-

position, and

chain hy-

the residues

drocarbons

fuse

and a resi-

Asphalts and

Fuse

Distil more or

due of coke

Asphaltites

less

Asphaltic pyro-

Infusible and

Depolymerize

bitumens

insoluble

and become

Pyrobitumens. . '

Non-asphaltic

Infusible

more soluble
Unaffected

Depolymerize

Depolymerize,

pyrobitumens

slightly and

yielding as

distil

distillate,

mostly cyclic

hydrocarbons

and a residue

of coke

F. J. Nellensteyn has proposed the following theory to account
for the formation of asphalts and the like:

(/) Formation of Asphalts:
Hydrocarbons {$$* } =

Transformed to carbon + Adsorbed protective hydrocarbon bodies

Asphaltenes

(//) Behavior of the Asphaltenes:

Asphaltenes

extracted

oxidized

heated

74 CHEMISTRY OF BITUMINOUS SUBSTANCES III

Carbon + Small amount of adsorbed protective hydrocarbon bodies

Free carbon

Free carbon { heated } =

Carbon + Very small amount of adsorbed hydrocarbon bodies

Retort carbon

Resulting in a further decomposition of the protective bodies.

(///) Synthesis of Asphaltenes:
Retort carbon {electrically atomized in the presence
of protective hydrocarbon bodies } =

Carbon + Adsorbed protective hydrocarbons
Asphaltenes

(F) REACTIONS WITH GASES

(a) Oxygenation. On blowing air through bituminous sub-
stances at fairly high temperatures, hydrogen is removed in the form
of water, and at the same time the hydrocarbons polymerize, form-
ing bodies of higher molecular weight and more complex structure.
The reaction may be roughly represented as follows :

CxH y + O = CxHy_ 2 + H 2 O

Analysis shows that little or no oxygen actually combines with
the asphalt. 17 One theory is that polyhydric compounds acidic in
character, are formed during the intermediate stage of oxidation,
which upon further heating change to anhydrides similar to the poly-
naphthenic acids, with progressive condensation and polymerization.
Various bituminous substances are affected differently by the blowing
process. Asphalts present in petroleum are readily converted into,
tough, rubber-like products having a higher fusing-point and much
more resistant to temperature changes. Fatty-acid pitch behaves in
a similar manner. Natural asphalts are affected very much less,
and pitches derived from coal and wood are scarcely affected at all.
Even the petroleum asphalts themselves are affected differently, de-
pending upon their origin and chemical characteristics. This sub-
ject will be gone into more fully under the heading 44 Petroleum
Asphalts."

(b) Hydrogenation. This is carried out by heating bituminous
substances (e.g., coal, asphalt, paraffin wax, tars, etc.) with hydro-

Ill (F) REACTIONS WITH GASES 75

gen in an autoclave at high pressures (100 to 200 atmospheres) at
400 to 450 C. The process was discovered by Friedrich Bergius, 18
and has been termed "berginization." The following changes take
place :

1 i ) Thermal decomposition, i.e., cracking.

(2) Hydrogenation, whereby the unsaturated hydrocarbons re-
sulting from the thermal decomposition, at their moment of forma-
tion, react with the hydrogen, producing saturated hydrocarbons of
lower boiling-points.

The process differs from straight thermal decomposition in the
following respects: extensive polymerization is avoided and the
deposition of carbonaceous matter is almost entirely prevented,
moreover, as the reaction proceeds the pressure in the autoclave
falls, due to the absorption of hydrogen, whereas in the absence of
hydrogen, the pressure would increase due to the formation of fixed
gases. Finally, the end product consists largely of saturated hydro-
carbons, whereas in the cracking processes, unsaturated bodies will
predominate. The resulting products are characterized by a higher
hydrogen content. Any oxygen present in the original material is
converted into water, and any nitrogen into ammonia.

In treating petroleum by the Bergius hydrogenation process, hy-
drogen gas is introduced at a pressure of about 3600 Ibs. per sq. in.
in the presence of a catalyst. Molybdic anhydride and sulfur 19
seems to be most favored, although numerous othef catalyzers have
been proposed, including chromium, tungsten, uranium, manganese,
cobalt, etc., compounds, also metallic iron or nickel. 20 The catalyst
should be sulfur-resistant and serve to speed up the reaction and
eliminate the oxygen from the hydrogenated product. Relatively
impure hydrogen, containing hydrogen sulfide, is used, produced
from coal or coke by the water-gas process.

Asphaltic crudes of all characters (e.g., Venezuelan, Panuco, Co-
lombian, etc.), likewise residues from refinery crudes, as well as
cracking-plant tars, may be converted into volatile distillates, free
from asphalt and low in sulfur, with volumetric yields somewhat in
excess of 100% (although the specific gravity of the product is
usually less than the crude stock). Dark asphaltic constituents are
converted into practically colorless hydrocarbons of the gasoline
range. In other words, the hydrogen will combine with the colloidal

CHEMISTRY OF BITUMINOUS SUBSTANCES

III

carbon present in the asphalt present. In actual practice, the petro-
leum is first topped to remove all the gasoline present. From mixed-
base crudes, highly paraffinic products may be produced, such as
gas-oils, burning oils and high-grade lubricants. From paraffin
crudes, so-called aromatic products may be produced, as for example,
a highly anti-knock gasoline. No coke is produced in the process.

The charging stock, together with sufficient hydrogen, is pumped
through heat-exchangers to a coil-furnace, and thence into the reac-
tion vessel containing the catalyst where it is subjected to the re-
quired temperature and pressure. Units have been installed capable
of treating 5000 barrels of crude daily. 21 The final products with
the gases pass through heat-exchangers and coolers to a high-pres-
sure separator, where the liquid reaction products are separated
from the unconsumed hydrogen and other gases, which latter are
scrubbed with oil under pressure to remove the hydrogen sulfide,
and the purified gas used over again.

The following five adaptations of hydrogenation appear to be of
most importance in petroleum refining: 22

TABLE V

APPROXIMATE VOLUMETRIC

YIELD or

TOTAL

GAS

PROCESS

CHARGING STOCK

PRIMARY RESUI-T

VOLU-

FORMA-

Gasoline

Burn-
ing Oil

Gas
Oil

Lube
Oil

METRIC
YIELD

TION

%byvt.

High-sulfur, asphalt-

Asphalt and sulfur elimination

ic heavy residue

with simultaneous conversion

entire charge into distillate

oils

. . .

zoz

2 to 3

Low-grade lube dis-

Production premium lube, par-

tillate

ticularly as regards temper-

ature-viscosity relationship,

flash, carbon, and gravity

....

Z04

0.5 to z,s

Low-grade burning

Production of low-sulfur pre-

oil distillate

mium grade burning oil

zo3

O-S tO 2

Cracked naphtha

Desulfurization and gum sta-

bilization without deteriora-

tion in yield and knock rating

characteristic of acid treating

zoo

....

. . .

zoo

0.5

Paraffinic gas oil

Production of low-sulfur, low-

gum, good antiknock gasoline

65 to zoo

70 to zoo

S to 35

If the charging stock is paraffinic in character, it is heated to
750 F., and if aromatic, to 1000 F. The reaction is exothermic. 23
It is' advocated that very heavy asphaltic crudes be treated in three

Ill () REACTIONS WITH ACIDS 77

stages, at pressures of 1000, 200 and 20 atmospheres, respectively* 04 ,
The residual product obtained from the hydrogenation of residual
asphalts has characteristics somewhat similar to those of blown pe-
troleum asphalt. 25 Partial hydrogenation of petroleum stocks at
900 to 950 F., without using a catalyst, is claimed to result in the
precipitation of any asphalt present 26 Low-temperature coal-tar
(topped to 200 C.), when hydrogenated with a mixture of molybdic
acid and sulfur as catalyst, under an initial pressure of 145 atmos-
pheres, yielded 99.2% of hydrogenated oil. The reaction started
at 200 C., which increases to a maximum of 360 C. 27 The prod-
uct is free from tar acids and pitchy matters. 28 Cdke-oven tar
showed an increase in volatile products below 300 C. from 31.7
to 65.5%, and in this case the hydrogen was absorbed by the liquid
residue as well as by the fixed gases. Paraffin wax was entirely con-
verted into liquid and gaseous products. Similarly, Alberta san^
asphalt has been hydrogenated under a pressure of 1470 Ibs. at
380 to 410 C. in the presence of ammonium molybdate and alumi-
num chloride, or NiCOs and Fe2O 8 or CaO (to remove the sulfur),
being converted into 80 to 90% by weight of oils based on the as-?
phalt present in the raw material, and involving the absorption of

by weight of hydrogen. 29

A modification of the preceding has been devised by Meilach
Melamid, which consists in atomizing asphaltic petroleum into a
heated reaction chamber together with hydrogen, so that the two
are brought in contact with a catalyzer (e.g., tin or bismuth alloys
melting below 700 F.)- 80 In this process the hydrogenation and
continuous distillation of the crude oil take place simultaneously.
In the case of a Panuco (Mexican) crude, the distillate to 320 C.
was increased from 19 to 26 per cent, and in the case of a brown-*
coal tar resulting from the Mond gas process, the pitch residue was!
reduced from 46.8 per cent to o.o per cent, with a corresponding
increase in the percentages of distillates.

(G) REACTIONS WITH ACIDS

(a) Liquid Sulfur Dioxide* This agent has the property of
dissolving unsaturated hydrocarbons ait low temperatures ( 7 to
11 F.), whereas the saturated hydrocarbons remain substan-

78 CHEMISTRY OF BITUMINOUS SUBSTANCES III

tially insoluble. Advantage is taken of this fact in certain commer-
cial refining operations, also in the laboratory examination of bitu-
minous substances. 81 In general, the higher boiling-point paraffins,
naphthenes and naphthenic acids (i.e., over 175 C.) are insoluble,
whereas the aromatics and the true unsaturated hydrocarbons (con-
taining two or more double bonds) are miscible with liquid sulfur
dioxide in all proportions. Sulfur and its organic combinations,
nitrogen compounds, resinous and asphaltic substances are also sol-
uble, though their solubilities decrease with increasing complexity of
the molecule. 82

(b) Sulfuric Acid and Sulfur Trioxide. Concentrated sulfuric
acid, or a mixture of concentrated sulfuric acid with sulfur trioxide
reacts with bituminous substances in a somewhat complicated man-
ner, involving both the formation of sulfo derivatives and that of
simple solution, accompanied by a certain amount of polymeriza-
tion. In general, it may be stated that the following classes of
substances are removed by concentrated sulfuric acid: unsaturated
and aromatic hydrocarbons, asphaltic bodies, saponifiable constitu-
ents and alkaline bases. This reaction forms the basis of the method
used commercially for refining petroleum distillates and is likewise
used in the laboratory under accurately controlled conditions for
the separation of saturated and unsaturated hydrocarbons. (See
Test 34.) A process has been described which consists in heating
residual asphalt with 20 to 25 per cent of concentrated sulfuric
acid to 120 C. which is then gradually increased to 240 C. The
addition compounds are separated and the residue (i.e., sludge as-
phalt) used for molding purposes. 33

(c) Nitric Acid. Strong nitric acid reacts in two ways, namely
in the formation of nitro derivatives and in the oxidation of the
hydrocarbons. Which of these predominates depends upon the
nature of the hydrocarbons, the strength of the acid, the tempera-
ture, etc. Although much work has been done in investigating the
character of end-products, but little commercial use has been made
of this reaction. 84 Similar products are obtained by heating tars,
pitches or asphalt with substances containing NOa or NOs radicals. 35
It has been noted that certain of the nitro addition products are
soluble in acetone and alcohol, thus differing from the hydrocarbons
from which they were derived.

Ill (/) REACTIONS WITH METALLOIDS 71)

(d) Sulfuric Acid and Formaldehyde. Formaldehyde in the
presence of concentrated sulfuric acid reacts with unsaturated cyclic
hydrocarbons and asphaltic constituents with the formation of an
insoluble formolite, whereas the other classes of bodies remain
unaffected. This reaction is utilized in the laboratory examination
of bituminous substances. (See Test 35.) It has also been pro-
posed to incorporate the formolite with asphalts, pitches, etc., to
produce molded products, electrical insulation, etc. 86

(e) Phosphoric Acid. Phosphoric acid has been proposed for
refining mineral oils, yielding "sludge asphalt"

(H) REACTION WITH ALKALIES

Strong alkalies react with the saponifiable constituents present,
including the following groups of substances : free asphaltous acids,
asphaltous acid anhydrides, fatty and resinous constituents. The
saponifiable constituents in commercial bituminous substances vary
from a trace in the case of bitumens and asphaltic pyrobitumens,
to as high as 90 per cent and over in the case of rosin pitch and
fatty-acid pitch. The effects of alkalies will be considered later in
greater detail.

(I) REACTIONS WITH METALLOIDS

(a) Sulfur and Sulfur Bichloride. Under the influence of
heat, sulfur has the same condensing effect upon bituminous sub-
stances as oxygen, since it results in the removal of hydrogen, but
in this instance in the form of gaseous hydrogen sulfide. The reac-
tion may roughly be represented as follows :

CxHy + S = CxHy-2 + H 2 S

A certain amount of polymerization also takes place, and where the
sulfur is used in excess, it is likely that a certain amount remains in
combination with the bituminous substances in the form of addition
products. The process has been termed "vulcanization," and is
used to improve the stability of bituminous mixtures. This will be
:onsidered more fully under the description of the respective sub-
stances in subsequent chapters.

Sulfur dichloride combines with bituminous substances under

&) CHEMISTRY Of BITUMINOUS SUBSTANCES III

moderate heat, with the liberation of hydrochloric acid as a product
of the reaction, Which may be roughly indicated by the following:

= GH y _ 6 + 2H*S + 2HC1

. 38

This reaction is merely of academic interest 3

(b) Selenium. Selenium combines with asphalts, etc., at 160 to
300 C. in a manner analogous to sulfur, with the liberation of
hydrogen selenide, a proportion of the selenium remaining in com-
bination with the residue. 30

(c) Phosphorus. It has been noted that phosphorus, or PgOs
under the influence of moderate heat, will cause asphalts to polym-
erize, and in part combine chemically with the asphalt, resulting
in an increase of hardness, fusing-point and stability. 40

(d) Halogens. Chlorine and iodine 41 eliminate hydrogen and
result in the deposition of carbon, in accordance with the following
reactions :

C*H y + Cl = CxH y ^ + HC1

y + Cl = .C.-iH y -i + C + HC1

Similar reactions take place with iodine, also boron fluoride. 42
The relation between the "iodine number" of asphalts and their
structure has also been investigated. 43

, Halogens seem to destroy the protective colloids that keep the
colloidal carbon in suspension and result in the deposition of ele-
mental carbon, if the reaction progresses far enough. Upon treat-
ing asphalt with chlorine gas in the presence of a trace of iodine at
200 to 250 C., the fusing-point is increased materially, and a hard,
glossy product is obtained having a glossy fracture. 44 Similarly, a
soft coal-tar pitch will have its fusing-point increased from 25 or
30 F. ,to 120 F,, 45 likewise its adhesiveness increased. 4 * It i$
claimed that hexachlorethane will react in a similar manner. 47 A
process has also been proposed which involves treatment with
chlorine below 130 C. in the presence of antimony chloride, phos-
phorus chloride, or iodine; 48 likewise a method of treating with con-
centrated sulfuric acid, followed by FeCU, AlCls, or PCls. 49

Ill (/) REACTIONS WITH METALLIC SALTS 81

(J) REACTIONS WITH METALLIC SALTS

Bituminous substances act as "dispersoids," in that they have
the property of dispersing colloidal solids, including certain metal-
lic salts. Trinidad asphalt is a typical example, in which the asphalt
acts as a dispersoid for adventitious mineral matter of colloidal
nature, consisting principally of colloidal clay. That the clay is
present in a colloidal state is evidenced by the following facts : ( i )
a dilute solution of Trinidad asphalt in carbon disulfide, upon stand-
ing, retains indefinitely the clay in suspension, and moreover it
cannot be separated upon centrifuging, or upon passing the solution
through an ultra-filter; and (2) an examination of the solution
through the ultra-microscope shows the mineral particles to be in a
characteristic state of active motion, known as Brownian movement
or "pedesis," which may be made to cease under the influence of an
electric field ("cataphoresis"). This subject will be discussed fur-
ther in Chapter XXIV under the heading "Colloidal Particles
Liberated 'In Situ'." Other metallic salts which will disperse in
bituminous substances include sulfates and selenates, chlorides, ox-
ides, acetates and borates.

CHAPTER IV

GEOLOGY AND ORIGIN OF BITUMENS AND
PYROBITUMENS

GEOLOGY

Age of the Geological Formations. The earth's crust has been
divided into natural groups or strata in the order of their antiquity.
There are five main divisions, which range in sequence as follows :

1. Quaternary or Post-tertiary, representing the strata now in
the process of formation.

2. Tertiary or Caenozoic, embracing the age of recent life.

3. Secondary or Mesozoic, representing the less recent life.

4. Primary or Paleozoic, representing the so-called "ancient
life."

5. Archaean or Azoic, representing the so-called lifeless strata.

These divisions are recognized by the distinctive organic re-
mains, fossils, minerals and other characteristics. They are clas-
sified into various "systems" as shown in Table VI.

The systems form a chronological time-chart indicating the rela-
tive ages of the earth's strata. The systems are further sub-divided
into groups which differ in different localities, but it will be unneces-
sary to consider their sub-classification here.

Petroleum occurs in all of the geological horizons from the Re-
cent down to the Pre-Cambrian. Certain systems are richer than
others, especially the Pliocene, Miocene, Oligocene, Eocene, Car-
boniferous, Upper Devonian and Lower Silurian (Ordovician).
Asphalts, asphaltites and non-asphaltic pyrobitumens are found in
all the systems from the Pliocene to the Silurian. Mineral waxes
are found largely in the Pliocene, Miocene, Oligocene, Eocene and
Cretaceous.

The non-asphaltic pyrobitumens do not occur in the older Paleo-
zoic formations i.e., the Silurian or Cambrian Systems). The
Carboniferous System contains the most valuable coal deposits; the
Permian and Triassic Systems contain coals of inferior quality, and

CHARACTER OF THE ASSOCIATED MINERALS

the coals found in the Jurassic, Cretaceous, Eocene and Oligocene
Series are still more inferior in quality. Lignite occurs in the Oligo-
cene and Miocene Series, and peat in the Pliocene and Pleistocene.
The Pre-Cambrian Series consists largely of crystalline, metamor-
phic rocks of volcanic and igneous origin. The non-asphaltic pyro-
bitumens, as might be expected, do not occur in rocks of this char-
acter. Graphite, however, occurs in the Pre-Cambrian rocks, and
may possibly have been derived from vegetable matter, although no
signs of associated plant remains have been found in these rocks.

ERA

Quaternary or Post-
tertiary

Tertiary or Caenozoic. .

Secondary or Mesozoic.

TABLE VI

SYSTEM

f f Historic ^

I Recent or Post-glacial \ Prehistoric
,.1 I Neolithic

[ Pleistocene or Glacial

f Pliocene
I Miocene
' ' I Oligocene
I Eocene

Cretaceous . . .

r Upper
Middle

Lower

Jurassic

Middle

Lower

Triassic

Permian

Carboniferous <

Swer

Primary or Paleozoic.

Devonian

Silurian

Cambrian. .

f Upper
| Middle
[ Lower

/Upper

\ Lower (Ordovician)

f Upper
| Middle
[Lower

Archaean or Azoic Pre-Cambrian

The particular geological system is of value in enabling us to
prospect and trace deposits of bitumens and pyrobitumens in any
given locality.

Character of the Associated Minerals. Bitumens and pyrobitu-
mens, with but few exceptions, are found in sedimentary deposits of
sand, sandstone, limestone and sometimes in shale and clay. Rare

84 GEOLOGY AND ORIGIN Of BITUMENS AND PYROBITUMENS IV

occurrences have been reported in igneous 'rocks, but then only in
very small quantities.

Modes of Occur .ence. Bitumens and pyrobitumens are found in
nature in the f oP : wing ways :

1. Over flews:

(a) Springs.

(b) Lakes.

2. Impregnating Rocks:

(a) Subterranean pools or reservoirs.

(b) Horizontal rock strata.

3. Filling Veins:

( a ) Caused by vertical cleavage.

[b ) Caused by upturning.

c) Caused by sliding.

d) Formed by sedimentation.

Springs. Petroleu;n and the liquid forms of asphalt only are
found in springs (Fig. 25). These emanate from a fissure, crevice,
or fault which permits the petroleum or liquid asphalt to rise to the
surface from some depth. Petroleum or asphalt springs have been
reported in various parts of the world, but are rarely of commercial
importance. tl

Lakes. Asphalt only is sometime^ found in lakes, which are in
reality springs on a very large scale (Fig. 26). Some of the largest
and most valuable deposits occur in this form, the best known being
the lakes at Trinidad and Venezuela. It is probable that the as-
phalt is forced up from below in a liquid or semi-liquid condition
by the pressure of the o\\ and gas underneath, which causes it to
flow through a fissure ,or fault and spread over a large area at the
surface. Lake asphalts are moderately soft where they emanate,
but harden on exposure to the elements.

Seepage. These occur in the case of petroleum or liquid
asphalts, and usually from cliffs or mountains bearing impregnated
rock. Elmer the pressure of the material itself or the heat of the
sufi causes ^'certain quantity, Usually not very large, to flow out of
the rock and rtin towards the lower level (Fig. 27). Seepages are
ofteft found where d ripidly flowing stream of water cuts its way

MODES OF OCCURRENCE

Spring
FIG. 25

FIG. 26

Miles

Cap Rock (Shale)
Oik Oasj 0/'/\

\ " --

Seepages
FIG. 27

Subteranean J?ool or Reservoir
FIG. 28

Impregnated^Hprlzontat Strata
FIG. 29

Impregnated, Strata in. Thrust,
FIG. 30

Fault Filling caused l?y Cleavage
FIG. 31

Fault Filling caused by Upturning
FIG. 32

Vein Filling caused by Sliding of Strata Veins formect by Sedimentation
FIG. 33 FIG. 34

-JL.-1

Pure Rock Alluvium Sand Sand Limestone Clay Shale Orartift
Asphalt Asphalt Stone

1 FIGS. 25-34,

86 GEOLOGY AND ORIGIN OF BITUMENS AND PYROBITUMENS IV

through strata of rock impregnated with petroleum or asphalt
From a commercial standpoint, seepages of asphalt or petroleum
are of little value.

Subterranean Pools or Reservoirs. Practically all deposits of
petroleum of any magnitude occur below the surface of the earth in
subterranean "pools" or "reservoirs." These consist of porous
sand, sandstone, limestone (or dolomite) with a more or less imper-
vious rock cover. The porous bed is exemplified by coarse-grained
sandstone, conglomerate, or limestone. The limestone may have
been dense as it existed originally, but rendered porous in the course
o time by conversion into dolomite, with the consequent production
of voids due to shrinkage, since dolomite occupies less space than
the original limestone. The petroleum is carried in the interstices
of the porous rock and prevented from volatilizing or escaping by
an impervious cover known as the "cap-rock," usually composed of
shale or a dense limestone. The main supplies of petroleum have
been obtained from regions which have been comparatively undis-
turbed by terrestrial movements. In such cases the accumulation
of petroleum underneath forms what is known as a "pool" or "res-
ervoir" (Fig. 28). *

Impregnated Rock in Strata. Liquid to semi-liquid asphalts
occur in this manner. Rocks impregnated with asphalt are pro-
duced in two ways, viz. :

1 i ) By the gradual evaporation and hardening of an asphaltic
petroleum due perhaps to the disturbing or removal of the cap-rock,
leaving the asphalt residue filling the interstices of the stratum car-
rying it. These are usually found in horizontal strata (Fig. 29).

(2) By the liquid asphalt being forced upward under pressure,
or drawn upward by capillarity from underlying strata into a porous
rock layer above it. These are usually found in the region of a
"thrust" or upturning of the earth's strata (Fig. 30).

Filling Feins. The harder asphalts, asphaltites and asphaltic
pyrobitumens are most commonly found filling fissures in a more or
less vertical direction, caused by "faulting." In geology, a "fault"
is a more or less vertical crack in the earth's surface brought about
by the contraction and uneven settling of the strata. This is occa-
sioned by a greater movement in the rock on one side of the fault's
plane than on the other, as illustrated in Fig. 31, or by the upturning

IV MOVEMENT OF BITUMENS IN THE EARTH'S STRATA 87

of a section of the earth's crust as shown in Fig. 32. Faults allow
the liquid or molten asphalt to force its way up from underneath
and fill the crevice. As will be described later, after the asphalt
hardens in the fault, it might in time become metamorphosized and
converted into an asphaltite or asphaltic pyrobitumen. Non-asphal-
tic pyrobitumens are never found in faults, probably because they
are incapable of softening or melting under the action of heat, either
in their original state or afterwards.

Sometimes we find the harder asphalts, asphaltites and asphaltic
pyrobitumens filling a more or less horizontal fissure or cleavage
crack, brought about by the sliding of two strata, one upon the
other. The opening between the strata becomes filled with the liquid
or melted asphalt, forced up under pressure through a crevice from
below, which then hardens, giving rise to a horizontal vein as shown
in Fig. 33.

Horizontal veins are sometimes derived from prehistoric asphalt
"lakes," perhaps similar to our present Trinidad or Venezuela lakes.
In time, these harden, and become submerged in water, due perhaps
to a movement in the level of the earth's crust. The water permits
the sedimentation of mineral matter, so that 'the lake is gradually
converted into a horizontal vein. If the liquid asphalt again breaks
through a fault or fissure, it will form a superimposed vein, or per-
haps a series of such veins between sediments, as shown in Fig. 34.

In the case of non-asphaltic pyrobitumens, the veins were un-
questionably formed by a process of sedimentation. The vegetation
from which these were derived, originally grew in swampy or marshy
localities, presumably about the mouths of rivers. As the vegetation
died, it became covered with sediments of sand or clay carried down
by the water, or by calcium carbonate precipitated from the water,
which in turn formed soil for subsequent growths. These gave rise
to the future veins of non-asphaltic pyrobitumens, which are similar
structurally to the preceding (Fig. 34).

Movement of Bitumens in the Earth's Strata. It is a singular
fact that petroleum, mineral waxes, asphalts and asphaltites are not
always found in the same locality in which they originated. They
have the power of migrating from place to place, and many deposits
are still in the process of migration. A "primary deposit" is one in
which the bituminous material is still associated with the same rocks

88 GEOLOGY ANf> ORIGIN OF BITUMENS AND PYROSITUMENS IV

in which it originated, A "secondary deposit'' is one to which the
material has subsequently migrated. Bitumens usually migrate
while in a liquid or melted condition, although in certain rare in-
stances the migration has been induced by the action of flowing
water while the bitumen is in the solid state.

The main causes for the movement of native bituminous sub-
stances in the earth's surface are as follows:

1 I ) Hydrostatic Pressure, This is largely responsible for the
accumulation of petroleum in pbols or reservoirs. At some distance
below the earth's surface there is an accumulation of ground water,
the level of which wries in different localities and during different
seasons. The petroleum, being lighter than the water, floats on its
surface. As the level of the ground water varies, it will move the
petroleum about through interstices in the rock. The water tends to
push the oil ahead of it, and this will account for the accumulation
of the petroleum in the form of pools or reservoirs underneath a
cap of a dense and non-porous strata through which it cannot per-
meate. This will also explain why there is often an accumulation
of petroleum in the ground near the top of a hill or mountain. Oil
and gas are often encountered under pressure, due to the hydro-
static head of water.

Hydrostatic pressure may also cause the migration of solid as-
phalts, as for example in the case of the Dead Sea, where masses
become detached from the bottom and are caused to float upward
by the higher gravity of the water, due to the large percentage of
salt dissolved in it.

(2 ) Gas Pressure. It is probable that the action of the heat or
other forces below the surface of the earth, tend partially to va-
porize certain bitumens, so that the resulting gas will force them
into the overlying strata near the surface. In other instances the
effect of faulting, crumpling, upturning, erosion and other move-
ments of the earth's strata exposes the oil- or asphalt-bearing forma-
tions, and enables the gas pressure to force them to the surface.
Natural gas exists under great pressure in certain localities. Many
gas wells in the Baku and Pennsylvania fields have registered a pres-
sure of 600 to 800 lb., and even as high as 1000 Ib. per square inch.
This may be accounted for by the fact that as the gas is constantly
being generated, it accumulates inside of the earth's surface and
has no access to escape owing to the density of the strata above.

(3) Capillary. This force takes place m dry porous rocks
and acts on permanently liquid bitumens, of bitumens solid at ordi-
nary temperatures but transformed to the melted state by the action
of heat. Under these conditions the bitumen will' soak into the

IV ORIGIN AND METAMORPHOSIS OF BITUMENS, ETC, 89

pores of the rock or sand and gradually fill the interstices. Capil-
larity is a very much stronger force than gravity, although other
forces, such as the action of heat (see under 5) may be partly re-
sponsible. The finer the pores in the rock, the greater will be the
capillary force. Rocks saturated with moisture tend to resist the
action of capillarity, w r hich is most effective in the dry state.

(4) Gravitation. The natural weight of the overlying strata
caused by gravitation sets up a pressure where there are accumula-
tions pf petroleum or other forms of liquid bitumen underneath^
and if a fissure or fault occurs in the earth's crust, the bitumen,
being softer than the surrounding rock, will be forced to the sur-
face. Gravitation is therefore selective in its action and by exerting
a greater pull on the heavier bodies will tend to force the lighter
ones upward. Under other circumstances, where the substances
are not confined, the result of gravitation is^ to cause the petroleum
or liquid asphalt to ooze from the overlying rock matrix in the
form of "seepages."

(5 ) Effect of Heat. Heat is also a large factor in causing the
migration of bituminous substances. Its effect is variable. Undter
certain circumstances it will convert the solid bitumens into a liquid
state and thus enable them to be acted upon by the various forces
considered previously. Under other conditions, heat in the interior
of the earth will vaporize the bitumens such as petroleum and force
them upward. Again, if the heat is sufficiently intense, it is apt to
cause the bitumens to undergo destructive distillation, the distillate
condensing in the upper and cooler layers.

ORIGIN AND METAMORPHOSIS OF BITUMENS AND ASPHALTIC

PYROBITUMENS

Probable Origin of Bitumens and Asphaltic Pyrobitumens. Al-
though much has been written on this subject, no generally accept-
able conclusions have been reached. The discussion has in the main
centered about the origin of petroleum, as this is conceded to be the
mother substance, from which the other bitumens and pyrobitumens
are supposed to have been produced by a* process of metamorphosis.
The theories have been divided into two classes, namely, the inor-
ganic and the organic. We will consider these in greater detail.

Inorganic Theories. It is contended that the interior of the
earth contains free alkaline metals, presumably in a melted condi-
tion. These at high temperatures would react with carbon dioxide,
forming acetylides which in turn produce hydrocarbons of the acety-
lene series upon coming in contact with water* The acetylenes being

90 GEOLOGY AND ORIGIN OF BITUMENS AND PYROBITUMENS IV

unsaturated would have a tendency to combine with free hydrogen
and give rise to the olefine and paraffin series.

Still another theory based on similar lines assumes the presence
of metal carbides, including iron carbide, some distance below the
surface of the earth. These are supposed to decompose on coming
in contact with water and produce hydrocarbons, which upon con-
densing in the cooler upper strata give rise to petroleum. This,
however, is mere speculation, for no iron carbide has ever been
found. The occurrence of hydrocarbon gases in volcanic emana-
tions has been cited to substantiate this theory.

The cosmical hypothesis is based upon the assumption that hy-
drocarbons were present in the atmosphere which originally sur-
rounded the earth, after it had been thrown off by the sun. These
hydrocarbons are claimed to have been formed by a direct combina-
tion of the elements carbon and hydrogen in the cosmic mass. As
the earth cooled, the hydrocarbons condensed in the earth's crust,
giving rise to deposits similar to those existing to-day. This theory
has also been connected with the carbide theories, upon the assump-
tion that at the high temperatures to which the gases must have
been subjected at the time they were thrown off by the sun, and
before they condensed, the first compounds formed were carbides,
silicides, nitrides, and the like. As oxidation would not commence
until some time later, it is assumed that these carbides would remain
locked up in the interior of the earth for geologic ages, and then
gradually give rise to hydrocarbons upon being decomposed through
the agency of water.

Vegetable Theories. It has long been known that certain hydro-
carbons result during the decay of vegetation. The hydrocarbon
methane (CH 4 ), otherwise known as "marsh gas" is produced in
this manner, but only in comparatively small amounts. Similarly,
methane has been detected in the gases resulting during the decay
of seaweed.

It has been shown by others that under certain conditions hydro-
carbons may be produced artificially by the fermentation and decay
of certain forms, of cellulose, including woody fiber. Still other
scientists maintain that petroleum is produced by microscopic plants
known as diatoms, which occur abundantly in peat beds, and certain
bogs. These organisms are found to contain minute globules of

IV ORIGIN AND METAMORPHOSIS OF BITUMENS, ETC. 91

oily matter distributed in the plasma, and moreover, a waxy sub-
stance resembling ozokerite may be extracted by solvents from the
diatomaceous peat. It is contended that this oil will in time and
under pressure become converted into liquid petroleum, and at
higher temperatures and pressures possibly into asphalt. In sup-
port of this hypothesis a bed of peat has been described near Stettin,
Germany, consisting largely of diatoms and from which hydro-
carbons have been extracted in quantities up to 4 per cent.

Another theory based on similar lines infers that petroleum is
derived from a slimy substance rich in organic matter known as
"sapropel," composed largely of algae, which accumulates at the
bottom of stagnant waters. This slime becomes covered with sedi-
ments which through the agency of moisture, time and pressure, is
assumed to give rise to petroleum, and under certain conditions, to
asphalt It is of interest to note that petroleum and asphalt have
been produced in the laboratory by the hydrolysis of algae in acid
solutions. 1

In a similar manner, bitumens are claimed to have been formed
from deposits of vegetable matter, including various marine plants,
seaweeds, etc., which accumulate at the bottom of the ocean. Just
as the non-asphaltic pyrobitumens (e.g., coal) are produced by the
decomposition of terrestrial vegetation, it is contended that bitumens
have arisen from the decay of marine plants. This theory has a
number of adherents. The optical activity of certain petroleums h^s
been cited to substantiate the contention, since oils derived from
organic matter can only possess this property. It has been proven
that hydrocarbons produced from inorganic substances, such as
metal carbides, do not exhibit optical activity.

Still another theory, advocating the vegetable origin of petro-
leum, assumes its derivation from peat, lignite or coal, which have
been subjected to a sufficiently high temperature to undergo a prqc-
ess of destructive distillation, resulting in the production of liquid
and gaseous hydrocarbons. This is supposed to have occurred at
great depths below the earth's surface and the hydrocarbons con-
densed in upper layers.

The asphaltic pyrobituminous shales are similarly claimed to
have generated petroleum under the action of heat, based on the
well-known fact that when these shales are distilled commercially,

92 GEOLOGY AND ORIGIN OF BITUMENS AND PYROBITVMENS W

petroleum-like oils are produced. It is contended that the shales
themselves were derived from gelatinous algae whose remains are
still recognizable in certain of them with the aid of a microscope.

Animal Theories. In a similar manner, petroleum and asphalt
are supposed to have been produced from the accumulation of ani-
mal matter at the bottom of the ocean, which in time decomposed
into hydrocarbons. The presence of nitrogen in all forms of bitu-
men is cited in substantiation of its production from albuminoid
matter. The remains of molluscs and fish are present in certain
asphaltic pyrobituminous shales, including the Albert series of New
Brunswick, and in many rocks carrying petroleum and asphalt.
Deposits of the latter have been reported in Galicia, Wyoming, and
are particularly noticeable in the case of oil and asphalt deposits in
Uvalde County, Texas, and southeastern California. In Egypt,
shells are also found filled with bitumen. Others contend that the
living cells are in some manner absorbed into the pores of coral
reefs, and that these in time result in the formation of bituminous
limestone.

Substances closely resembling petroleum or bitumens have been
produced artificially by subjecting fish albumin to heat, under pres-
sure. Asphalt-like substances have been produced by heating gela-
tine, casein, calcium carbonate and magnesium carbonate in an at-
mosphere of hydrogen at 240 C under pressure of 33 atm. The
solution of the resultant product in carbon disuifide exhibited
Brownian movement and the particles were flocculated by ether. 2
Animal fats have similarly been converted into hydrocarbons boil-
ing below 300 C. The conversion of fats and albuminous sub-
stances into petroleum is said to depend upon three factors, namely,
pressure, temperature and time. The variations in the composition
of petroleum found in different localities, are accounted for by varia-
tions in one or more of these factors.

In conclusion it might be stated that probably all three theories
embody certain elements of truth. The cosmical hypothesis is sus-
tained by the fact that hydrocarbons have often been found in me-
teorites, although this supposition has been refuted. 3 The inorganic
theory/is f boi-ne out by the fact that hydrocarbons occur in volcanic
emanations.: The vegetable and animal theories in turn are sup-
ported by the presence of bitumens and pyrobitumens in rocks of

IV METAMORPHOSIS OF MINERAL WAXES, ETC. 93

sedirheritary character, often carrying vegetable and animal fossil
remains. Mabery contends that the presence of nitrogen in petro-
leum derived from all the principal oil fields, exists in the form of
tombinations which could only have had their origin in vegetable
or animal remains. 4

It is highly probable, therefore, that bitumens owe their origin
to two or more of the theories which have been discussed, and which
would account for their varying chemical composition and physical
characteristics.

Metamorphosis of Mineral Waxes, Asphalts, Asphaltites and
Asphaltic-Pyrobitumens from Petroleum. Although there seems
to be a wide difference of opinion regarding the origin of petroleum
authorities are pretty well agreed that petroleum when once formed,
is gradually converted into the other types of bitumen and pyro-
bitumens, under the influence of time, heat and pressure. This
process of transformation is known as "metamorphosis."

Several chemical processes are involved, e.g., oxidation, sulfuri-
zation, polymerization (i.e., the combination of like molecules) and
condensation (i.e., the combination of unlike molecules). Some
natural asphalts are derived through the slow evaporation of lower
boiling-point fractions from the original petroleum; others indicate
conversion by heat and pressure; still others show evidence of slow
oxidation. It is likely that a combination of these three processes
occur simultaneously. Asphalt associated with tar sands has under-
gone little change other than the loss of volatile fractions; on the
other hand, gilsonite, glance pitch and grahamite appear to be prod-
ucts of reaction and conversion, rather than products of evaporation.

It is contended that mineral matter in a finely divided form, as
for example "colloidal" clay, hastens the transformation of natural
gas or petroleum, by acting as a catalyzer. This theory is advanced
by Clifford Richardson. 5 In studying the well-known Trinidad
asphalt lake, Richardson concludes that an asphaltic petroleum
existing at a considerable depth is converted into a more solid form
of bitumen, namely asphalt, upon being thoroughly emulsified with
colloidal clay, sand and water through the medium of natural gas
at a high pressure. During the metamorphosis, hydrogen is gradu-
ally eliminated, the hydrocarbons becoming enriched in carbon, and
from a chemical standpoint more complex structurally. The changes

94 GEOLOGY AND ORIGIN OF BITUMENS AND PYROBITUMENS IV

brought about during this process may be regarded as a form of
polymerization, in which the hydrocarbon molecules become rear-
ranged into more complex molecules of higher molecular weight

The simplest hydrocarbons are present in petroleum. Those in
mineral waxes are somewhat more complex, and both the structural
complexity and the molecular weight increase in the case of asphalts
and the asphaltic pyrobitumens. There are no sharp lines of de-
marcation between the various types of bitumens or asphaltic pyro-
bitumens. Each class gradually merges into another, and specimens
will often be found on the border line, so that it is difficult to decide
to which class they actually belong.

From this viewpoint we may regard petroleums as passing in
gradual stages, uftder the influence of time, heat, pressure and cata-
lyzers into the soft native asphalts, which in turn pass into harder
native asphalts, and then into asphaltites and finally into the asphal-
tic pyrobitumens and asphaltic pyrobituminous shales. 6

TABLE VII

PETROLEUM (Crude Oil)

/ \

Non-asphaltic Petroleum Semi' Asphaltic and Asphaltic Petroleums

I I

Mineral "Waxes Native Asphalts

( Ozokerite ) / * \

Pure and Impure

Fairly Pure Asphalts (Rock Asphalts)

J I

Asphaltites (Impure Asphaltites)

I I

Asphaltic Pyrobitumens Asphaltic Pyrobituminous Shales

CELLULOSE (Woody Fiber)

Vegetable Growths (Sphagnum) in Bogs, Swamps, etc. Trees, etc*

Peat
Impure (Associated with Mineral Matter) Pure

Lignite Shales Lignite

I I

Coal Shales Bituminous Coal

Anthracite Coal
Graphite

IV ORIGIN OF NON-ASPHALTIC PYROBITUMENS 95

It is highly probable that all deposits of asphalt are produced
by metamorphosis from asphaltic petroleum. Similarly it seems
likely that all deposits of mineral wax, such as ozokerite, etc., result
from the metamorphosis of paraffinaceous petroleum.

Elaterite, wurtzilite, albertite, impsonite and the asphaltic pyro-
bituminous shales represent the final stages in the metamorphosis
of petroleum. The first four are comparatively free from mineral
matter. If the latter predominates, the product is known as an
asphaltic pyrobituminous shale. The non-mineral matter contained
in these shales has the same general characteristics as elaterite,
wurtzilite, albertite or impsonite, depending upon how far the meta-
morphosis has progressed.

Table VII gives an approximate idea of the natural metamor-
phosis of bitumens and pyrobitumens, one from another. 7

ORIGIN AND METAMORPHOSIS OF NON-ASPHALTIC
PYROBITUMENS

The origin of non-asphaltic pyrobitumens has been definitely
established. The associated fossil remains clearly prove that these
have been derived from vegetable matter containing cellulose, a
carbohydrate having the empirical formula (CeHioOs)^

The decomposition of cellulose when the air is partly or wholly
excluded, as would be the case when buried in the ground, results in
the loss of carbon dioxide, methane, and water. In this manner,
cellulose ultimately yields a series of products grouped under the
heading of non-asphaltic pyrobitumens. The conditions favorable
to their production seem to be the growth of vegetable substances
about the mouths of rivers, combined with a change in water-level.
The sediment carried down by the river, formed beds of sand or
clay which sealed the vegetation in between the strata. In this man-
ner the vegetable matter was protected from atmospheric oxidation
and at the same time probably subjected to fermentative heat, also
to a gradually increasing pressure, as successive layers accumulated.
The vegetation doubtlessly embraced many different kinds, including
trees, ferns, grasses, mosses, and the like. Fossil ferns are still
clearly evident in coal beds. In other cases carbonized trees, roots
and fibrous tissue are recognizable, and in still others, the resins
originally present in the wood are found intact. Amber and fossil

36 GEOLOGY AND ORIGIN OF BITUMENS AND PYROBITUMENS IV

copal often occur in peat, and large masses of vegetable resin have
been identified in beds of lignite and bituminous coal

Peat represents the first stage in the metamorphosis of coal from
vegetable matter, and occurs in bogs or other swampy places. Very
often on the surface of a bog or swamp we see the still living and
growing plants. A little below, we find their decayed remains, and
still deeper, a black glutinous substance saturated with moisture,
known as "peat" 8

The exact nature of the changes which take place in the trans-
formation of vegetable matter into peat is not clearly understood.
The ultimate analysis shows that the percentages of hydrogen and
oxygen have diminished, and carbon correspondingly increased. In
the most recent deposits, peat is loosely compacted, but as it accumu-
lates under the sediments, it becomes compressed. A bed which
was possibly once a foot thick might shrink to several inches. In
all probability the pressure developed by the superimposed layers,
aids in the transformation of peat into coal.

Lignite 9 or browncoal is intermediate between peat and bitumi-
nous coal. The most recent deposits approach peat in composition,
and the oldest merge into bituminous coal. Lignite contains a larger
percentage of carbon and smaller percentages of hydrogen and oxy-
gen than peat It is often associated with mineral resins or wax-like
hydrocarbons * which may be extracted by means of solvents,

Jet, gagate, azabache and "black amber" are species of lignite.

Cannel coal 10 and bog-head coal and torbanite are in reality a
sub-class of bituminous coal, rich in volatile matter. The former
are supposed to have been derived from spores, spore cases, and
resinous or waxy products of plants (e.g., sapropel). The absence
of woody material gives cannel coal a uniform texture and grain
not present in other coajs, so that it breaks with a conchoidal frac-
ture, and a splinter ignites in contact with a lighted match, burning
like a candle, whence it derives its name.

*The associated resins or waxes, or asphalts, as they are termed by some, have been
described under various names, including: Anthracoxenite, Bombiccite, Branchite, Bu-
tyrellite, Dinite, Dopplerite, Duxite, Dysodile, Euosmite, Fichtelite, Geomyficite, Hartine,
Hartite, Hofmannite, lonite, Koflachite, Leucopetrin, Leucopetrite, Melanchyme, Mellite,
Middletonite, Muckite, Neudorfite, Neft-Gil, Phytocollite, Pianzke, Pyronetin, Refikite,
Retinasphaltum, Retinite, Rochlederite, Schleretinite, Sieburgite, Trinkerite, \Valchowite,
Wheelerite, etc. ; - ,

IV ORIGIN OF NON-ASPHALTIC PYROBITUMENS 97

Bituminous coal falls between lignite and anthracite coal. It is
often a matter of difficulty to determine where the lignites stop and
the bituminous coals begin; similarly, the line of demarcation be-
tween bituminous and anthracite coals is not very distinct. Bitu-
minous coals contain a larger percentage of carbon and smaller
percentages of hydrogen and oxygen than lignite. The name "bi-
tuminous coal" is derived from the fact that this coal apparently
softens and undergoes fusion at a temperature somewhat below that
of actual combustion. The term, however, is a misnomer. The
softening which takes place marks the point at which destructive
distillation commences, accompanied by the formation of gaseous
hydrocarbons. "Bitumen" does not actually exist in bituminous
coal. That portion which dissolves in solvents (e.g., xylol, phenol,
tetralin, etc.) has been termed "bituminic substance," since it re-
sembles bitumens. The insoluble portion has been termed the "lig-
nitic residue," since it resembles lignite. Bituminous coals contain
a substantial portion of volatile matter, which causes them to burn
more rapidly than anthracite, and with a larger amount of flame.
The so-called "coking coal" is a class of bituminous coal, used in
the manufacture of coke. The relationship between bitumens and
coal has also been traced by the similarity of the substances sepa-
rated by the selective action of certain solvents, in their deportment
under heat, vacuum distillation, behavior towards chemical agents,
etc. 11

Anthracite coal represents the final stage in the transformation
of vegetable matter into a non-crystalline form. It contains definite
proportions of hydrogen and oxygen. Certain forms of anthracite
approach graphite in their composition. Graphite on the other hand
is a crystallized mineral composed entirely of carbon, and which is
supposed to represent the final stage in the metamorphosis of coal.
The mode of occurrence and microscopic structure of graphite de-
posits corresponds closely with those of coal, giving rise to the belief
that both were derived from a common source.

CHAPTER V

ANNUAL PRODUCTION OF BITUMINOUS SUBSTANCES
AND THEIR MANUFACTURED PRODUCTS

PRODUCTION OF ASPHALTS, ASPHALTITES AND ASPHALTIC

PYROBITUMENS

World Production. Deposits of natural asphalts have been dis-
covered in all parts of the world. Table VIII, compiled from data
furnished by the Department of Interior of the U. S. Geological
Survey, shows the total production of all forms of native asphalts
(including pure and rock asphalts), asphaltites and asphaltic pyro-
bitumens, from 1906 to 1931 inclusive, as far as reliable statistics
are available. 1

In 1931, the United States produced the largest quantity of
native asphalts, having assumed the lead since 1920. Italy ranks
second, followed by Trinidad, Germany, France and Venezuela, in
the sequence stated.

Production in the United States. Table IX gives the total
production by states in the United States of natural asphalts, as-
phaltites and asphaltic pyrobitumens for the years 1911 to 1935
inclusive, and Table X gives the production by varieties of natural
asphalts, asphaltites, asphaltic pyrobitumens and petroleum asphalts
from 1900 to 1935 inclusive.

No appreciable tonnage of asphalt was produced in the United
States until 1883, when about 35,000 tons was imported mainly from
Trinidad, which found its way into pavements. Prior to this, rela-
tively small quantities of Trinidad was used, whereas European
rock asphalts were imported for this purpose. In 1892 Trinidad
asphalt had displaced most of the European products, and in that
same year Bermudez asphalt made its appearance and gradually
increased until 1919, when its tonnage approximated that of Trini-
dad asphalt.

V PRODUCTION OF PETROLEUM ASPHALTS 99

The petroleum first known in the United States was derived
from the Pennsylvania, Ohio and Indiana fields. This was of the
paraffin type, and when distilled it left a viscous residue, more or
less asphaltic in character, which was used principally to flux the
harder native asphalts. This flux could not be distilled to a solid
without decomposition and the formation of coke. In 1894 Byerley
was granted a patent for converting these fluxes into semi-solid resi-
dues by blowing air through them at high temperatures, thus per-
mitting them to be used without admixture for most purposes,
although they never met with much favor in the paving industry.
Upon the discovery of petroleum in California it was possible to
obtain semi-solid to solid residual asphalts, closely resembling the
native asphalts, and suitable for use in the construction of pave-
ments. In 1902, petroleum asphalts found their way on the market
in appreciable quantities, about 20,000 tons having been produced
in that year. By 1911, the tonnage of domestic petroleum asphalts
exceeded the importations of Trinidad and Bermudez asphalts com-
bined, and from that time on the production of petroleum asphalts
rapidly increased. In 1913 large quantities of Mexican petroleum
asphalt found their way into the United States and rapidly increased
until in 1918 it exceeded the domestic production. Since 1922,
asphalt produced from Venezuela petroleum has been produced in
rapidly increasing quantities, followed in 1925 by asphalt derived
from Colombian petroleum.

At the present time petroleum asphalt far outranks other as-
phalts in importance. In 1935 the total tonnage of petroleum
asphalt was almost ten times that of native asphalts and related
substances. Of the total production, approximately 60 per cent
was reported as having been derived from domestic crude petro-
leum, and 40 per cent from foreign crudes, including Venezuelan,
Mexican and Colombian petroleum.

Table XI shows the production of petroleum asphalts by va-
rieties in the United States in 1935, divided into two classes solid
and semi-solid products of less than 200 penetration and semi-solid
and liquid products of more than 200 penetration. The major por-
tion of the latter class is known by the general term "flux," which
as the name implies, is used mainly as a blending material for the
harder grades and also for blowing purposes.

100

ANNUAL PRODUCTION OF BITUMINOUS SUBSTANCES

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^ "t 10

s I

in R

O "

>s ^ K

00* CO VO cf to tC 00*

M M OO ON co

N co VO co N

p, : o, o\ ^

CO * tO M H

*voo
*WfO
I VO ON

tC V

<N 00 VO <N CO H Tt <N

> VO VO to^><s too t^to;

? M" 4 vp" co O" co

% io N

OO" to O
ON 00

J I 41 I

102

ANNUAL PRODUCTION OF BITUMINOUS SUBSTANCES

<
!f

3 I

H B

oo"SS>

I M NO Bf tO

h ts.OO M t M

!. ?

< W M M

10 to o r 10 t l

Q *4r

Ox M

M ro M O t
fOOSOtN.?

3^^
o to

*? *? 9. *! *! ^ 9. 1
oo""o*toM'M K ^ oTcS

M ^ O NO ON ^* ON O

T tooo* O
to c to *

M w ?o ^* to\O t-00 ONO^

MMMKMMMMMMC4

St toNO t> oo i
$
O\ ON ON ON ON (

M M M M M M

H W O "<* W>

N O^ O^ ON ON ON

M M M MM

.1'

||f a

1? s- I
]]]

iUg
Ofcfc E

T ed" J

111*3!

S'? X R ^"S;

g'SfglS'
if fill

131121

SSSSSS

I I

*S >

|2 .1

"tall^l

a s si o-j

all?!

fl tn&

3 S3SS

PRODUCTION IN THE UNITED STATES

103

TABLE X

PRODUCTION BY VARIETIES IN THE UNITED STATES OF NATURAL ASPHALTS, ASPHALTITES,
ASPHALTIC PYROBITUMENS AND PETROLEUM ASPHALT (1900-1935)

(In Short Tons of 2000 Ib.)

Year

Natural
Asphalts

Asphaltites

Asphaltic
Pyro-
bitumens

Total
Natural
Asphalts,
Asphalt-
ites and
Asphaltic
Pyro-
bitumens

Petroleum Asphalts

Gilsonite

Grahamite

Wurtzilite

From
Domestic
Petro-
leum

From
Foreign
Petroleum

Total Do-
mestic and
Foreign

1900
1901
1902
1903
1904
1905
1906
1907
1908
1909

54,389
63,134
84,632
55,o68
64,167
62,898
73,o62
85,913
78,565
99,o6i

20,826
46,187
44,405
52,369
64,997
137,948
119,817

J 29,594

20,826
46,187
44,405
52,369
64,997
137,948
119,817

129,594

59,639
49,982
58,163
64,240
57,296
66,278

2,978
10,916

12,447
20,285

18,533
28,669

1,000
1,500

I)9 H

966
2,286
3,894

550
500
500
422
450

220

1910
1911
1912

1913
1914
1915
1916
1917
1918
1919

70,061
51,228
55,236
57,549
51,071
44,329
63,172

4i,9i9
25,346
53,589

25,432(*)
30,236
31,478
28,000(0)
1 8,548(0)
19,909(0)
24,5H(*)
33,549(*)
30,848
29,192(0)

4,000 (a)
5,000
7,700 (a)
6,500 (a)
9,669
10,863

8,431
4,618

3,803 W

5,ooo (a)

400 (a)
610
750 (a)
700(0)
600 (0)
650 (0)
2,360 (0)
1,51 8 (ac)

37 W

5oo (0)

98,893
87,074
95,166
92,604
79,888
75,751
98,477
81,604
60,034
88,281

161,187

277,192

354,344
436,586
360,683
664,503
688,334
701,809
604,723
614,692

161,187
277,192
354,344
551,023
674,470
1,052,821
1,260,721
1,347,422
1,202,420
1,289,568

i M,437
313,787
388,318

572,387
645,613
597,697
674,876

1920
1921
1922
1923
1924
1925
1926
1927
1928
1929

132,353
284,037
298,047
365,601

525,831
545,o6o
672,750
796,100
760,497
748,550

56,204
10,066
29,693
34,425
35,907
39,520
42,190
42,580
47,023
54,987

9,940 (b)
2,004
41

198,497
296,412
327,792
400,236
562,367
584,850
715,180
839,040
807,860
804,027

700,496
624,220
805,145
995,654
,158,456
,206,700
,245,160
,525,420
,930,536
2,332,973

1,045,779
908,093
1,242,163
1,378,722
1,920,915
1,971,670
2,213,310
2,426,030
2,298,848
2,355,498

1,746,275

1,532,313
2,047,308
2,374,376
3,079,371
3,178,370
3,458,470
3,951,450
4,229,384
4,688,471

305
II
210 (e)

569 w

270
240

360 Or)

340 tt)
490 (l)

1930

1931
1932

1933
1934
1935

664,871
470,491

3H,039
285,070

410,453
3H,i09

37,684
32,763
25,955
28,029

30,355
33,227

222

129

2 I
36

702,777

503,383
340,019

313,135
440,808

347,336

1,403,552

1,274,744

i," 5,547
1,237,386
1,444,846
1,801,778

1,824,089
1,700,946
1,359,372
1,218,665
1,395,650
1,485,225

3,227,641

2,975,690
2,47^,919
2,456,051
2,840,496
3,287,003

(a) Estimated.

(b) Including wurtzilite.

(/) Including 300 tons ozokerite,
(f ) Including 80 tons ozokerite.
(k) Including 150 tons ozokerite,
(i ) Including 290 tons ozokerite.

104

ANNUAL PRODUCTION OF BITUMINOUS SUBSTANCES

TABLE XI

ASPHALT AND ASPHALTIC MATERIAL (EXCLUSIVE OF ROAD OIL) SOLD AT PETROLEUM
REFINERIES IN THE UNITED STATES, IN 1935, BY VARIETIES

[Value f. o. b. refinery]

From Domestic
Petroleum

From Foreign
Petroleum

Total

Short
Tons

Value

Short
Tons

Value

Short
Tons

Value

Solid and semisolid products of less
than 200 penetration: *
Asphalt for:
Paving

4i9,77i
303,234
83,294
3,i87
37,674
192

6,212
6,856

47,749

13,994,713
3,170,647
917,623
40,663
416,870
1,718
"3,3"
75,9H
500,746

457,695
328,138
65,821
",944
3,271
2,310
1,728
7,814
56,836

$4,805,877
3,585,501
703,7"
136,081
39,305
25,393
16,963
85,016
639,325

877,466
631,372
i49,"5
15,131
40,945
2,502
7,940
14,670
104,585

$8,800,590
6,756,148
1,621,334
176,744
456,175
27,111
130,274
160,930
1,140,071

Roofing

Waterproofing

Blending with rubber

Briquetting

Mastic and mastic cake

Pipe coatings

Molding compounds

Miscellaneous uses

Total

908,169

67,393
225.I9S
3,736

$9,232,205

935,557

45,673
54,649
24,074
32
329,899
17,449
8,528
17,624

$10,037,172

1,843,726

$19,269,377

Semisolid and liquid products of
more than 200 penetration: *
Flux for
Paving \

$581,032
1,540,995
58,480

$432,539
616,485
299,767
320
3,481,445
119,861

83,321
142,605

113,066
279,844
27,810
32
707,953
39,861
20,744
109,566

$1,013,57!
2,157,480
358,247
320
7,409,279
359,650
245,941
540,813

Roofing

Waterproofing

Mastic

Cut-back asphalts

378,054
22,412
12,216
9i,942

3,927,834
239,789
162,620
398,208

Emulsified asphalts and fluxes

Paints, enamels, japans, and lacquers
Other liquid products

Total

800,948

$6,908,958

497,928

$5,176,343

1,298,876

$12,085,301

Grand total, 1935

i,709,H7
1,353,639

$16,141,163
$13,973,765

1,433,485
1,373,602

$15,213,515
$15,921,674

3,142,60^
2,727,241

$31,354,678
$29,895,439

Total, 1934

* DEFINITIONS

Paving asphalt.*- Refined asphalt and asphaltic cement, fluxed and unfluxed, produced for direct use in the con-
struction of sheet asphalt, asphaltic concrete, asphalt macadam, and asphalt block pavements, and also for use
as joint filler, in brick, block, and monolithic pavements.

Roofing a^>Aofc. Asphalt and asphaltic cement used in saturating, coating, and cementing felt or other fabric
in the manufacture of asphalt shingles.

Waterproofing asfhalt. Asphalt and asphaltic cement used to waterproof and dampproof tunnels, foundations of
buildings, retaining walls, bridges, culverts, etc., and for constructing built-up roofs,

Briquetting asphalt, Asphalt and asphaltic cement used to bind coal dust or coke breeze into briquets.

Mastic and mastic cake. Asphalt and asphaltic cement for laying foot pavements and floors, waterproofing bridges,
lining reservoirs and tanks, capable of being poured and smoothed by hand troweling.

Pipe coatings. Asphalt and asphaltic cement used to protect metal pipes from corrosion.

Molding compounds. -AsphsAte used in the preparation of molded composition, such as battery boxes, electrical
fittings, push buttons, knobs, handles, etc.

Miscellaneous uses. Asphalt and asphaltic cement used as dips, and in the manufacture of acid-resisting com-
pounds, putty, saturated building paper, fiber board and floor coverings, and not included in the preceding
definitions.

F/w*. Liquid asphaltic material used in softening native asphalt or solid petroleum asphalt for paving, roofing,
waterproofing, and other purposes.

Cut-back asphalts. Asphalts softened or liquefied by mixing them with petroleum distillates.

Emulsified asphalt and ftuxes.~- Asphalts and fluxes emulsified with water for cold-patching, road laying, and
other purposes.

Other liquid Products. ^?etTo\e\w asphalt, exclusive of fuel oil used for heating purposes, not included in the pre-
ceding definitions,

PRODUCTION OF ROAD OIL IN THE UNITED STATES

105

ROAD OIL SOLD BY PETROLEUM REFINERIES IN THE UNITED STATES, 1934-35,

BY DISTRICTS

District

934

Barrels

Value

Barrels

Value

938,053

$1,392,665

1,001,845

$1,614,179

88,195

186,298

34,035

64,437

1,984,414

2,390,175

1,957,569

2,439,100

Oklahoma-Kansas-Missouri

942,072

1,071,260

597,450

547,789

Texas:
Gulf coast *

204,888

$274,188

99,969

$153,069

Rest of State

79,969

79,963

22,772

35,775

Total Texas

284,857

$354,iSi

122,741

$188,844

Louisiana- Arkansas :

52,464

$ 9S,o89

68,203

$103,334

157,992

158,104

384,769

357,745

Total Louisiana and Arkansas

210,456

$253,193

452,972

$461,079

1,023,434

$1,431,920

644,485

$1,032,907

California

2,231,272

3,662,336

1,987,835

2,194,621

Grand total

7,702,753

$10,741,998

6,798,932

$8,542,956

106

ANNUAL PRODUCTION OF BITUMINOUS SUBSTANCES

PRODUCTION OF TARS AND PITCHES

Tars Derived from Coal. By far the most important source of
tar produced in the United States is derived from bituminous coal.
The following represents the production in United States gallons : 2

TABLE XII

Gas Works
(Horizontal, Vertical
and Inclined)

Coke Ovens
(All Types)

Water and
Oil Gas

1904

42 million

28 million

9 million

1908

1912

1916

1 80

1918

263

IOI

1919

289

105

1920

361

116

1921

^53

109

1922

328

104

1923

441

1924

422

108

1925

480

1926

529

105

1927

547

1928

632

1929

681

117

1930

602

1931

45i

1932

50 to 40 (est'd)

304

1 10 to 80 (est'd)

1933

363

1934

409

1935

40 (est'd)

468 (est'd)

85 (est'd)

No statistics are available giving the production of the corre-
sponding types of pitch.

Tars and Pitches Derived from Wood. The following figures
have been reported by the U. S. Department of Commerce : 8

Wood Tar
(gallons)

Wood-tar Pitch
(tons)

ion

5, <oo,ooo

iqa<

9,000,000

13,500

TQ27

8,500,000

10,000

IQ2Q

10,500,000

4,500

PRODUCTION OF MANUFACTURED PRODUCTS

107

Other Tars and Pitches. There are no published figures giving
the annual production of other tars and pitches in the United States.
The following estimates have been compiled by the author as a mere
approximation of what he believes to be their present relative
standing.

Tons Annually

Rosin pitch 20,000 to 30,000

Fatty-acid pitch 15,000 to 20,000

Blast-furnace tar and pitch 5,ooo to 10,000

Bone tar and bone-tar pitch 2,000 to 5,000

Shale and lignite tars and pitches 250 to 500

MANUFACTURED PRODUCTS

Bituminous Paving Materials. The total tonnage of all types
of asphalt, including asphalt cements, fluxes, cut-back asphalts, emul-
sified asphalts and liquid residual asphaltic products used for high-
way purposes in the United States have been reported as follows : 4

Year Tons

1925 1,764,700

1926 1,800,180

1927 2,179,100

19^8 2,487,642

'9*9 , 2,655,989

J 930 2,693,552

I9JI 2,901,851

J 932 2,838,344

1933 2,500,110

J 934 2,977,990

1 935 3,225,000

The mileage of improved roads completed and under construc-
tion as of January ist of the current year has been estimated to be
as follows : 5

1935
Miles

1936

Miles

1937

Miles

Sand-clay treated

A O7O

7CO2

c 60

Gravel treated

T-jW"

22 8ol

OVA
0*7 72 C

ji uw j

A 7 IQA

Macadam treated

*-*,yj

11 66d.

* /,/^J
2A 6l C

^J, 1 ^
17 7C6

Low-cost bituminous mixture

) * y j ^'*r
11.I2O

*4, U J3
on 8*72

* hi O v

AC fff

Bituminous macadam

I6.CQ7

jy," /*
16,466

*TJ9JJJ

i6.c<<

Bituminous concrete

IQ.7I7

II C72

ii <8^

* w > / * /

1 *O /*

* *O W >

108

ANNUAL PRODUCTION OF BITUMINOUS SUBSTANCES

Bituminous Roofing Products. Table XIII compiled from sta-
tistics furnished by the Asphalt Shingle and Roofing Institute, New
York City, and the U. S. Department of Commerce, Washington,
D. C, show the sales of asphalt roll-roofings and asphalt shingles
in the United States from 1917 to 1936.

TABLE XIII
SHIPMENTS IN " SALES" SQUARES TOTAL INDUSTRY U. S. A.

Year

Smooth-roll
Roofings

Slate-roll
Roofings

Strip
Shingles

Individual
Shingles

Total
All Types

1917

21,252,000

4,134,000

1,266,600

1,625,000

28,277,000

1918

19,250,000

4,312,000

1,017,000

1,149,000

25,728,000

1919

16,930,000

6,428,000

2,311,600

2,183,000

27,952,600

1926

I7,579,ooo

6,624,000

2,253,900

1,866,000

28,322,000

1921

13,992,000

7,670,000

2,865,230

1,632,000

26,159,230

1922

14,604,000

9,252,000

4,243,630

2,395,ooo

30,494,630

1923

12,558,000

9,847,000

5,602,150

2,492,000

30,499,150

19214.

11,951,450

10,608,100

6,707,950

3,103,000

32,570,506

1925

11,990,709

10,529,521

7,803,202

3,406,975

33,730,4H

1926

13,502,977

11,061,229

8,529,382

3,209,728

36,303,316

1927

14,783,909

10,798,454

9,810,918

2,582,031

37,975,312

1928

16,074,654

9,608,380

9,002,297

1,854,393

36,539,724

1929

17,896,549

9,989,787

9,959,382

2,015,781

39,861,499

1930

I2,359,4H

7,147,670

6,820,775

1,546,238

27,874,097

i93i

10,794,478

5,563,338

4,887,134

i,3i9,752

22,564,702

1932

",996,723

5,493,513

4ii43ii33

1,130,522

22,763,891

1933

13,837,632

5,684,905

4,223,069

991,547

24,737,153

1934

12,837,702

5,489,467

4,422,486

1,255,346

24,005,001

*935

12,485,950

6,426,369

5,350,006

1,787,826

26,050,151

1936

15,251,646

8,005,678

6,851,860

2,118,724

32,227,908

PRODUCTION OF MANUFACTURED PRODUCTS

109

The statistics in Table XIV have been compiled by the U. S.
Department of Commerce, Washington, D. C. : 6

TABLE XIV
PRODUCTS, BY KIND, QUANTITY AND VALUE, 1929, 1931 AND 1935

Kind

1935

1931

1929

Roofing, built-up and roll; asphalt shingles; roof coatings
other than paint, all products

$76,172,740

$58,962,919

$ J 03, 506,090

Roofing

70,589,616

4945335 2

Other products (not normally belonging to the industry) . .
Receipts for contract and custom work

5,517,081
66,043

9,509,567

8,914,512

Roofing, built-up and roll, asphalt shingles, and roof coat-
ings other than paint, made as secondary products in
other industries

3,434,376

6,143,744

Asphalt roll roofing:
Total roofing squares

22,331,481

17 I ?2 I \ 143

Total value

$24,768,468

$20,272,517

$36,109,653

Smooth-surfaced :
Roofing squares

14,373,813

II 659 193

Value

$13,710,544

$11 213,050

Grit-surfaced:
Roofing squares

7,957,668

Value

$11,057,924

<tg' O cg' 467

? ' Z 2

Asphalt shingles:
Total roofing aquares

7,731,034

655852 4

Total value

$26,801,952

$22,566,749

$42,291,343

Strip:
Roofing squares

6,048,383

S2o6 2 ?Q

Value

$21,897,294

$18 328 528

9,692,774

Individual :
Roofing squares

1,682,651

I 352 265

33,707,3 4

Value

$4,904,658

&A 238 221

Saturated felt:
Total tons

298,219

143. CT2

3, 5

Total value

$8,042,840

$6,025,401

2O5j5 2 5
$9,803,629

Asphalt-saturated felt:
Tons

271,241

IIO 727

Value

$6,237,267

$4 68< 83^

A/- * S

Tar-saturated felt:
Tons

26,978

32 785

f& A(\C\

Value

$1,805,573

$i 339 566

00,499

Waterproofing fabrics, value

$400,417

(a)

v3 7 *

Roof-coatings and cements, total value

NP*frV/v,,<t /

$6,374,359

$4,298,946

$6,311,449

Asphalt roof cement (solid) :
Tons

106,790

16 630

Value

$1,420,651

$333 7 CO

Coal-tar roofing pitch:
Tons

Value

$808,808

I (&)

(a)

Fibrous plastic roof-cement:

31 460 O42

29,488,86l

Value

$1,176,998

$1,347,599

$2 336 III

Fibrous liquid roof-coating:
Gallons . .

4,88l,023

4,979,oi3

4 O4I ^63

Value

$1,928,595

$2,040,783

$2 II 1 ? *!78

Nonfibrous liquid roof-coating:

1,420,622

I O3I 260

Value

$040.217

$1-76.814

$1 OI7 34O

Other roofing materials value

S6.383. 41 7

$2.433 483

$6 168 787

Asphalt brick siding:

m_7O

1 t \

Value

"^
$1,243,539

} (a)

(a)

(a) No data.

110

ANNUAL PRODUCTION OF BITUMINOUS SUBSTANCES

TABLE XIV Continued
PRODUCTS, BY KIND, QUANTITY AND VALUE, 1929, 1931, 1933 AND 1935

Kind

Year

Quantity

Value

1935

Squares
1,171,095

$5,234,727

J933
1931
1929

J 93S

408,256
565,997
894,164
890,854

1,826,279
3,266,054
5,277,308

C67.QII

Asphalt roll roofing (c)

1935

22,331,481

24,768,468

Asphalt shingles (d)

1933
I93i
1929

1935

12,333,342
17,525,143
28,437,076

7,731,034

12,763,519
20,272,517
36,109,653

26,801,952

Asphalt and tar saturated felt (d)

1933
i93i
1929

1935

4,008,811

6 >558,524
11,676,636
Tons (2000 Ibs.)
298,219

11,994,618

22,566,749
42,291,343

$8,042,840

Clay roofing tile (e)

1933
i93i
1929

1935

75,623
143,5"

205,525
Squares
253,951

2,778,308

6,025,401
9,803,629

1,145,434

Concrete roofing tile (f)

1933
i93i
1929

1935

103,257
285,253

370,771
Tons (2000 Ibs.)
(g)

810,647

3,125,175
3,943,847

(g)

Steel sheets, corrugated and crimped (h):
Galvanized

1933
i93i
1929

IO^S

11,971
31,860
137,052
Tons (2240 Ibs.)

e8. S74.

338,809
862,197
2,869,092

27 611 766

Not galvanized

1933
1931
1929
1935

243,542
262,307
306,423
6,506

15,922,000
18,381,000
26,363,000

ex.2 O8l

Wood shingles (*)

1933
1931
1929

TQ7 e

2,338
3,O26
5,285

Thousands
3^26 ^18

140,000
175,000
380,000

10 ^^8 ^60

Asphalt roof-cement (solid) (c)

1933
1931
1929

IQ*<

2,929,800
2,713,972
6,110,672
Tons (2000 Ibs.)
106.700

6,958,275
4,993,708
18,026,482

I A2O 6?I

Fibrous plastic roof-cement (c)

1933
1931
1929

1935

io,373
16,630
35,i6i
Pounds

sj 4.60.04.2

255,471

333,750
842,420

1.176.008

Fibrous liquid roof-coating (c)

1933
1931
1929

IO"*{

13,968,939
29,488,861

52,753,395

Gallons
A 881 02 *

**/w,yyo
661,044

1,347,599

2,336,111

i 028 <co<

Nonfibrous liquid roof-coating (c)

1933
I93i
1929

1935

3,003,734
4,979,oi3
4,941,563

3,424,671

1,011,323
2,040,783
2,115*578

O4.O.2I7

1933
1931
1929

799,844
1,420,622
1,931,269

183,729
576,814
1,017,340

(a) Made in the Asbestos Products industry, (b) No figures available for earlier years, (c) Made principally
in the Roofing Materials industry, (d) Made in the Roofing Materials industry, (c) Made in the Clay Products
industry, (f) Made in the Concrete Products industry, (g) Not yet available. (A) Made principally in the
Steel Works and Rolling Mills industry, (h) Made in the Lumber and Timber Products industry.

PRODUCTION OF MANUFACTURED PRODUCTS

111

Asphalted Felt-base Floor Coverings. The data in Table XV
have been compiled by the U. S. Department of Commerce, Wash-
ington, D. C. : 7

TABLE XV

ASPHALTED FELT-BASE FLOOR COVERING PRODUCTS, BY KIND, QUANTITY AND VALUE

1935

1931

I 9 2 9

Total square yards

128,041,256

87,575,642

117 060 72 C

Total value

t3 I >*S9>943

$21,628,899

$36,943,057

Piece goods:
Total square yards

66,610,504

48,401,10

57.O26 l6o

Total value

$ 1 4,46 1, 266

$11,341,150

$I4,68O,OI7

12/4 an d wider:
Total square yards

2O.7O4.420

5.2IO.5QO

6 060 cci

Total value

$4,412,620

$1,227,276

u >y v - n -'o$j
$2,032,865

Made on less than .050-! nch-gauge felt:
Square yards

1 2. 11O.OO 5

2.444.084

2 1 60 III

Value

$2,448,780

$5O2.Q1O

^,iuy,i 1 1
$ Coo 821

Made on .O5o-inch-gauge felt or thicker:
Square yards.'

8,374,424

2,76C,6o6

f jvy^ojii.
4.7QI.442

Value

$I.Q6l.8lI

$724.146

$1 C21 OA.A.

8/4:
Total square yards

4.1.766.061

l8,886,OQ6

' A >J < *J> W T^

44 4OO 278

Total value

19,53!, 5^4

$9,110,304

$11,621,078

Made on less than .050-1 nch-gauge felt:
Square yards

24,644,42 5

22,824,070

2 1.8OO.2O1

Value

$5,124,065

$4.<84.784

$C~d.7O 6l2

Made on .O5o-i nch-gauge felt or thicker:
Square yards

10,121,618

l6,o6l,II7

fjrr/^yJjA
2O COO 08 C

Value

$4.4O7.45Q

$4,525,520

' t '^'9jy^ J )y Q j
$6 I CO*AA6

Narrower than 8/4:
Total square yards

2,l6o,IO2

4.1O4.47I

f>V/,l^W^J.^.V

C 66 C C2O

Total value

$517,122

$1,003,570

$1,026,074

Made on less than .O5o-inch-gauge felt:
Square yards

1,224,071

1,658,007

C.4Q4 6 CO

Value

$285.804

$807 1 06

$06 c 87^1

Made on .050-! nch-gauge felt or thicker:
Square yards

Ol6 O2Q

645 474

ry u j>/4
I7O 87O

Value

$231,228

4 1 06 464

1 /U,O /U

26o 2OO

Rugs:
Total square yards

6l,4l2,662

10. 1 74 48C

J>UV)4VAJ

60 QAl l6c

Total value

$16,798,677

$10,287,749

uw >y4J,J u J
$22,263,040

Made on less than .050-1 nch-gauge felt:
Square yards

11 741.412

2 C.148 .060

27 2QO.1O1

Value

28.142.774

$5,76o,542

^/j^^y >o w j
$7.758,888

Made on .050-1 nch-gauge felt or thicker:
Square yards .

27.671 .2 CO

11.826,425

11.644.062

Value

$8,455,QO1

$4.527.207

$14,504.152

PART II

SEMI-SOLID AND SOLID BITUMENS AND
PYROBITUMENS

CHAPTER VI
METHODS OF MINING, TRANSPORTING AND REFINING

MINING METHODS

Three general methods are followed in mining semi-solid and
solid bituminous substances, depending upon the nature of the
deposit.

Open-cut Quarrying. Deposits at or near the surface are mined
by simple quarrying methods. If exposed on hillsides, the rock
asphalt is blasted loose and loaded on railroad cars by means of
steam shovels or buckets running on a cable way. Deposits located
beneath flat terrain are mined by open cuts, after first removing the
overburden, as illustrated in Figs. 46 and 49. The asphalt may be
hauled from the cut by means of buckets suspended from an over-
head cable way, or by dump-cars pulled up inclined tracks on cables.

Tunnelling. Veins situated a distance beneath the surface are
mined by tunnelling methods, which also adapt themselves to
handling veins filling hillside faults or fissures. Typical tunnelling
methods are illustrated in Figs. 64 and 69. Horizontal veins may
be handled by pit-and-stall methods if the overlying stratum is solid
enough to resist caving in, otherwise the roof and possibly also the
sides of the tunnel must be timbered, which of course adds to the
cost of mining, Asphaltites are generally mined in this manner.

Special Methods. Asphalts deposits occurring in the form of
so-called lakes, as for example at Trinidad and Bermudez, are mined
by comparatively crude methods, involving the use of the pick and

shovel, as illustrated in Figs. 43 and 59. The asphalt is dumped

112

METHODS OF SHIPMENT AND TRANSPORTATION

by hand in small cars on a movable track, whence it is transported
to the main railroad line or to steamers, if near the seacoast.

METHODS OF SHIPMENT AND TRANSPORTATION

Hard rock asphalts and asphaltites are shipped in fragments,
either in bulk the same as coal, or if the material is of sufficient
intrinsic value to warrant the expense, it may be shipped in sacks
weighing 150 to 200 Ib. each. Where intended for constructing
asphalt mastic pavements or floors, the rock asphalt is cast in the

Courtesy Atlantic Refining Co.
FIG. 35. Tank-cars Used for Transporting Asphalt.

form of flat cakes weighing between 50 and 75 Ib. for the con-
venience of handling.

If the asphalt is comparatively free from mineral matter, and
this applies also to petroleum asphalt, it may be shipped in six
types of containers, as follows: 1

(i) In tank cars having capacities of 6500, 8000 and 10,000
gal. as illustrated in Fig. 35. These are provided with steam coils
for remelting the asphalt upon arrival at destination, and are prefer-
ably insulated, so that they may be transported in a melted state
with the minimum loss of heat.

114 METHODS OF MINING, TRANSPORTING AND REFINING VI

(2) Tank trucks equipped with heating flues in which a fire is
maintained by an oil burner during transit. These are generally
used for transporting asphalts for road and paving purposes.

(3) Light metal drums with a metal top having a 6-in. hole in
the center for convenience in filling. These usually weigh 475 to
525 lb., holding 50 to 55 gal.

(4) Wooden barrels of about the same capacity as stated in
(3). These are generally used for transporting liquid to semi-
liquid materials, and are filled at the lowest temperature to prevent
excessive contraction taking place upon cooling.

(5) Fiber barrels and other containers, 2 which should be filled
at temperatures lower than 300 F. It is recommended that these
be lined with clay to prevent adhesion of the asphalt 3 and thus
facilitate stripping off the container when used. Other products
recommended for this purpose include alkaline sludge obtained as
a by-product in refining petroleum products, 4 glycerol foots, 5 an
aqueous solution of oxalic acid or sodium-hydrogen phosphate con-
taining glycerol, 6 etc,

(6) Molds for the shipment of high melting-point asphalts,
which may be of the same form as barrels. These are filled in the
same manner as drums, and when the asphalt has cooled, they are
opened up and the block removed and shipped as such. 7 The
cakes may also be coated with a high fusing-point asphalt or as-
phaltite (e.g., gilsonite). 8 This method eliminates the payment of
freight on the container, but only adapts itself to materials which
are sufficiently rigid and tough to withstand shipment.

METHODS OF REFINING

Dehydration. Most native asphalts contain more or less mois-
ture, which may be present either accidentally as hydroscopic
moisture, or in the form of an emulsion. Trinidad asphalt is an
'example of the latter, in which about 29 per cent of water is emul-
sified with the asphalt and clay.

Before the asphalt can be used commercially, this water or
moisture must be removed. The process by which this is accom-
plished is known as "dehydration." The expulsion of water is
brought about by heating the asphalt in a suitable open container
constructed of iron or steel, which is built in two types, viz. :

(1) Semi-cylindrical.

(2) Rectangular.

METHODS OF REFINING

115

In either case the top is left open so that the water may be
expelled readily. In modern plants, the heating tanks are built to
contain between 10 and 30 tons of the crude asphalt.

The heating is effected by various means:

( i ) By direct fire heat, in the form of a combustion chamber
underneath the tank, enclosed in fire bricks. Three kinds of fuel are
used for this purpose, depending upon which is most readily ob-
tained in the locality where the asphalt is to be refined; namely,
coal or coke, oil, or gas. Coal is burnt on a grate ; oil is usually

FIG. 36. Showing Arrangement of Refining Stills for Natural Asphalt.

sprayed into the combustion chamber by compressed air or steam ;
and natural or producer gas is introduced through a suitable type
of burner. 9 In any case, the best practice consists in protecting
the bottom of the melting-tank by a fire-brick arch work, so that
the hot gases are compelled to circulate back and forth. 10 This
subjects the bottom of the tank to a more uniform temperature, and
tends to prolong its life. At the same time, it economizes fuel by
more thoroughly extracting the heat from the hat gases, due to the
increased area of contact with the bottom of the tank. Some recom-
mend the use of a perforated brick arch to distribute the hot gases
uniformly and prevent the bottom of the tank from being^ over-
heated locally. Fire melting-tanks are usually semi-cylindrical in
form, although sometimes they may be rectangular at the top, with
a semi-cylindrical bottom.

116 METHODS OF MINING, TRANSPORTING AND REFINING VI

(2) By means of steam. In this case the heating is effected by
coils of steam pipes contained in the tank. One and one-quarter to
i^-in. pipes are generally used for this purpose. According to the
best practice, these are bent in coils composed of a continuous
length of pipe without unions or joints, as illustrated in Fig. 36. X1
Another method consists in using cast-iron headers with straight
lengths of 1^4 or i ^-in. pipes fastened in between. Steam is used
at pressures between 125 and 150 Ib. This will raise the tempera-
ture of the asphalt to 300 or 400 F. Steam has the advantage
over fire heat in not coking the asphalt, which would tend to insu-
late the bottom, induce local overheating, and burn out the tank in
a comparatively short time.

Courtesy of Parks Cramer Co.
p IG . 37 . Hot Oil Circulation Method for Heating Asphalts.

(3) Electrical Immersion Heaters. 12 Electric heating units
contained in a series of ic-in. pipes (closed at both ends) are placed
at the bottom of the tank. Each unit has a capacity of 54 k.W.
and serves to heat the air in the pipe, which in turn imparts its
heat to the surrounding asphalt. This same device has been uti-
lized for saturating roofing felt, in which case the asphalt is main-
tained at 440 F. while the felt is being treated at the rate of I ton
per hour, which corresponds to a heat consumption of about 10,000
B.t.u. per hour per ton of asphalt.

(4) By contact with molten metals or alloys. Another pro-
cedure consists in promoting the rapid heating of the asphalt by a
bath of molten lead, tin, zinc, or various alloys of low fusing-
point. 18

VI METHODS OF REFINING 117

(5 ) By hot oil circulation. This is accomplished by circulating
heated mineral oil of a high flash-point through a closed system of
pipes, including a heating coil in the asphalt melting tank and a
second coil located in a furnace situated a short distance away from
the tank. The second coil is heated by means of an oil or gas
burner, which by means of a thermostatic control serves to heat the
oil to a predetermined temperature, usually at 550 to 600 F. Fig.
37 illustrates the oil heater and circulating pump. 14

(6) By means of diphenyl vapor. Dbhenyl is a white solid,
melting at 156.6 F. and boiling at 491.5 F. under a pressure of I
atmosphere. At 491.5 F. it has a pressure of 14.7 Ib. absolute
and at 600 F. it has a pressure of only 47 Ib. In view of these
properties, its use has been promoted for heating asphalts, etc. 15 A
mixture of diphenyl and diphenyl oxide has also been proposed, 16
likewise naphthalene.

(7) By circulating the asphalt itself. 17 This is a modification of
the preceding method, in which the mineral oil is replaced by the
asphalt which is to be heated. In this case the heating coil in the
asphalt melting tank is omitted, and the asphalt is pumped directly
from the bottom of the tank through a heating coil in the outside
furnace, and then back again into the melting tank. The heating
coil is brought to the proper temperature (which may be controlled
thermostatically) by oil or gas combustion. This procedure^ is
simple and efficient, but adapts itself only to asphalts having a high
flash-point and which are substantially free from mineral matter or
other ingredients which will settle in the coils and induce carboniza-
tion. The asphalt must also be free from water and capable of
being heated rapidly without frothing.

The time of heating can be reduced materially by agitating the
asphalt mechanically, since the transfer of heat through a mass of
asphalt is very slow. The agitation may be Accomplished:

(a) By jets of dry steam which should be introduced after the
temperature of the asphalt becomes sufficiently high to prevent con-
densation, and thus avoid excessive foaming. 18

(b) By jets of air.

During the process of dehydration, the mass is apt to froth when
the temperature is raised beyond the boiling-point of water. For
this reason, it is well to build the tanks large enough to accommo-
date the foam without danger of overflowing. Shallow tanks are
preferable to deep tanks.

118 METHODS OF MINING, TRANSPORTING AND REFINING VI

Certain types of asphalt are most difficult to dehydrate, as they
foam very badly. Numerous devices have been used to keep down
the foam, the simplest and most successful consisting in directing a
current of hot air against the surface of the asphalt while it is being
melted.

The use of steam accelerates the evaporation of the more vola-
tile constituents in the asphalt, and is therefore apt to cause a
greater shrinkage during the dehydration than when air or mechani-
cal mixing is used. 19 On the other hand, air is apt to "oxidize" the
asphalt and increase its fusing-point, especially if its use is con-
tinued for long periods of time.

Sometimes the asphalt is subjected to a process of partial distilla-
tion in a closed retort to remove the volatile constituents and raise
its fusing-point, which, 'however, is stopped before the formation of
carbonaceous matter. 20 A modification consists in adding a propor-
tion of vegetable oil during the refining process for the purpose of
absorbing the sulfur derivatives loosely combined with the asphalt; 21

Any impurities such as vegetable matter, chips of wood, etc.,
which rise to the surface when the asphalt is melted should be
skimmed off. When the asphalt is thoroughly melted and the foam-
ing ceases, the dehydration is complete. It is usually unnecessary to
raise the temperature of the asphalt higher than 350 F. The de-
hydrated asphalt may be discharged :

1 i ) By a valve at the bottom of the tank, permitting the asphalt
to flow out by gravity.

(2) By a rotary pump which may either be steam-jacketed 22
or surrounded by a steam coil in close contact with the pump, the
entire installation being well insulated. The rotary pump is usually
installed above the level of the asphalt, and the intake pipe extended
almost to the bottom of the heating-tank.

(3) By means of a pneumatic lift installed below the bottom of
the tank. The asphalt is allowed to flow by gravity into the pneu-
matic lift, which, by a suitable mechanism, automatically shuts off
the flow when it is filled, and then admits compressed air, forcing
the asphalt upward through the discharge pipe. The pneumatic lift
may either be steam-jacketed or heated with a steam coil as de-
scribed.

(4) By means of an Archimede's screw, which serves to extrude
asphalt compositions in the plastic state. 23

METHODS OF REFINING

119

A device for discharging the melted asphalt into light metal
drums, in which nine are filled simultaneously, is illustrated in
Fig. 38.

Asphalt may be pumped through pipe lines for distances of 500
feet or more. To effect this it must be maintained in a melted
state. This is accomplished by running a steam pipe of small

Courtesy Atlantic Refining Co.
FIG. 38. Discharging Melted Asphalt into Drums.

diameter inside the pipe carrying the asphalt. 24 The outer pipe

should be well insulated.

Hard asphalts are first pulverized and then dried in air. 25
Distillation. Attempts have also been made to utilize rock

asphalts associated with a small percentage of bituminous matter,

and which cannot be utilized for other purposes, by subjecting them

120 METHODS OF MINING, TRANSPORTING AND REFINING VI

to a process of destructive distillation 26 and recovering the volatile
products, including the lubricating oil fraction, 27 which correspond
closely with those obtained upon distilling pyrobituminous shales.

FIG. 39. Jaw Crusher.

However, the low market price of petroleum has been an obstacle
to the success of such operations.

Rock asphalts may be distilled to harden same for use in paving

FIG. 40. Toothed-Roller Crusher.

impositions. 28 If coarse or undesirable mineral aggregate is pres-
mt, it may be screened to the desired mesh while in a melted state,
ind electrically heated screens have been proposed for this purpose.

METHODS OF REFINING

121

Comminution. Natural rock asphalts and asphaltites may be
comminuted 30 in three different types of apparatus, including jaw-
crushers illustrated in Fig. 39, toothed rollers as illustrated in Fig.

FIG. 4IA. Disintegrator (Showing Wheels Separated).

40, and a disintegrator as illustrated in Figs. 41 (A) (showing the
machine taken apart) and 41(6) (showing the machine assembled).
After being crushed and ground, the product is screened to the re-

FiG. 4iB. Disintegrator (Showing Machine Assembled).

quired mesh, and finally heated in a revolving, fire-heated cylinder to
expel the associated moisture, usually at a temperature of 260 to
300 F. The asphalt content of the comminuted material can be

122 METHODS OF MINING, TRANSPORTING AND REFINING VI

adjusted by grinding together rock taken from the rich veins with
material mined from the poorer strata. When used for paving
purposes, the product is usually transported directly to the job
while it is still hot. 31

Sedimentation. This process is used to separate the water where
it is present in substantial quantities, as well as any coarse particles
or lumps of mineral matter. It can only be used successfully with
asphalts or other forms of bitumen melting below the boiling-point
of water (212 F.), and not carrying the water in an emulsified
state. The asphalt is maintained at a temperature not exceeding
200 F. by any of the devices described under "Dehydration," and
allowed to undergo a process of sedimentation, whereby the en-
trained water and coarse mineral matter settle to the bottom, leav-
ing the purified asphalt on top. The latter is then carefully drawn
off. 32 Steam heating is most satisfactory for this purpose.

In some cases only a portion of the water separates by sedimen-
tation, whereupon the process is supplemented by one of dehydra-
tion. The sedimentation will remove most of the water and has
the advantage of materially shortening the dehydration process.
A combination of the two processes will thus prove more effective
than the use of either one alone.

Since water usually has a higher specific gravity than melted
asphalt, it tends to settle to the bottom of the vessel containing it.
This invariably proves to be the case with the softer forms of na-
tive asphalt.

Extraction. Two media have been used for this purpose, namely
water and volatile solvents. As the methods are entirely different,
they will be considered separately.

Extraction by Means of Water. This method has been used
with more or less success for extracting asphalt from asphaltic sands,
sandstone and limestone. It is based on the principle that water
has a higher specific gravity than the melted asphalt, and a lower
gravity than the accompanying mineral matter, so that when boiled
together, the melted asphalt will rise to the surface and the mineral
constituents settle to the bottom. 33 Calcium chloride, 84 sodium car-
bonate 85 and salt ae have been proposed to be added to the water
to increase its gravity and thereby effect a more thorough separa-

VI METHODS OF REFINING 123

tion of the asphalt. Rock asphalts after weathering yield more
difficultly to the water-separation process. 87

To yield successfully to this method, the rock asphalt must pos-
sess the following characteristics:

1 i ) The asphalt present in the rock should have a fusing-point
of not exceeding 90 F. (Test 150.)

(2) The particles of mineral matter should be unconsolidated.

3 C rr\t f f t ., 1 111 _ 1 ._ ,_

(3) The grains of mineral matter should be fairly coarse to
enable them to settle rapidly.

Experience has shown that when the fusing-point of the asphalt
contained in the rock is higher than 90 F., boiling water will not
effect a thorough separation.

A specimen of asphaltic sand obtained near Woodford, Okla.,
carrying approximately 12 per cent of asphalt and 88 per cent of
sand in the form of loose, rounded grains between 40- and 8o-mesh,
separated fairly completely on boiling with water. The pure asphalt
showed a fusing-point between 65 and 70 F.

Another asphaltic sand obtained near Fort McMurray, in
northern Alberta, carrying approximately 15 per cent of asphalt
and 85 per cent of non-compact sand, between 40- and loo-mesh,
likewise largely separated on boiling with water. The fusing-point
of the pure asphalt was 50 F.

The same was true with an asphaltic sand carrying 1 7 per cent
of asphalt obtained from a deposit 46 miles northwest of Edmon-
ton, and 12 miles north of Onoway. In this case the pure asphalt
fused at 62 F.

A Mexican asphaltic sand carrying 16 per cent of asphalt also
separated completely on boiling with water, the fusing-point of the
pure asphalt being 78 F.

On the other hand, certain asphaltic sands obtained from various
localities of Oklahoma, carrying between 10 and 15 per cent of
asphalt, refused to separate on boiling with water. The fusing-
points of the pure asphalts were found to be 113 F., 118 F., and
127 F., respectively. The particles of the sand were substantially
similar to the preceding, ranging between 40- and loo-mesh.

Plants for the water-extraction of asphalt from rock asphalt
have been in operation in Oklahoma (sand asphalt) ; Texas (as-
phaltic limestone) ; Alberta, Canada (sand asphalt) ; Pechelbronn,

124

METHODS OF MINING, TRANSPORTING AND REFINING

Alsace-Lorraine (asphaltic limestone); Seyssel and Bastennes,
France (asphaltic limestone) ; San Valentino, Italy (asphaltic lime-
stone) ; Tataros, Austria (asphaltic limestone) ; also in Russia
(sand asphalt).

A cross-sectional diagram of an apparatus which gives fairly
successful results is shown in Fig. 42. The separated asphalt must
be treated in accordance with the methods described under the
heading "Dehydration/* to separate the water which is mechanically
carried along with it If the process has been performed properly,
the purified asphalt will not contain more than 5 to 7 per cent of
mineral matter. The water-extraction process also is used for puri-

Perforateef Metal Plat*
TO allow Wafer to dram off
separated Asphalt

iStirring Dev

\ Cham with diodes
\to carry oft separated
asphalt

Pure Asphalt Floats on
Surface o

Vo/res to draw off''
Mtneral Matter ;

Serrf/ngr Chamber for
Mtneral Matter

FIG. 43. Apparatus for Separating Soft Asphalt from Sand by Means of Water.

fying ozokerite and to remove water-soluble constituents (e.g., salt)
from certain native asphalts, and thereby improve their weather-
resisting properties. 38

A flotation process has been proposed, which consists in agitating
the sand asphalt at 60 to 80 C. with a o.i per cent solution of a
froth former, e.g., soda ash, alkaline soap, turkey-red oil, saponin,
glue, etc.; the aqueous solution being then separated by decantation
and the mineral matter removed by lixiviation. 80 The use of ben-
tonite 40 alkali (e.g., NaOH or Na 2 CO 3 ), 41 sodium phosphate, 42 so-
dium silicate, 48 sodium silicate in combination with calcium chloride
or salt, 44 sulfonated mineral oils, 45 etc., have also been suggested
for this purpose.

VI METHODS OF REFINING 125

Extraction or Precipitation with Solvents. Carbon disulfide,
petroleum distillates and benzol have been used for this purpose.
This method has not proven successful commercially, on account of
its expense. Several plants have been constructed in the United
States for extracting asphalts from asphaltic sands and sandstone.
The Alcatraz Asphalt Co. of Alcatraz, Cal. (18961899), erected
an elaborate plant for treating rock carrying 10 to 16 per cent of
asphalt. The venture, however, proved a failure through losses in
solvent (a light distillate of petroleum), which made the cost of
treatment prohibitive. The loss was due in part to unavoidable
evaporation during the extraction process, also ,to the impossibility
of fully recovering the solvent from the extracted residue.

Solvents may be used either to extract solid bituminous sub-
stances (e.g., rock asphalts, sand asphalts, certain pitches, etc.), or
to precipitate components from fluid bituminous substances (e.g.,
petroleum, tars, etc.) or solutions of solid bituminous substances in
various menstra. The following classes of solvents have been pro-
posed for these purposes : 46

(a) Solvents derived from petroleum:

Crude petroleum; 47 liquid ethane, pentane, propane or bu-
tane; 48 light petroleum distillates (e.g., petroleum ether, gasoline,
or petroleum naphtha) ; 49 kerosene; 50 heavy mineral oils; 51 etc.

(b) Solvents derived from coal tar:

Benzol; 52 toluol; 58 xylol (solvent naphtha); 54 heavy oils; 55
naphthalene ; 56 tetrahydronaphthalene ( "tetralin" ) ; 57 nitroben-
zene; 58 benzonitrile ; 59 phenol; 60 phenyl nitrile; 61 aniline; 62 pyri-
dine or quinoline.

Turpentine; 63 methyl or ethyl alcohol; 64 higher alcohols (e.g.,
butyl, isobutyl, propyl, iso-propyl, amyl, fusel oils, benzyl, etc.) ; 65
acetone ; 6e acetone oils ; 67 wood oils ; 68 furfural or methyl furfural
("furfural process"); 69 glacial acetic acid; 70 methyl or ethyl ace-
tate; 71 amyl acetate; crpton aldehyde ("Foster- Wheeler process").

(d) Sulfur derivatives:

Liquid sulfur dioxide ("Edeleanu process"); 72 carbon disul-
fide; 73 sulfo-derivatives of mineral oils and tars. 74

(e) Sundry solvents:

Ethyl ether ; 75 carbon tetrachloride, trichlorethylene, ethyl ene
dichloride, or dichlor-djethyl ether ("chlorex process"); amine
bases (e.g., iso-amyl amine, di-iso-propyl amine, di-iso-butyl amine,
etc.). 76

126 METHODS OF MINING, TRANSPORTING AND REFINING VI

(f) Mixtures of solvents:

Petroleum naphtha with amyl alcohol ; 77 pentane with butane,
or propane with ethane; 7S propane with cresol ("Dusol process") ;
benzol or toluol with alcohols; 79 benzol with acetone; 80 benzol
with liquid sulfur dioxide ( u Edeleanu process"); propane with
liquid sulfur dioxide; 81 ethyl alcohol with ethyl ether; methyl for-
mate with benzol, carbon disulfide or carbon tetrochloride ; 82 phenol
with a polyhydric alcohol ; 83 successively with alcohol, or acetone,
petroleum naphtha, and finally with benzol or toluol. 84

For the production of high-grade lubricating oils from heavy
petroleum fractions, the use of liquid propane as a solvent (or
more accurately, as "antisolvent") has become increasingly popu-
lar. 85 The following constituents present in ordinary lubricating
oil fractions must be eliminated, viz. : paraffin wax to obtain a low
pour-point, asphalt because of its instability and excessive carbon-
forming tendencies, the heavy ends of the lubricating oils because
of their high carbon-forming tendencies, naphthenic compounds of
olefinic or aromatic characteristics because of their low stability and-
low viscosity index, and color bodies to render the lubricating oil
more marketable. Refining with liquid propane makes available as
by-products a whole series of high melting-point waxes, also petro-
latums of extremely high quality, and new types of asphalt of excel-
lent ductility and penetration relations. The same is true to a cer-
tain extent with other light hydrocarbons, including liquid ethane,
which dissolves much less oil than liquid propane and throws asphalt
completely out of solution. A mixture of methane and propane
behaves similarly to ethane. Liquid butane, on the other hand is
too good a solvent to be effective in removing the asphalt. For
the complete removal of wax, asphalt, heavy ends, naphthenic com-
pounds and color bodies, liquid propane is generally more efficient
than any other solvent known at present

Propane gas, by simple compression and liquefaction, may be
converted into a solvent having the unique properties (under proper
conditions of temperature and pressure) of separating each of the
foregoing undesirable constituents. It owes its versatility to the
fact that its properties change rapidly over the particular tempera-
ture range between 44 and +215 F. Over this range, it
possesses the properties of a series of solvents, any one of which
can be obtained by raising or lowering the temperature, or chang-

VI METHODS OF REFINING 127

ing the pressure, or by combining these two operations. Pure
propane boils at 44 F. under i atmosphere pressure, exerts a
pressure of 126 Ib. per sq. in. at 70 F., and has a critical pressure
of 643 Ib. at 212.2 F. Over this range propane changes from a
typical liquid to a fluid possessing substantially the properties of a
gas. Between 70 and 44 F., its main uses are in connection
with dewaxing. At temperatures above 70 F., it finds its use as a
preferential precipitant. Thus, in the range of 100 to 140 F.,
asphalt is only slightly soluble in propane, whereas at these same
temperatures both oil and wax dissolve completely. Between 100
and 212 F. and at the vapor pressure of propane, instead of be-
having as an ordinary liquid and dissolving more of any partially
soluble substances as the temperature is raised, it actually dissolves
less. The heavier and more naphthenic compounds are thrown out
first, but as the properties of propane become increasingly those of
gases, it dissolves less and less oil, until no viscous oil remains in
solution at 212.2 F. the critical temperature of propane. This
property makes it possible to recover by simple decantation a large
proportion of the propane in a substantially pure state, without
the necessity to vaporize it by the usual method.

To utilize these varying properties of propane on a stock con-
taining all the foregoing undesirable constituents, a typical cycle
consists in mixing the oil with 4 to 6 times its volume of liquid
propane at 120 to 150 F., which will throw out of solution prac-
tically all of the asphalt. The latter may be settled out and drawn
off as a liquid because it contains a substantial quantity of dissolved
propane. The remaining solution can then be rapidly chilled by
the simple expedient of lowering the pressure and allowing a small
quantity of the propane to evaporate until a temperature of

20 to 40 F. is attained, whereupon the wax will be

thrown out of solution and may be removed by settling or prefer-
ably by filtration. The propane solution is then brought back to
room temperature, and may either be treated with relatively small
quantities of sulfuric acid to remove the color bodies and naphthenic
constituents, or else be heated without any additions, in stepwise
fashion, to about 200 F. Under these conditions a series of cuts
of varying composition is separated out; the first is composed of
very heavy ends, resinous constituents, and the more heavy naph-

128 METHODS OF MINING, TRANSPORTING AND REFINING VI

thenic constituents of the oil, and each cut becomes lighter and
more paraffinic, until the last material left in solution is a rela-
tively low-boiling, highly paraffinic, light-colored oil.

The term u propane de-asphalting" is usually applied to those
cases where the heavy product is a mixture containing black, pitchy
material. This operation may include removal of only a small
amount (approximately 3.5 per cent) of high melting-point asphalt
from a Mid-continental crude, to a much larger percentage from a
California crude. In the latter case, the separated asphalt had a
specific gravity at 60 F. of 1.031, a penetration at 77 F. of 35,
a fusing-point (R. and B. method) of 118 F., and over 99.6 per
cent soluble in CS 2 , CC1 4 and 86 petroleum naphtha, respectively.

Attempts have also been made, but without success, to utilize
the solvent extraction method to recover the bituminous constitu-
ents and felt respectively from the waste material produced in the
manufacture of asphalt roofings and shingles. 86 On the other hand,
it has given satisfactory results in recovering montan wax from
lignite at Thuringia, Saxony, and from pyropissite at Weissenfels,
near Halle, Germany. Benzol is generally used for this purpose,
although in certain cases petroleum distillates have given good re-
sults. The high market price of montan wax in comparison to
asphalt undoubtedly accounts for this.

METHODS OF STORAGE

Bituminous substances which are capable of liquefying under
heat are usually stored in metal tanks of various capacities. These
may be equipped with steam-coils. One device consists in con-
structing a small metal tank within a larger one, the smaller unit
being provided w r ith the steam coils to conserve the heat. 87

CHAPTER VII

MINERAL WAXES

OZOKERITE

Ozokerite is a native mineral wax, composed of the higher mem-
bers of the C n H 2 n + 2, and C n H 2 n series of hydrocarbons. It occurs
in deposits usually associated with petroleum. Certain varieties
carry a proportion of petroleum in solution with the wax, and the
more petroleum present, the softer will be the consistency and lower
the fusing-point. Ozokerite as ordinarily found is fairly hard, and
has a comparatively high fusing-point, ranging from 50 to 180 F.
The fusing-point has been recorded as high as 200 F. (K. and S.
method). Ozokerite containing between 10 and 15 per cent of
petroleum in solution, shows a fusing-point between 140 and 150 F.
The petroleum can readily be evaporated by applying a moderate
degree of heat, and is expelled during the refining process.

The color of ozokerite depends upon the nature and extent of
the impurities present, and ranges from a transparent yellow to a
dark brown. In rare instances, ozokerite occurs in a dichroic va-
riety, showing a dark green color by reflected light, and a pure
yellow by transmitted light. It breaks with a conchoidal fracture,
and has a characteristic waxy lustre. Its streak on porcelain varies
from a transparent white to a pale brown.

Ozokerite is usually found filling veins or fissures, which are
very irregular in structure, varying from a fraction of an inch to
about two feet in thickness. Some extend for comparatively long
distances whereas others pinch out very suddenly. The veins are
usually caused by faulting, which accounts for their irregularity and
gives the vein the appearance of a series of pockets. The indica-
tions are that the ozokerite enters the faults or veins from below,
which is borne out by the fact that the material mined at a depth
is materially softer and has a lower fusing-point than that obtained
near the surface.

Ozokerite may occur in a pure state (comparatively free from

129

130 MINERAL WAXES VII

mineral matter), which proves to be the case when it is found in
vein form, or it may be associated with sandstone or shale. In
fact, it is quite common for the entire region surrounding the vein
to be saturated with ozokerite.

A paraffinaceous petroleum almost invariably occurs in the strata
underlying the ozokerite, which would seem to indicate that the
latter must have been produced by the slow hardening and probably
also the oxidation of petroleum throughout centuries of time.
Ozokerite, itself, however, is practically free from oxygen. In this
particular case, therefore, the effect of oxidation is to eliminate
hydrogen, and form hydrocarbons of higher molecular weight.

The petroleum underlying the ozokerite usually contains from
8 to 1 2 per cent of paraffin, which, however, is entirely different in
its character from the hydrocarbons contained in the ozokerite. 1
This proves conclusively that ozokerite is not formed merely by the
evaporation of petroleum, but must have been produced by a process
of metamorphosis or polymerization.

On distilling at atmospheric pressure, ozokerite decomposes,
whereas when it is distilled under reduced pressure, its composition
changes but little. Still another process consists in distilling the
ozokerite in retorts with superheated steam, whereupon the residue
in the retort is known as 44 ozokerite pitch," which when combined
with rubber has been marketed under the name "okonite."

Ozokerite as it is mined is assorted by hand-picking to separate
the pure material from that associated with earthy matter. The
latter, which is known as "wax-stone," is broken up to remove any
lumps of rock and purified by extraction with boiling water. The
method used for this purpose is very crude, and consists merely in
boiling the wax-stone with water in large open kettles. The sand-
stone or shale separates to the bottom and the melted ozokerite
floats in a layer on the surface, whereupon it is skimmed off, boiled
to evaporate the water and cast into blocks. The commercial ma-
terial is comparatively free from mineral matter, rarely containing
over 2 per cent.

Ozokerite may be refined still further by heating to 120-200 C.,
with 20 per cent by weight of concentrated sulfuric acid, or with
chromic acid, 2 or by treating ozokerite with alkali and filtering hot
through fuller's earth, animal charcoal, or magnesium silicate. This

VII OZOKERITE 131

bleaches the ozokerite, forming a product almost white in color,
known as "ceresine." From 10 to 15 per cent of the ozokerite is
lost during the treatment, but the fusing-point of the product is
increased. The final traces of acid are removed and the bleaching
process completed by adding from 5 to 12 per cent of dry residue
obtained from the manufacture of "ferrocyanides." The main dif-
ferences between ozokerite and ceresine are in the color and
fusing-point.

Ozokerite and ceresine are used in the manufacture of high-
grade candles, colored lead pencils, for finishing off the heels and
soles of shoes, manufacturing shoe polishes, electrical insulating
purposes, as an acid-proof coating for electrotypers* plates, and
waxing floors. They are readily soluble in turpentine, petroleum
distillates, carbon disulfide, and benzol, by scarcely soluble in alcohol.

Purified ozokerite and ceresine comply with the following
characteristics :

(Test i)* Color in mass White to yellow to brown

(Test 4) Fracture Conchoidal

(Test 5) Lustre Dull to "waxy"

(Test 6) Streak Transparent white to yellow

(Test 7) Specific gravity at 77 F o. 85-1.00

(Test go) Hardness, Moh's scale Less than i

(Test 9^) Penetration at 32 F o

Penetration at 77 F 20-30

Penetration at 115 F 150-250

(Test $c) Consistometer hardness at 32 F. . . Above 100

Consistometer hardness at 77 F . . . 20-40

Consistometer hardness at 115 F. . . 5-15

(Test gd) Susceptibility factor Greater than 80

(Test i$a) Fusing-point (K. and S. method) 140-200 F.

(Test 15^) Fusing-point (R. and B. method). . . . 155-225 F.

(Test 19) Fixed carbon K-IO per cent

(Test 21) Soluble in carbon disulfide 95-100 per cent

Non-mineral matter insoluble * . o-i per cent

Mineral matter 0-5 per cent

(Test 22) Carbenes 0-3 per cent

(Test 23) Non-mineral matter soluble in 88

petroleum naphtha 75~95 per cent

(Test 26) Carbon 84-86 per cent

(Test 27) Hydrogen. . . < 16-14 per cent

(Test 28) Sulfur o-i . 5 per cent

(Test 29) Nitrogen 0.0.5 per cent

(Test 30) Oxygen 0-2 percent

(Test 33) Solid paraffins 50-90 percent

(Test 34^) Sulfonation residue 90-100 per cent

(Test 37*) Saponifiable constituents 0-2 per cent

* The numbers refer to tests, which are described in detail in Chapter XXXII.

132 MINERAL WAXES VII

Very often ozokerite and ceresine are adulterated with paraffin
wax, rosin, tallow, stearic acid or mineral fillers (such as talc, kao-
lin, gypsum, etc. ) *

Ozokerite occurs in the following localities : 8

EUROPE

Poland (Galicia). 4 The most important ozokerite deposits are
found in the Carpathian Mountains in the districts of Drohobycz
(comprising Boryslaw, Wolanka and Truskawiec) and Stanislau
(comprising Dwiniacz, Straunia, Wolotkow and Niebylow). It is
known under various names, e.g., "ozokerit," "fossil or montan
wax," "mineral fat," etc. In the Moldau region it is called "zietris-
zit," and around the Caspian Sea, "nephtgil," "neftgil," "naphatil,"
etc. The largest deposit is located as Boryslaw, a small town in
Galicia, and has been exploited since about 1859. ^ ' IS found at
some depths below the surface, associated with schist and sand-
stone, and it is mined by means of shafts and galleries. About
1500 shafts have been sunk in the district.

The following varieties of ozokerite are recognized in the
Boryslaw district:

(1) Marble wax, found 100200 m. below the surface, is very
hard, of a pale yellow color, with greenish, brownish and black
markings, giving it the appearance of marble, and has a fusing-
point of 85 to 1 00 C.

(2) Hard wax or "crackwax" (Sprungwax) is darker in color
than marble wax, shows a granular fracture and a fusing-point of
75 to 90 C.

(3) Fibrous wax, or "fibrewax," which is characterized by its
fibrous structure.

(4) Bagga is dark in color, contains clay, and has a compara-
tively low fusing-point (40-60 C.).

(5) Kindebal or "kinderball" is characterized by being soft, of
low fusing-point (30-50 C.) and a black color. It contains pe-
troleum and mineral matter.

(6) Blower wax ("blister wax" or "matka") is a pale yellow,
soft variety, which is squeezed out of the veins due to the presence
of the surrounding rocks.

(7) Lep is a variety of ozokerite associated with a substantial
proportion of mineral matter.

The deposit at Wolanka is smaller than that at Boryslaw. The

VII EUROPE 133

occurrence at Truskawiec differs from the others by the presence of
a comparatively large percentage of sulfur. The ozokerite in this
locality is associated with native sulfur, lead sulfide, gypsum, and
petroleum.

At Dwiniacz, Straunia and Wolotkpw, about 70 miles south of
Boryslaw, the ozokerite veins are located some distance below the
surface, in beds of clay between layers of shale. Considerable
ozokerite has been mined in this district, and particularly at
Dwiniacz. The veins vary in size from J4 * n - to about I ft. The
rock in the vicinity of the veins is impregnated with wax, contain-
ing an average of 2 per cent.

Rumania. Deposits of ozokerite are also found in a spur of the
Carpathian Mountains in the province of Moldavia in Rumania. It
has been mined in several localities, the largest vein occurring in the
city of Slanik, beneath a bed of bituminous shale, associated with a
vein of cannel coal. This deposit is characterized by its high fusing-
point, in the neighborhood of 200 F. (K. and S. method).

Russia. Numerous deposits of ozokerite occur throughout
Russia, including specifically the following: 5

Terek Province (Northern Caucasia}. In thq vicinity of Gro-
zny!, among the narrow passes along the road from Wozdwishensk
and Chatoi, near the right bank of the Chanti-argun River.

Kuban Province* (Northern Caucasia] . In the oil fields at Mai-
kop, near Chadychenskaja, on so-called Wax Mountain, about 5 km.
from Pshish stream.

Kutais Province (Transcaucasia}. In the vicinity of Kutais, 2
km. east of the village Dznucisi, between the rivers Lechidary and
Merchery; likewise at Achokrua in the same neighborhood; also
near Charopan, northeast of the village Tedeleti, in a gorge be-
tween the mountains Gagberula and Syrch-Liberta.

Tiflis Province (Transcaucasia}. At Sadzluri, in the neighbor-
hood of Cori, on the banks of Kran River.

Baku Province (Transcaucasia}. In the Baku oil fields, near
the town Surachany, also on the Island of Suyatoi in the Cas-
pian Sea.

Kars Province (Transcaucasia}. In the region of Chala-Da-
rasi, in the vicinity of Kars. Occurs in layers containing 1.5 to 2.5
per cent ozokerite in Uzbekistan, at Sel-rokho and Shorsu.

134 MINERAL WAXES VII

ASIA

State of Turkestan. On the Island of Cheleken in the Caspian
Sea; 6 also in the vicinity of Ferghana, also at Neftedag (Turkoman
Republic) in veins containing 50 to 80 per cent ozokerite, termed
locally "lep."

Siberia. Along the eastern shore of Lake Baikal.

Philippine Islands. On the Island of Leyete, veins of ozokerite
occur at the contact of an intrusive dike with shales and sand-
stones. 7

NORTH AMERICA

UNITED STATES

Utah. The most important deposit occurs near Colton, in
Wasatch County, Utah, 8 *in a bed of oil shale. The veins extend
from about 2 miles west of Colton to within a few hundred yards
west of the railroad station of Soldier Summit, or a total distance of
12 miles. The mineral as mined contains about 15 per cent ozo-
kerite which is extracted by heating the crushed ore with water at
60*70 C, whereupon the wax floats off. A peculiar feature of this
deposit is the occurrence of fossil shells together with other animal
remains. The following analytical results have been reported:

(Test i) Color in mass Yellowish brown

(Test 4) Fracture Conchoidal

(Test 5) Lustre Dull

(Test 6) Streak Pale yellow

(Test 7) Specific gravity at 77 F o. 899-0. 920

(Test 9*) Hardness, Moh's scale Less than i

(Test gb) Penetration at 77 F 30

Penetration (100 g., 15 sees.):

at 20 C 0.43 mm.

at 30 C 0.64 mm.

at 40 C i . 27 mm.

at 50 C 2.2 mm,

at6oC 3.8 mm.

(Test 111) Coefficient of expansion between 10 and

50 C., per deg. C o.ooi

(Test I5/) Fusjng-point 60 to 80 C

(Test 16) Volatile, 212 F. I hr o.o per cent

Volatile, 325 F., 5 hrs 45.41 per cent

Volatile, 400 F., 5 hrs 65.2 per cent

(Test 19) Fixed carbon 9.6 per cent

(Test 21 ) Solubility in carbon disulfide 99.46 per cent

Non-mineral matter insoluble o. 50 per cent

Free mineral matter 0.046 per cent

VII NORTH AMERICA 135

(Test 12) Carbcnes 2. 51 per cent

(Test 23) Soluble in 88 petroleum naphtha 81 .71 per cent

(Test 26) Carbon 85.35 P er cent

(Test 27) Hydrogen 13.86 per cent

(Test 28) Sulfur 0.29 per cent

(Test 29) Nitrogen 0.36 per cent

(Test 58) Dielectric strength across a o.i-in. gap over 30,000 volts

Dielectric constant 2 .03

Power factor o . 03

Resistivity across a i-cm. cube 30 million megohms

Texas. At Thrall, in the so-called Thrall Oil Field, another
deposit has been reported. 9 The crude material is soft, due to the
petroleum associated with it, and of a dark brown color. It has a
strong odor of petroleum, and a specific gravity at 77 F. of 0.875.
On being heated to 100 C, it loses 14.72 per cent, and at 180 C.
a total of 23. 1 4 per cent in weight. On being freed from petroleum,
it shows a fusing-point of 175 F.

HATCHETTITE OR HATCHETTINE

The above names are assigned to a soft variety of ozokerite
fusing in the neighborhood of 120 F. (Test I5/). It varies in
specific gravity from 0.90 to 0.98 at 77 F., and has a yellowish-
white> yellow or greenish-yellow color. It was named after C,
Hatchett, an English chemist (1765-1847). It is found near
Merthyr-Tydvil in Glamorganshire, England, also at Loch Fyne in
Argylshire, Scotland.

SCHEERERITE

A native wax found in a bed of lignite near St. Gall, Switzer-
land. It occurs in the form of crystals (monoclinic) and of a white,
gray, yellow, green or pale reddish color. It is more or less trans-
lucent to transparent, and has a waxy feel. It is composed chiefly
of the members of the paraffin series, and fuses at a temperature
of 110-115 F.

KABAITE

This is a waxy hydrocarbon similar to ozokerite or scheererite,
which has been found in meteorites. It is only of scientific interest
and has no commercial importance.

136 MINERAL WAXES VII

MONTAN WAX

As stated previously, montan wax is dissolved from certain non-
asphaltic pyrobitumens by means of volatile solvents, such as benzol,
xylol, mixtures of benzol with methyl alcohol or acetone, 10 mixtures
of toluol and alcohol, 11 etc. By extracting under pressure the yield
is materially increased, and at 50 atmospheres at 250-260 C.,
benzol will extract about double the weight than at I atmosphere
at 80 C. 12 The lignite or pyropissite is first dried, then granu-
lated, and finally extracted. The extract is evaporated to recover
most of the solvent. The last traces of solvent are expelled from
the montan wax by distillation with steam, and recondensed. The
crude wax differs widely according to the source, Thuringian lignites
yielding a hard and brittle wax, whereas Bohemian lignites yield a
softer product.

Ninety per cent of the montan wax present in the lignite is re-
moved in this manner. About 10 to 15 per cent of the solvent is
lost, but the high price obtainable for montan wax renders this per-
missible. Usually 8 to 10 per cent of montan wax is extracted
from Thuringian lignite based on the dry weight of the latter. In
exceptional cases, as high as 20 per cent has been obtained. Pyro-
pissite yields between 50 and 70 per cent of montan wax based on
its dry weight. Unfortunately, the supply of pyropissite is largely
exhausted.

According to Edmund Graefe, 13 the following percentages of
montan wax are extracted by benzol from the dried minerals :

Per Cent

Bohemian Lignite i 29

Texas Lignite 2.07

Lignite from the region of the Rhine 4-7

Lignite from Vladivostok 5-3&

Lignite from Thuringia, Saxony 9-3

Pyropissite 69. 50

The montan wax industry is not practiced in the United States,
but is localized in Saxony.

Montan wax contains esters of acids possessing high molecular
weight, free acids and a small quantity of substances containing sul-
fur. Various formulae have been assigned to it, including Ci e H 82 O,
CHO2 C 2 0H 5 8O and C^HgeO.

VII NORTH AMERICA 137

At ordinary temperatures it decomposes when distilled. It may,
however, be purified by distilling with superheated steam in
In this manner the following products are obtained :

Pure odorless montan acid;

Refined montan wax;

A bright yellow wax containing paraffin;

(4) A residue containing paraffin;

(5) An acid-free pitch, 15 known as "montanpitch" or "montan-
wax pitch," which is a hard waxy material having a dark color.

On heating with glycerine, an ester is obtained which has a
much higher fusing-point (in the neighborhood of 200 F.). Mon-
tan wax may be blown with air, either alone or in the presence of
oxalic acid, 16 and when chlorinated will be transformed into a resi-
nous product. 17

Commercial montan wax complies with the following charac-
teristics :

(Test i) Color in mass;

Crude montan wax Dark brown

Product obtained by distillation in

vacuo Almost white

(Test 4) Fracture Conchoidal

(Test 5) Lustre Waxy

(Test 6) Streak on porcelain Yellowish brown to white

(Test 7) Specific gravity at 77 F o. 90-1 .00

(Test 9^) Penetration at 77 F o to 5

(Test 9<r) Hardness at 77 F. (consistometer) Above 100

(Test $d) Susceptibility index > 100

(Test 10) Ductility at 77 F o.o

(Test I5/) Fusing-point (K. and S. method) 170-200 F.

Note. Montan wax obtained from pyropissite has a higher fusing-point than
that obtained from lignite; namely, between 190 and 200 F.

(Test 17) Flash-point 55 to 575 F.

(Test 19) Fixed carbon 2-10 per cent

(Test 21) Solubility in carbon disulfide Greater than 98 per cent

Non-mineral matter insoluble 0-2 per cent

Mineral matter Less than 2 per cent

(Test 23) Soluble in 88 petroleum naphtha 80-100 percent

(Test 26) Carbon 82-83^ per cent

(Test 27) Hydrogen *4~ I 4# per cent

(Test 28) Sulfur Less than i . 5 per cent

(Test 29) Nitrogen Trace

(Test3o) Oxygen 3~6 percent

(Test 33) Solid paraffins , o-io per cent

(Test 34^) Sulfonation residue *. . o-io per cent

(Test 370) Acid value '. 28-33

(Test 37*) Ester value 28-73

138 MINERAL WAXES VII

(Test 37<f) Saponification value 5~95

(Test 37<r) Saponifiable matter 50-80 per cent

Resins 20-30 per cent

Alcohols 5-20 per cent

Normal wax acids 49~5^K per cent

Oxy-acids 3-5 per cent

Sulfur-containing acids 6^-8 per cent

(characteristic of crude montan wax)

(Test 38) Asphaltic constituents o per cent

(Test 39) Diazo reaction No

(Test 40) Anthraquinone reaction No

Montan wax is used for manufacturing shoe polishes, phono-
graphic records, electrical insulating materials, and the like, also
for impregnating timber under vacuum followed by pressure. 1

CHAPTER VIII

NATIVE ASPHALTS OCCURRING IN A FAIRLY
PURE STATE

Under this heading will be considered the most important as-
phalt deposits containing less than 10 per cent of mineral matter
figured on the dry weight. These include exudations or seepages of
liquid or semi-liquid asphalts, also surface overflows and lakes.
Most of these are characterized by being liquid to semi-liquid at
normal atmospheric temperature, and by containing a comparatively
large proportion of volatile matter. Only a few of these deposits
are of value commercially.

The principal deposits are as follows :

NORTH AMERICA

UNITED STATES
Kentucky.

Breckinridge County. The so-called "Tar Springs" situated
about 4 miles south of Cloverport on Tar Creek, have been known
for many years. They occur as seepages of pure, soft asphalt at
the base of an overhanging cliff of sandstone where it joins a
stratum of limestone. The asphalt is accompanied by water charged
with sulfur compounds, and the surrounding rocks abound in ma-
rine fossils.

Gray son County. Similar seepages abound along Big Clifty
Creek and its tributaries, in the vicinity of Grayson Springs station.
Some exude from sandstone and others from clay or shale. The
seepages carry between 5 and 10 per cent of free mineral matter,
the balance consisting of a very soft, "stringy" asphalt containing a
large proportion of volatile ingredients and yielding about 15 per
cent of fixed carbon.

139

140 NATIVE ASPHALTS OCCURRING IN FAIRLY PURE STATE VIII

Oklahoma.

There are only a few minor occurrences of pure asphalt found
in Oklahoma in the form of seepages, including the following:

Carter County. NE J4, Sec. 10, T 2 S, R 2 W; 10 miles north
of Wheeler.

Murray County. SW J4, SE ^4, Sec. 15, T i S, R 3 E; 3
miles south of Sulphur.

Neither of these has any commercial importance.

Utah.

Uinta County. A pure, solid asphalt is found in Tabby Can-
yon, a branch of the Duchesne River, 8 to 9 miles south and west
of the town of Theodore and about 30 miles west of Ft. Duchesne.
It has been exploited under the name "tabbyite" * and tests as
follows :

(Test 4) Fracture Conchoidal

(Test 5) Lustre Bright

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i .006-1 .010

(Test 90) Hardness, Moh's scale Less than i

(Test 9^) Penetration at 77 F o

(Test 9<r) Consistency at 77 F 80.0

(Test i$a) Fusing-point (K. and S. method) 178 F.

(Test 1 6) Volatile matter, 325 F. in 5 hrs 2.78 per cent

Volatile matter, 400 F. in 5 hrs 6.40 per cent

(Test 19) Fixed carbon 8 .08- 9 . 2 per cent

(Test 21 ) Soluble in carbon disulfide 94.7 -92. i per cent

Non-mineral matter insoluble 0.5-1.1 per cent

Free mineral matter 4.8-6.8 per cent

(Test 22) Carbenes o.o per cent

(Test 23) Soluble in 88 petroleum naphtha 61 per cent

(Test 25) Carbon 82 per cent

(Test 26) Hydrogen n per cent

(Test 27) Sulfur 2 per cent

(Test 28) Nitrogen 2-2.5 per cent

Undetermined 2 per cent

Boxelder County. .A pure viscous asphalt deposit occurs below
the bed of Great Salt Lake, about 10 miles south of Rozel, in the
Promontory Range. 2 It is found in a series of horizontal veins 3
to 5 ft. thick interposed between beds of clay, continuing to a depth
of at least 140 ft. It is highly probable that a lake of asphalt
occurred at this point centuries ago, which in time became covered
with sediments, giving rise to a series of veins.

VIII NORTH AMERICA 141

At the present time, masses of asphalt exude through the uncon-
solidated material at the bottom of the lake, and float to the sur-
face in lumps i to 2 ft. in diameter. This occurrence corresponds
very closely with the Dead Sea deposit. On analysis, the asphalt
tests as follows:

(Test 5) Lustre Very bright

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F 1 .02

(Test gb) Penetration at 32 F. (200 g. in 60 sees.) 12

Penetration at 77 F. (100 g. in 5 sees.) 50

Penetration at 115 F. (50 g. in 5 sees.) 170

(Test loo) Ductility at 77 F 70 cms.

(Test 16) Volatile at 325 F. in 5 hrs 2.33 per cent

Volatile at 325 F. in 7 hrs . . . . 3.4 per cent

(Test 19) Fixed carbon 4. 56 per cent

(Test 21 ) Soluble in carbon disulfide 95 .00 per cent

Non-mineral matter insoluble i . 84 per cent

Free mineral matter 3.16 per cent

Note. Has unusually high adhesiveness, ductility and cementing qualities. >

California.

Kern County. Deposits of asphalt occur in the so-called "As-
phalto Region" in the western part of Kern County, about 50
miles west of Bakersfield, in the form of large springs; also as
veins. The character of the asphalt varies greatly, both in consis-
tency and purity. The superficial overflow covers an area of 7
acres, in a layer 2 to 4 ft. thick overlying sand and clay. Part of it
has hardened on account of exposure to the elements, and other
portions are still soft and viscous. A vein of asphalt also occurs in
the vicinity of the overflow, filling a fault, varying from 2 to 8 ft.
in width, averaging about 4 ft. The nature of the asphalt in the
vein is similar to that of the overflow.

The asphalt carries from 3 to 30 per cent mineral matter,
mostly sand and clay, also gas, which is evidenced by the fact that
it loses between 5 and 15 per cent in weight on being heated to
212 F. for one hour. The run of the mine averages 85 per cent
asphalt, 10 per cent mineral matter and 5 per cent moisture and
gas. It is refined by heating, which drives off the water and gas
and permits a certain amount of the mineral matter to settle out.
According to Clifford Richardson 8 the refined asphalt tests as
follows :

142 NATIVE ASPHALTS OCCURRING IN FAIRLY PURE STATE VIII

(Test 4) Fracture Semi-conchoidal

(Test 5) Lustre Bright to dull

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i .06

(Test 9^) Penetration at 77 F 0-27

(Test 1 6) Volatile matter, 325 F., 5 hrs 6.6 per cent

Volatile matter, 400 F., 5 hrs 19.9 per cent

(Test 19) Fixed carbon 8.0 per cent

(Test 21) Soluble in carbon disulfide 89.8 per cent

Non-mineral matter insoluble 3.4 per cent

Free mineral matter 6.8 per cent

Total 100.0 per cent

(Test 22) Carbenes 0.3 per cent

(Test 23) Soluble in 88 petroleum naphtha 53 .4 per cent

(Test 340) Saturated hydrocarbons 28 .6 per cent

The asphalt resembles gilsonite in its outward appearance, but
is considerably softer, yielding a smaller percentage of fixed carbon.
Richardson infers that the asphalt has been metamorphized only
part way to gilsonite. This deposit of asphalt is not being worked
at the present time, but is of interest from the scientific viewpoint.

A sample of liquid asphalt taken from seepages in the so-called
"McKittrick Region," in Kern County, shows specific gravity at
77 F. of 0.99, and 16 per cent loss on being heated to 400 F. for
seven hours. In its original state it is very soft and sticky.

San Luis Obispo County. A large surface deposit of soft asphalt
produced by seepage from the surrounding shale occurs at Tar
Spring Creek, a tributary of the Arroyo Grande, 20 miles southeast
of San Luis Obispo, covering an area of 200 ft. in diameter and
3-15 ft. deep. As it exudes from the shale, the asphalt is soft and
accompanied with sulfurous water; near the edge of the deposit it
appears quite hard, and at the edge it verges towards brittleness.
No analytical results are available.

Santa Barbara County. Veins of high-grade asphalt occur in
La Graciosa hills about 4 to 5 miles east of the town of Graciosa in
the so-called Santa Maria Region. These are irregular in forma-
tion, extending through shale and sandstone, and varying from
several inches to 2 ft. in width. Associated with these veins are beds
of impregnated asphaltic shale, extending over an area of a mile or
two, and containing a variable percentage of asphalt. One of the
striking features of these Recurrences is the presence of marine
fossils in the veins and surrounding shale, indicating that the asphalt
is of animal origin^

VIII NORTH AMERICA 143

Oregon.

Coos County. An unusual type of asphalt occurring in beds of
coal has been reported at the old Newport Mine at Libby, and old
Ferrey's Mine at Riverton, in the Coos Bay coal field. It is hard
and brittle, and similar to coal in appearance. About one-third of
the non-mineral matter is insoluble in carbon disulfide, yet the ma-
terial fuses as a comparatively low temperature (about 300 F.),
and has a specific gravity of less than i.io at 77 F. It may be re-
garded as a metamorphized asphalt or a glance pitch. It consti-
tutes one of those substances encountered occasionally, falling on the
border line, so that it becomes a difficult matter to arrive at its cor-
rect classification. For a long time it was known as a "Pitch
Coal." 4 The following data would seem to indicate that it par-
takes of the properties of an asphalt rather than of a glance pitch:

(Test 4) Fracture Hackly to conchoidal

(Test 5) Lustre Fairly dull to brilliant

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F 1 .09 to i . 28

(Test 9*) Hardness, Moh's Scale About I

(Test 9^) Penetration at 77 F o

(Test 9f) Consistency at 77 F Above 100

(Test 14^) In flame Softens and flows

(Test i$a) Fusing-point (K. and S. method) 302 to 330 F.

(Test 16) Volatile at 325 F., 5 hrs o. 5 per cent

(Test 19) Fixed carbon 10-13 per cent

(Test 21) Soluble in carbon disulfide 100 per cent

(Test 22) Carbenes o per cent

(Test 23) Soluble in 88 petroleum naphtha About 10 per cent

(Test 27) Sulfur o. 5-1 .o per cent

MEXICO
State of Tamaulipas.

Asphalt springs occur at numerous points along the Tamesi
River, which, according to Clifford Richardson, 5 show the follow-
ing characteristics :

(Test 7) Specific gravity at 77 F i .04-1 . 12

(Test 9*) Penetration at 77 F 40-16

(Test 16) Loss at 212 F. until dry 10-20 per cent

Loss at 325 F. for 5 hrs. (refined material). . . i . 5-4. 8 per cent

Loss at 400 F. for 5 hrs 4.3-8.9 per cent

(Test 17) Flash-point 308 F.

(Test 19) Fixed carbon 12.6-16. i per cent

(Test 21) Solubility in carbon disulfide (refined material). 89. 0-99 . o per cent

Non-mineral matter insoluble o. 5- i . 8 per cent

Free mineral matter 0.5-9.1 per cent

144 NATIVE ASPHALTS OCCURRING IN FAIRLY PURE STATE VIII

Other deposits in the neighborhood show a larger proportion of
mineral matter, often running as high as 33 per cent

Chijol. Asphalt springs occur also near Chijol, 25 miles west
of Tampico. They are comparatively soft in consistency, testing
over 90 per cent soluble in carbon disulfide, with less than 10 per
cent mineral matter,

State of Vera Cruz.

District of Tuxpan. Similar deposits are found in the neigh-
borhood of Tuxpan, some distance from the Tuxpan River, having
the same general characteristics as the preceding. Analyses show
that 90 per cent is soluble in carbon disulfide, with less than 10 per
cent of mineral matter.

District of Chapapote. Similar deposits are found 15 miles
from Timberdar at the head of the Tuxpan River, of an exceed-
ingly pure character, testing 99 per cent soluble in carbon disulfide,
and less than i per cent mineral matter. The asphalt varies in
consistency from a semi-liquid to a comparatively hard solid, de-
pending upon the length of time it has been exposed to the weather. 6

In the early days, the name "chapapote" was applied generally
to designate viscous, semi-liquid asphalts corresponding in charac-
teristics to the type of asphalt found in this district

CUBA

Province of Matanzas. A pit filled with pure liquid asphalt
has been reported in the neighborhood of Santa Catalina. This
occurs in a bed of serpentine, and originally produced in the neigh-
borhood of 20 barrels of semi-liquid asphalt a day, derived pre-
sumably from underlying petroleum-bearing strata. Other pits in
the neighborhood similarly yield liquid asphalt

Liquid asphalt is also found near Cardenas and extends some
distance eastwards. Another deposit, known as "Dos Companeros
Mine," occurs in the Guametos District, near Sabanilla de la Palma,
testing as follows :

(Test 7) Specific gravity at 77 F 1.05-1.06

(Test 16) Volatile at 220 F 2-18 per cent

Volatile at 325 F., 5 hrs 2.8-6.8 per cent

VIII NORTH AMERICA 145

(Test 19) Fixed carbon 10-12 per cent

(Test 21) Soluble in carbon disulfide 98-99 per cent

Non-mineral matter insoluble o-i . 5 per cent

Mineral matter 0.5-2.0 per cent

(Test 23) Soluble in 88 petroleum naphtha 73-77 per cent

Another deposit occurs 7 miles south of Hato Nuevo, testing
similar to the preceding. All of these deposits contain more or
less adventitious water.

Province of Santa Clara. A variety of hard asphalt, ap-
proaching glance pitch, is found in Calabazar District, near the
town of Mata, in a mine known as "El Provenir." It tests as
follows : 7

(Test i) Color in mass Black

(Test 4) Fracture Conchoidal

(Test 5) Lustre Bright

(Test 6) Streak on porcelain Brownish black

(Test 7) Specific gravity at 77 F i .09-1 .11

(Test 19) Fixed carbon 18 .o- 19.2 per cent

(Test 21) Soluble in carbon disulfide 97 . 5- 97 . 6 per cent

Non-mineral matter insoluble 0.5- 0.9 per cent

Mineral matter 2.0- i . 5 per cent

Total '. 100.0-100.0 per cent

(Test 23) Soluble in 88 petroleum naphtha 39. 4- 57.4 per cent

Province of Camaguey. Deposits of pure soft asphalt occur
near the village of Minas, about 30 miles from Nuevitas and 20
miles from Puerto Principe City. The asphalt is associated with
water, and tests as follows:

(Test 7) Specific gravity at 77 F. (dry) , i .079

(Test gb) Hardness at 77 F. (dry) 35

(Test 16) Volatile at 325 F. in 5 hrs 6.2 per cent

Penetration of residue at 77 F 12

(Test 21) Soluble in carbon disulfide 94- 5 per cent

Non-mineral matter insoluble 0.3 per cent

Mineral matter 5.2 per cent

Total 100. o per cent

(Test 23) Soluble in 88 petroleum naphtha 70.0 per cent

Province of Santiago de Cuba* A small deposit of soft as-
phalt has been reported in Victoria de las Tunas District, $ l /2 miles

146 NATIVE ASPHALTS OCCURRING IN FAIRLY PURE STATE VIII

southwest of San Manuel, in a mine known as "Punta la Brea,"
which tests as follows :

(Test 7) Specific gravity at 77 F o. 990

(Test 16) Volatile at 325 F. in 5 hrs 6.3 per cent

(Test 21) Soluble in carbon disulfide 99. 1 per cent

Non-mineral matter insoluble 0.5 per cent

Mineral matter 0.4 per cent

(Test 23) Soluble in 88 petroleum naphtha 88 . 8 per cent

SOUTH AMERICA

VENEZUELA

State of Bermudez. The so-called Bermudez "Pitch Lake" 8
is situated near the town of Guanoco in the District of Benitez, 3
miles above the confluence of the San Juan and Guanoco Rivers, 25
miles west of the Gulf of Paria, and 105 miles due west of Trinidad
Lake. It is covered with vegetation and water in pools. A typical
view is shown in Fig. 43. The lake represents the exudation of soft
asphalt from springs distributed at different points over its area, and
constitutes one of the largest deposits of pure asphalt yet discov-
ered, extending over mo acres and varying in depth from 2 to
20 ft, averaging 5 ft.

Its consistency varies in different parts of the lake. Where it
exudes from the springs, it is quite soft, and disengages gas freely
and copiously. The surface of the deposit hardens slowly on expo-
sure to the weather, forming a crust varying from several inches to
several feet in thickness, and sufficiently firm to support the weight
of a man. The asphalt underneath, however, is still soft and semi-
liquid, and there are numerous breaks through the surface from
which the soft asphalt oozes. At the edge of the lake the asphalt
is hard and brittle, due to the evaporation of the volatile constitu-
ents by the heat of the sun. Certain portions of the lake have been
converted into a cokey mass as a result of fires which must have
swept over the lake years ago, due probably to the combustion of
vegetation growing profusely at the edges.

To remove the asphalt, a dam is built of slag and waste and

VIII

SOUTH AMERICA

147

Courtesy of Barber Co.

FIG. 43. -View of Bermudez Asphalt Lake.

Courtesy of Barber Co.
FlG. 44. Transporting Bermudez Asphalt.

148 NATIVE ASPHALTS OCCURRING IN FAIRLY PURE STATE VIII

the water pumped out The asphalt is then dug out by hand and
loaded into small cars, which are hauled by cable to a railroad run-
ning to Guanoco, 8 miles distant, where it is either refined or run
directly to a loading jetty, whence it is transferred to steamers as
shown in Fig. 44,

The crude asphalt has the following composition : 9

(Test 21) Soluble in carbon disulfide 64.39 per cent

Non-mineral matter insoluble 3 . 53 per cent

Mineral matter 2 .08 per cent

(Test 25) Water 30.00 per cent

Total 100.00 per cent

According to Clifford Richardson, 10 the dried crude Bermudez
asphalt has the following composition :

(Test i) Color in mass Black

(Test 4) Fracture Conchoidal

(Test 5) Lustre Bright

(Test 7) Specific gravity at 77 F i .05-1 .075

(Test 16) Volatile at 400 F. in 5 hrs. (dried material). . 5.81-16.05 per cent

(Test 21 ) Soluble in carbon disulfide 90-98 per cent

Non-mineral matter insoluble o . 62-6 . 45 per cent

Free mirteral matter o. 50-3 . 65 per cent

The crude Bermudez asphalt is melted to drive off the moisture
and gas. The water which is present is derived from the heavy
rains and by overflows from the surrounding country. It is not
emulsified with the asphalt as is the case with the Trinidad deposit.
The percentage of water varies from 10 to about 40 per cent as a
maximum.

Refined Bermudez asphalt tests as follows: 11

(Test 4) Fracture ; Conchoidal

(Test 5) Lustre Very bright

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i .06-1 .085

(Test ga) Hardness on Moh's scale Less than i

(Test 9^) Penetration at 1 15 F 60

Penetration at 77 F 20-30

Penetration at 32 F 3

(Test 9*) Consistency at 115 F , 7.7

Consistency at 77 F . 22. 7

Consistency at 32 F 93. 8

(Test 9<J) Susceptibility index 62. 5

VIII SOUTH AMERICA 149

(Test io) Ductility at 115 F ....................... 14.5

Ductility at 77 F ........................ u

Ductility at 32 F ........................ o

(Test n) Tensile strength at 115 F ................. 0.60

Tensile strength at 77 F .................. 3.45

Tensile strength at 32 F .................. 10, 5

(Test 15*) Fusing-point (K. and S. method) ........... 130-140 F.

(Test 15*) Fusing-point (R. and B. method) ........... 145-160 F.

(Test 16) Volatile matter, 325 F., 5 hrs .............. 3.0- 6.0 per cent

Volatile matter, 500 F., 5 hrs .............. 8 .0-10.0 per cent

(Test 19) Fixed carbon ............................. 12.9-14.0 per cent

(Test 21) Solubility in carbon disulfide ............... 92-97 per cent

Non-mineral matter insoluble .............. i . 5-4.0 per cent

Free mineral matter ...................... i . 5-6. 5 per cent

(Test 22) Carbenes ____ . ........................... o.o-i .o per cent

(Test 23) Solubility in 88 petroleum naphtha ........ 60-75 per cent

(Test 26) Carbon ................................. 82.88 per cent

(Test 27) Hydrogen ............................... 10.79 per cent

(Test 28) Sulfur ................................... 5.87 per cent

(Test 29) Nitrogen ................................ 0.75 per cent

Total ............................... 100. 29 per cent

(Test 33) Solid paraffins ........................... Trace

(Test 340) Saturated hydrocarbons ................... 23-25 per cent

(Test yjd) Saponification value ...................... 28 . o per cent

(Test 380) Free asphaltous acids ..................... 3. 5 per cent

(Test 38^) Asphaltous anhydrides .................... 2.0 per cent

(Test 38^) Asphaltenes .............................. 35-3 per cent

(Test 38^) Asphaltic resins .......................... 14.4 per cent

(Test 38*) Oily constituents ......................... 39.6 per cent

La Brea Deposit. This also occurs as an overflow in the form
of a lake at La Brea, in the Pedernales oil field, on the northwest
coast of the Island of Capure, in the delta of the Orinoco River,
some distance east of the Bermudez Lake. It is about 3200 ft.
long and 100 to 200 yards wide, and is fed by several springs and
one asphalt cone. Similar deposits on a smaller scale are found on
the neighboring islands of Paquero and Del Plata, likewise in the
District of Sucre, where cones of asphalt occur 5 ft high and 30
ft. wide.

State of Zulia.

Maracaibo Deposit. A number of asphalt deposits occur in the
Inciarte region, in the District of Mara, south of the Limon River,
60 miles west of the city of Maracaibo. Others occur at La Paz,
a short distance to the east These are in the form of overflows,
exuding from springs. More than 100,000 tons were collected

150 NATIVE ASPHALTS OCCURRING IN FAIRLY PURE STATE VIII

during 19011905, but operations have since largely ceased. The
asphalt was gathered by means of picks and shovels and trans-
ported in barges down the Limon River to the island Toas at the
head of the Gulf of Maracaibo, where it was loaded on board
steamers. It melts at a higher temperature than the Bermudez
asphalt, and possesses a very strong and characteristic sulfurous
odor.

According to Clifford Richardson 12 it tests as follows :

(Test 4) Fracture Conchoidal

(Test 5) Lustre Very bright

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i .06-1 .08

(Test 90 ) Hardness, Moh's scale Less than i

(Test 9^) Penetration at 77 F. ... v 20-30

(Test 16) Volatile at 325 F., 5 hrs i . 5-6 per cent

Volatile at 500 F., 5 hrs 4.7-6.0 per cent

(Test 19) Fixed carbon 15.0-19.0 per cent

(Test 21) Solubility in carbon disulfide 9 2 ~97 per cent

Non-mineral matter insoluble 1.4-5.0 per cent

Free mineral matter i . 5-6 . o per cent

(Test 22) Carbenes 1.5 per cent

(Test 23) Solubility in 88 petroleum naphtha 45~55 per cent

(Test 34) Saturated hydrocarbons 25-30 per cent

EUROPE

FRANCE

Department of Puy-de-D6me (Auvergne). In the vicinity of
Clermont-Ferrand, seepages of soft asphalt exude from crevices
in the rock, containing 90 per cent of asphalt, 7 per cent water, and
3 per cent mineral substances. The exudations are comparatively
small in amount, and the asphalt has never proved of importance
commercially.

At Pont-du-Chateau there occur extensive deposits of rock as-
phalt, from which soft asphalt seeps in moderately large quantities
and is caught in subsidiary workings excavated for this purpose.
Prior to 1914, approximately 100 tons of pure liquid asphalt were
recovered annually in this manner. This represents practically the
only locality in Europe where an appreciable quantity of pure as-
phalt is obtained at the mines.

VIII EUROPE 151

ALBANIA

Selenitza (Sclinitza). At the junction of the Vojutza (Vo-
jusa) and Sauchista Rivers, extending from the towns of Kanina
to Berat, in the vicinity of the Bay of Avlona (Valona), there
occurs a fairly large deposit of moderately hard asphalt in sand-
stone and conglomerate, in veins s wide as 10 ft. Marine fos-
sils are associated with this deposit, indicating it to be of animal
origin. The asphalt breaks with a conchoidal fracture, showing a
high lustre. It contains between 8 and 14 per cent of mineral mat-
ter, averaging about 10 per cent. Comparatively large quantities
have been mined during many centuries.

GREECE

Zante. An extensive deposit of asphalt occurs in the southern
portion of the Island of Zante, in the form of springs and seepages.
The asphalt is very soft in consistency, having a specific gravity of
i.oo to i. 02 at 77 F., and carrying but a trace of mineral matter,
with a fairly large proportion of water in emulsion. The springs
occur in a region of clay and limestone, more or less saturated with
petroleum. These deposits have been worked for many generations.
The asphalt is refined in a crude way by the natives who use it for
calking the seams of ships, and as a mortar for cementing together
the stones of buildings, following the same method as practiced
centuries ago.

RUSSIA 1S

Kutais Province (Transcaucasia). In the neighborhood of
Osurgeti, about 3 km. north of the railroad station Notanebi and
about 400 m. from the railway (near the villages Yakobi and Na-
rudcha), there occurs a vein of fairly pure asphalt containing 9.66
per cent ash. Similarly, at Sakuprisgale brook, near the village of
Sameho, about 4 km. from the railroad station Notanebi, there is
found a deposit of pure hard asphalt containing 4.98 per cent ash.

Tiflis Province (Transcaucasia). In the vicinity of Tiflis, on
the right bank of the Yora River, southwest of the Cloister of Holy
David of Garedchi, there occurs a deposit of hard asphalt contain-
ing 3.86 per cent ash.

152 NATIVE ASPHALTS OCCURRING IN FAIRLY PURE STATE VIII

Uralsk Province (Russia in Asia). In the so-called Kirgisen
Steppes, near where the rivers Emba and Sagis empty into the Cas-
pian Sea, there occur asphalt deposits at Imankara and Karamurat;
also about 4 km. east of Alascha-Kasgen there are found two de-
posits of pure asphalt, one covering 4300 sq. m. and the other
1600 sq. m., ranging from a hard to a softer material of elastic
consistency.

ASIA

SYRIA (LEVANT STATES)

Villayet of Beirut. 14 At Jebel Keferie (Kfarieh), a hill near the
bend of the Nahr el Kebir, about 40 km. from the sea, on the road
between Latakia and Aleppo, there occurs a large deposit of asphalt,
covering an area 1400 by 1500 m., part of which runs quite free
from mineral contamination (contains as low as y 2 per cent ash).
It has not been worked to any extent, on account of the difficulty in
transportation to the coast

MESOPOTAMIA (IRAQ)

Deposits of pure asphalt have been reported at the following
places :

Hit. Containing 64 per cent asphalt and 36 per cent water.
The extracted asphalt contained 0.5 per cent ash and 8.3 sulfur,
fusing-point (R. and B.) 47.5 C., penetration at 77 F. 108.

Ain el Maraj (near Kerkuk). Containing 79 per cent asphalt
and 21 per cent water. The extracted asphalt contained 3.8 per
cent ash and 8.8 per cent sulfur, fusing-point (R. and B.) 64 C.,
penetration at 77 F. 25.

Ain Ma 9 Moura (Ain Mamurah). Containing 72 per cent as-
phalt and 28 per cent water. The extracted asphalt contained 0.7
per cent ash and 8.5 per cent sulfur, fusing-point (R. and B.)
52.5 C., penetration at 77 F. 73.

Quijarah, Ramadi and Abu Gir. Minor asphalt seepages have
been noted.

ASIATIC RUSSIA
Sakhalin.

Province of Nutowo. An asphalt lake, known as the "Great
Okha Asphalt Lake," occurs in Okha, on the east coast of the Island
of Sakhalin in a swampy valley, associated with a very thick variety

VIII ASIA 153

of petroleum, exuding in the neighborhood. Where the asphalt
emanates from the springs, it is very soft and sticky, but towards
the edges of the lake it is hard and brittle. The asphalt has a
rather strong odor, and contains a substantial quantity of volatile
matter. As mined, it contains: asphalt 89.7 per cent, ash 1.18 per
cent and water 9.03 per cent, and has a fusing-point of 73 C. (K.
and S.) and a penetration at 77 F. of 17. This asphalt occupies
an intermediate position between Trinidad and Bermudez Lake as-
phalts. 15 After being air-dried, it carries 0.75 per cent of mois-
ture, 0.22 per cent of ash, and the balance pure asphalt containing
0.80 to 0.85 per cent sulfur. It is estimated that at least 400,000
tons of asphalt, averaging 0.9 per cent of mineral matter, are pres-
ent in the lake. Up to the present, the deposit has not been devel-
oped commercially. 16

PHILIPPINE ISLANDS
Island of Leyte.

Several asphalt deposits have been found in this region, one
near the head of the Butason River, about 6 miles from the Barrio
of Campocpoc, on the northwestern coast of the island, and another
near the town of Villaba. 17 These occur in limestone and sand-
stone, and extend over an area 12 miles long. Outcrops of various
grades of asphalt have been reported, including the solid, viscous
and liquid types. Both pure and rock asphalts are found, the latter
carrying a variable proportion of sand. Two varieties of pure,
hard asphalt were examined by the author, one having a black color
in mass, and a glossy, black, conchoidal fracture : another having a
dark brown color in mass, w T ith a hackly, dull fracture. They tested
as follows:

Black Asphalt Brown Asphalt

(Test 4) Fracture Conchoidal Hackly

(Test 5) Lustre Bright Dull

(Test 6) Streak on porcelain Black Yellowish brown

(Test 7) Specific gravity at 77 F 0.978

(Test 9^) Penetration at 77 F 10 2

(Test gc) Consistency at 77 F 31.7 Above i oo

(Test 100) Ductility at 77 F # o

(Test 15*) Fusing-point (K. and S. method) 287 F. 138 F.

(Test 1 6) Volatile at 500 F., 5 hrs 3 per cent 1 . 15 per cent

(Test 19) Fixed carbon 10. 5 per cent 9.4 per cent

(Test 21) Soluble in carbon disulfide 98 per cent 99 per cent

Mineral matter 2 per cent i per cent

(Test 37*) Saponifiable matter o per cent o per cent

154 NATIVE ASPHALTS OCCURRING IN FAIRLY PURE STATE VIII

The brown variety is unique. It is somewhat similar in physical
properties to ozokerite, but it is very much more friable. When
melted it turns black in mass, becoming lustrous (although it still
shows a yellowish brown streak). It has been marketed under the
name "leyteite." The black asphalt is not classed as an asphaltite
in view of its comparative softness at 77 F. These deposits have
not yet been exploited commercially.

CHAPTER IX

NATIVE ASPHALTS ASSOCIATED WITH MINERAL

MATTER

This chapter will include the principal deposits of natural as-
phalts containing 10 per cent and over of associated mineral matter,
based on the dry weight. Such deposits include veins, strata and
lake formations.

NORTH AMERICA

UNITED STATES 1
Kentucky.

All the deposits in the State of Kentucky are composed of sand
and sandstone, carrying between 4 and 12 per cent of soft asphalt
filling the interstices. 2 These deposits occur in strata from 5 to 40
ft. thick, along the eastern and southeastern border of the coal field
in Hardin, Grayson, Breckinridge, Edmonson, Hart, Warren, But-
ler, Logan, and other adjoining counties.

Hardin County. A deposit of sand asphalt occurs a few miles
northeast of Summit, in the southwestern portion of Hardin County.

Carter County. This deposit occurs one-half mile southeast of
the town of Soldier, and consists of unconsolidated quartz grains
held together by 4 to 10 per cent of asphalt, which is compara-
tively soft and contains a goodly proportion of volatile matter.

Breckinridge County. This deposit is located from 2 to 4 miles
south of Garfield, and is composed of unconsolidated quartz grains
carrying 4 to 8 per cent of asphalt It forms a hillside ledge about
14 ft. thick with an overburden of 10 to 20 ft. The deposit has
not been worked to any great extent in recent years, although for-
merly it was of considerable interest in the paving industry. Other
prospects occur in this neighborhood, but these have not been de-
veloped*

Grayson County. Two deposits have been worked in this lo-
cality in the vicinity of Big Clifty and Grayson Springs Station, one

155

156 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

3 miles southwest, and the other 9 miles north of Leitchfield. The
former occurs in a stratum 5 ft. thick, impregnated with 6 per cent
of asphalt, in an unconsolidated quartz sand. The second was for-
merly one of the most active mines in Kentucky, but has now been
idle for a number of years. It consists of a stratum 10 ft. thick,
carrying 7-12 per cent of very soft asphalt. A number of seepages
are in evidence along the side walls of the quarry and since the
asphalt contains a large proportion of volatile matter, they soon
harden on exposure to the weather. Some of the seepages exam-
ined by Richardson contained 30 to 65 per cent of mineral matter,
the extracted asphalt showing a penetration of between 35 and 45
at 77 F., and yielded 12 per cent of fixed carbon. Another deposit
occurs at Tar Hill.

Edmonson County. Deposits of asphaltic sandstone, estimated
to exceed 200 million tons, covering over 7000 acres, are located
about 6 miles due west of Brownsville and about 12 miles northeast
of Bowling Green. The properties adjoin both Bear Creek and
Green River, being located on both sides of the former and north
of the latter. Soil overburden of 5 to 40 ft. covers a horizontal
stratum of rock asphalt 15 to 30 ft. thick. The latter analyzes as
follows :

(Test 21) Soluble in carbon disulfide 4.22- 9.00 per cent

Matter insoluble 95.64- 90.91 per cent

(Test 25) Moisture at 105 C o. 14- 0.09 per cent

100.00 100.00 per cent

At the present time the only deposits in the State of Kentucky
worked to any extent occur at Kyrock and at the town of Asphalt,
on the Nolin River, about 10 miles west of the celebrated Mam-
moth Cave, near Brownsville. They consist of a stratum of fine sand
impregnated with 8 to 10 per cent of asphalt, occurring in irregular
beds 5 to 36 ft. thick in a horizontal stratum below an overburden
of clay and unimpregnated sandstone, 6. to 30 ft. thick. The over-
burden is removed by a hydraulic pressure line, and where it does
not yield to this, a steam shovel is used. The rock asphalt is re-
moved by quarrying as illustrated in Figs. 45 and 46, and conveyed
by a gravity tramway to a crusher which reduces the rock from 5- to
loin, fragments to lumps about the size of an egg. It is then

NORTH AMERICA

157

Courtesy Kentucky Rock Asphalt Co.
FIG. 45. Asphalt Deposit at Kyrock, Kentucky.

Courtesy Kentucky Rock Asphalt Co.
FIG. 46. Hillside Quarry of Kyrock Asphalt Deposit

158 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

passed through a battery of pulverizers, illustrated in Fig. 47, which
further reduces the rock asphalt to small grains about the size of
corn meal. A bucket conveyor transports the asphalt to barges on
the Nolin River, which in turn are conveyed down to the Green
River, and up Barren River to the railroad at Bowling Green. It
is used exclusively for paving purposes, and is reported to give ex-
cellent results.

In preparing the paving mixture, rocks of varying asphalt con-
tent are blended to obtain a product carrying uniformly 7 per cent
( y per cent) asphalt soluble in carbon disulfide. In applying

Courtesy Kentucky Rock Asphalt Co.
FIG. 47. Pulverizing Kentucky Rock Asphalt at Kyrock, Kentucky.

the asphalt, it is spread loosely over the primed base in a layer
about 3 in. thick over macadam (9 to 10 in. thick), or a concrete
base (6 in. thick), and compacted cold with a 1 5-ton steam roller,
to a thickness of 2 in., provided, however, that the air temperature
is not lower than 60 F. If necessary, the surface may be planed
after the first rolling, by which the excess material is shaved from
the high places and deposited in the depressions. The product has
the advantages of not requiring a hot mixing plant. It presents
a rather gritty surface, which prevents slipping, does not become
svavy under traffic, and may be readily repaired. To offset these,
it has the disadvantage of being marked by traffic for several days
after being laid, and moreover it is claimed that the drip from

IX NORTH AMERICA 159

autos readily washes out the asphalt content, leaving unconsoli-
dated sand.

Warren County. Several deposits of sand asphalt are located
at Youngs Ferry on the Green River, 12 miles north of the town of
Bowling Green. One occurs in a bed about 10 ft. thick, and car-
ries between 6 and 9 per cent of asphalt A second consists of a
vein 5 to 15 ft. thick containing about the same percentage of as-
phalt. Both are undeveloped. The extracted asphalt shows a
penetration at 77 F. of 200, and much volatile matter (13 per
cent at 400 F. in seven hours).

Logan County. A quarry has been opened up about 5 miles
northeast of Russellville, exposing about 15 ft. of asphaltic sand-
stone in a bed about 100 ft. long. The rock carries about 7 per
cent of asphalt, which shows very much less volatile matter than
the preceding (about 4 per cent loss at 325 F. in five hours). This
mine is no longer active.

Missouri. 3

Lafayette County. A bed of asphaltic sand occurs I J^ miles
northwest of Higginsville, carrying 8^ per cent of asphalt, asso-
ciated with sandy shale. This deposit has not been worked com-
mercially.

Indiana.

While drilling for oil at Princeton, a bed of asphalt several feet
thick was found 100 ft. below a vein of coal. Seepages of liquid
asphalt have also been reported in a well in the neighborhood.
None of these have been developed.*

Oklahoma.

This state is one of the richest asphalt-bearing centers in the
United States. Asphalts are found in both the liquid and solid
forms, occurring as springs, seepages and rock impregnations. Prac-
tically all the deposits are found in the southern portion of the state,
between the 35th parallel of north latitude, and the Red River on
the south, and included between the Arkansas line on the east, to the
city of Granite, Oklahoma, on the west. This area is shown in
Fig. 48, and includes deposits or prospects in the following counties :
Comanche, Jefferson, Stephens, Garvin, Carter, Murray, Love,
Marshall, Johnston, Pontotoc, Atoka, McCurtain and Leflore.

160

ASPHALTS ASSOCIATED WITH MINERAL MATTER

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NORTH AMERICA

161

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162

ASPHALTS ASSOCIATED WITH MINERAL MATTER

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NORTH AMERICA

163

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164

ASPHALTS ASSOCIATED WITH MINERAL MATTER

The deposits consist of asphaltic sands, asphaltic limestone, mix-
tures of the two, and rarely asphalt impregnated shale. The prin-
cipal occurrences are included in Table XVL 5

In the majority of cases the asphaltic impregnation is of liquid
to semi-liquid consistency, having a comparatively low fusing-point.
It is contended by some authorities that the vast deposits of sand
asphalt previously constituted oil-sands which have been laid bare
by the agencies of erosion, faulting, crumpling and upturning of the

ASPHALT.

I* ! AgptaH Sects.

FIG. 48. Map of Asphalt Region in Oklahoma.

strata, so that the lighter oils and gases have escaped into the air,
leaving the sand impregnated with the comparatively non-volatile
asphaltic constituents. Most of the deposits occur along pronounced
fault lines, although faulting is not essential, since certain deposits
haye become impregnated by the uprising of asphalt-bearing pe-
troleum from regions below, through the porous sandstone or

limestone.

A characteristic feature of these deposits is the sand grains,
which are round and unconsolidated, being held together by the
asphalt filling the voids. When the asphalt is extracted the grains

NORTH AMERICA

165

fall apart, and show the same general characteristics as an ordinary
petroleum-bearing sand.

The extent of these deposits has been variously estimated from
2 to 13 million tons. 6

Most of the asphalt mined in Oklahoma has been used for pav-
ing purposes, and the author has seen many satisfactory pavements
laid through the state which have withstood the wear and tear
of traffic, also exposure to the elements. It is generally necessary
to modify the rock asphalts either by combining the products ob-
tained from different deposits, or by incorporating pure sand, until
a proper balance is obtained between the asphalt and the mineral
constituents. In general, the best results have been obtained with
mixtures containing 7 to 10 per cent of asphalt in the finished paving
composition.

Numerous water-extraction plants have been erected to separate
the asphalt from the sand, but most of these have proven unsuc-
cessful, since the extraction process raises the price of the refined
asphalt so that it is unable to compete with petroleum asphalts ob-
tained from other sources in the neighborhood.

Tests made with sand asphalt taken from the quarry in Carter
County, Sec. 12 and N y 2 Sec. 13, T 3 S, R 2 W, 18 miles north-
west of Ardmore, indicated the following. The dry sand asphalt
contained 12.5 per cent of pure asphalt having a fusing-point (K.
and S. method) between 65 and 69 F. On subjecting it to the
water-extraction process, the following results were recorded :

Products
Recovered,
Per Cent.

Asphalt
Content,
Per Cent.

Total Pure
Asphalt,
Per Cent.

Impure asphaltic residue

1.8

Separated sand waste

2.3

2.7

Asphalt in crude rock

12.5

Total

IOO

On boiling the crude rock with water, impure asphalt rises to the
surface, and the "sarid waste" settles to the bottom. Upon dehy-

166

ASPHALTS ASSOCIATED WITH MINERAL MATTER

drating the impure asphalt, more sand settles out, constituting what
is designated u impure asphaltic residue." The pure asphalt drawn
off from this residue is termed "asphalt recovered."

The "asphalt recovered" contained 5 per cent of mineral matter
and tested as follows:

(Test gb) Penetration at 32 F 85

Penetration at 77 F Over 360

Penetration at 115 F Too soft

(Test 9<r) Consistency at 32 F 10.0

Consistency at 77 F i . 5

Consistency at 115 F o.o

(Test gd) Susceptibility index 15

(Test 1 5*) Fusing-point (K. and S. method) 65-69 F.

(Test 15*) Fusing-point (R. and B. method) 78-87 F.

(Test 16) Volatile at 500 F. in 5 hrs 10 per cent

Examination of Residue (from Test 16)

(Test 9^) Penetration at 32 F 7

Penetration at 77 F 58

Penetration at 115 F 250

(Test 9^) Consistency at 32 F 7 2 -*>

Consistency at 77 F 10.7

Consistency at 115 F i . I

(Test gd) Susceptibility index 63. i

(Test io) Ductility at 77 F Over 100

(Testi5*) Fusing-point (K. and S. method) ii5F.

(Test i$b) Fusing-point (R. and B. method) 131 F.

Upon evaporating the "asphalt recovered" at 250-260 C, the
following figures were recorded :

Total Loss, Per Cent.

25
27

Fusing-point F.
(Test 15*)

120
125

H7
165

Penetration at 77 F.
(Test gb)

19
10

A sample of the "asphalt recovered" upon being blown with dry
air at 300 C. for nine hours, lost 23 per cent in weight, showed a
fusing-point of 165 F., and a hardness at 77 F. of 38.0 (Test 9^),
corresponding to a penetration at 77 F. of 8 (Test gb). It is ap-
parent that the extracted asphalt is scarcely affected by blowing, and
thus differs from asphalts obtained upon distilling petroleum. It

IX NORTH AMERICA 167

has been reported that blowing decreases the percentage of asphal-
tous acids, anhydrides, oily constituents and resins. The molecular
weight of the resins increases from 733 to 1012 and that of the
asphaltenes from 2219 to 4690 during the blowing process. 7 It
has been further corroborated by the author's observations on paints
made from the extracted sand asphalt, which were found to be
highly resistant to atmospheric oxidation. A sample spread on
cloth and exposed to air indoors for about a year, showed scarcely
any diminution in tackiness. 8 Petroleum asphalts of the same con-
sistency when tested in a similar manner, dry out in a much shorter
time.

A mixture containing 82' per cent of the u asphalt recovered"
fluxed with 1 8 per cent of grahamite, showing the same fusing-point
(165 F.), tested as follows:

(Test 7) Specific gravity at 77 F i .09

(Test 9^) Penetration at 1 15 F 26

Penetration at 77 F 17

Penetration at 32 F 9

(Test 9*) Consistency at 1 1 5 F 14. 7

Consistency at 77 F 27. i

Consistency at 32 F 65 . 4

(Test 9</) Susceptibility index 30.7

(Test io) Ductility at 115 F 4.5

Ductility at 77 F i.o

Ductility at 32 F o.o

(Test 11) Tensile strength at 115 F 1.8

Tensile strength at 77 F 6.5

Tensile strength at 32 F 9.5

(Test 15*) Fusing-point (K. and S. method) 165 F.

(Test 15^) Fusing-point (R. and B. method) 183 F.

(Test 16) Volatile at 500 F. in 5 hrs o. 5 per cent

Arkansas.

Seven to eight known deposits of asphalt occur in southwestern
Arkansas, in Pike and Sevier Counties, only one of which has been
developed into a mine producing commercial quantities. This is
located 2 l /2 miles south-southeast of Pike, in Pike County. The
asphalt impregnates nearly horizontal strata of unconsolidated
sand, except in one locality, where it impregnates gravel. The veins
run from i in. to 12 ft. thick.

Pike County. The most important deposit occurs on the west
side of the road connecting the towns of Pike and Delight, about
2 y 2 miles south-southeast of Pike. It has been mined in an open

168 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

cut 100 ft wide, 200 ft. long and 15 ft. deep. The sand carries
from 5 to 1 6 per cent asphalt, averaging 7^2 per cent, and is used
for paving purposes. Prospects occur about 4 miles north-north-
west of Delight in a bed 3 to 5 ft. thick, carrying up to 17 per cent
asphalt associated with sand carrying a few nodules of iron pyrites;
also about I mile northeast of Murfreesboro, on the east bank of
Prairie Creek, in which the asphalt impregnates gravel.

Sevier County. Prospects occur y* mile southeast of Lebanon,
alongside of the road adjoining the Salina River bottom, in len-
ticular formations up to i ft. thick; another about 2 l / 2 miles west-
southwest of Lebanon; another on the south side of the road 4
miles west-southwest of Lebanon; and still another 6y 2 miles west-
southwest of Lebanon along the road just northwest of Moody
Shoal Ford on Cossatot River.

Alabama.

An area occurs in northern Alabama measuring about 72 miles
by 8 miles in which i to 15 per cent of asphalt is associated with
unconsolidated sand granules. It extends through the following
counties : 10

Colbert County. A fairly extensive deposit of sand asphalt has
recently been developed near Florence, on the banks of the Ten-
nessee River, in the vicinity of Muscle Shoals, which has been used
in the vicinity for paving purposes. Another deposit occurs i mile
south of Margerum, on the Southern Railroad, w r ithin an area 3
miles square, consisting of asphaltic limestone. Others have been
reported 2 miles southeast of Cherokee, consisting of asphaltic
limestone and sand; likewise sand asphalt deposits i to 7 miles east
of Littleville, and at Leighton and Russelville (extending into
Franklin County).

Lawrence County. Asphalt sand is found at Wolf Springs on
the summit of Little Mountain, about 6 miles southwest of Town
Creek Station on the Southern Railroad. Another deposit occurs
at Caddo, midw r ay between Moulton and the Morgan County line,
in the southeast section.

Morgan County. A sand asphalt deposit occurs about 3 miles
northwest of Flint Station on the L. & N. Railroad, and another
in the vicinity of Hartsville, to the east and southeast thereof.

IX NORTH AMERICA 169

Louisiana.

Lafayette Parish. A sand asphalt deposit has recently attracted
attention about 5 miles from Lafayette, covering about 50 acres on
the surface. 11

Texas. 12

Montague County. Deposits are reported 3 to 3 J4 miles north-
east of the City of St. Jo, carrying between 5 and 1 1 per cent of
asphalt, averaging in the neighborhood of 7 per cent, although the
percentage varies in different localities. They contain sandstone,
or a mixture of sandstone and limestone, but are of no commercial
importance.

Burnet County. This occurrence is at Post Mountain near the
town of Burnet, and consists of an asphaltic limestone, containing
about 10 per cent of asphalt of a very soft consistency (having a
penetration of 20-250 at 77 R).

Uvalde County. The most important Texas deposits are found
in the southwestern part of this county near Cline, about 18 to 25
miles west of the city of Uvalde, in the region of the Anacacho
Mountains. They consist of limestone, carrying 10 to 20 per cent
of asphalt, averaging about 15 per cent Crystalline calcite is pres-
ent, also numerous fossil remains of molluscs, indicating the asphalt
to be of animal origin. The deposits have been traced for several
miles, but their exact extent is not accurately known. A large quan-
tity has been quarried, and from recent reports the mines are still
being operated. The impregnating asphalt is quite hard, showing
a conchoidal fracture and brilliant lustre. It has a moderately
high fusing-point, and analyzes: carbon 81 per cent, hydrogen 12
per cent, sulfur 6^2 per cent, nitrogen l /2 per cent; total 100 per
cent. The rock asphalt is too hard for a paving material if used
alone. It is therefore mixed with about 25 per cent of trap rock
and the requisite amount of flux. The mixture is adapted to be
rolled cold in surfacing a pavement. One ton will cover 20 sq. yd.
I in. thick. Fig. 49 illustrates the principal mine, with about 80,000
tons of asphalt rock blasted loose and ready to be loaded into the
cars by the steam shovel. It is then transported to the mixing and
crushing plant. Fig. 50^ shows the equipment for crushing and
screening the rock asphalt; Fig. $oB the device for mixing the trap

170

ASPHALTS ASSOCIATED WITH MINERAL MATTER

rock with the rock asphalt; and Fig. 5oC shows a 42 cu. ft. capacity
twin pug-mill which is used for pulverizing the asphalt. The pure
asphalt extracted from the rock has been marketed under the name
"litho-carbon" 13 which may also be blown. This constitutes the
most important deposit in Texas.

Courtesy Uvalde Asphalt Compan;.
FIG. 49. Rosk-asphalt Quarry in Uvalde County, Texas.

Litho-carbon shows the following tests :

Color in mass ..... . . . . ...... ................. Black

Fracture ................................... Conchoidal

Lustre... ...... ..... ....................... Bright

Streak ..................................... Brownish black

Specific gravity at 77 F ...................... i ^9

Penetration at 115 F ........ ................ 16

Penetration at 77 F ......................... 4

Fusing-point (K. and S. method) .............. 1 16 F.

Volatile at 500 F., in 5 hours ................. 2.76 per cent

Soluble in carbon disulfide ..................... 96 . 35 per cent

Non-mineral matter insoluble ................. 0.75 per cent

Mineral matter ........... ................... ^-9Q per cent

(Test i)

(Test 2)

(Test 3)

(Test 4)

(Test 7)

(Test 9^)

(Test 15*)
(Test 16)
(Test 21)

100 . oo per cent
(Test 23) Soluble in 88 petroleum naphtha ............. 53 .08 per cent

Other deposits of the same general character are found in the
neighborhood. One 20 miles south-southwest of Uvalde and 5

NORTH AMERICA

171

bfl

we
5!

1 a

2
75

172 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

miles south of the preceding quarry showed 12 per cent of asphalt
with 17 per cent of fixed carbon.

Kinney County. The Uvalde deposits extend westward into
Kinney County, with outcroppings near Blewett, where mining op-
erations have been undertaken.

Anderson, Jasper, and Cooke Counties. Minor deposits are
reported in these counties, but are of no commercial value. 1

Utah.

Carbon County. 19 A deposit of asphaltic limestone occurs at
the head of the right-hand branch of Pie Fork, a canyon northwest
of the town of Clear Creek. The rock is non-uniform in composi-
tion, some containing between 6 and 14 per cent of asphalt (having
a penetration at 77 F. of 7 to 15), and some as high as 75 per
cent (showing a penetration at 77 F. of 45) with scarcely any
fixed carbon. Another deposit of asphaltic sand has been reported
8 miles from Sunnyside on the tributaries of Whitmore Canyon,
in the Brook Cliffs on the West Tavaputs Plateau, carrying 1 1 per
cent of soft asphalt, which upon being extracted tested as follows:

(Test 16) Volatile at 325 F., 5 hrs 6.6 per cent

(Test 19) Fixed carbon 5.0 per cent

(Test 23) Soluble in 88 petroleum naphtha 91 . 8 per cent

Utah County. A large area underlaid with asphaltic limestone
occurs just north of Colton, and south of Strawberry Creek, extend-
ing from Antelope Creek on the east to Thistle on the west. The
principal deposit is at the town of Asphalt, carrying 12 per cent of
asphalt.

Grand County. At the head of the West Water Canyon about
20 miles north of the town of West Water, there is an asphaltic
limestone deposit containing 50 per cent asphalt and 50 per cent
limestone. Investigations indicate that this asphalt is a progenitor
of gilsonite. The extracted asphalt is reported by Clifford Rich-
ardson to test as follows :

(Test 7) Specific gravity at 77 F 1 .037

(Test oi) Penetration at 77 F 22

(Test 16) Volatile at 212 F 2.8 per cent

(Test 19) Fixed carbon ' 8 .o per cent

(Test 23) Soluble in 88 petroleum naphtha 88.7 per cent

IX NORTH AMERICA 173

Vint a County. The largest deposit of asphaltic sandstone
occurs 3 to 4 miles southwest of Vernal, north of the Green River,
between the Ashley and Uinta Valleys, in an outcrop about n l / 2
miles long, known as "Asphalt Ridge." 16 It contains 8 to 15 per
cent by weight of asphalt, averaging 11^2 per cent A typical
specimen analyzed as follows:

(Test 21) Soluble in carbon disulfide 12.8 per cent

Mineral matter on ignition 86.45 per cent

(Test 16) Volatile at 105 C. in i hour 0.20 per cent

The extracted asphalt tested as follows:

(Test 7) Specific gravity at 77 F 0.980

(Test 19) Fixed carbon 7.1 per cent

The asphalt' has been used successfully just as it is mined, for
paving the streets of Vernal.

Another deposit, or rather a series of deposits, occur in Argyle
Creek, a tributary of the Minnie Maud Creek, which in turn flows
into the Green River about 20 miles south of Ouray. The ma-
terial consists of an asphaltic sandstone, exploited under the name
"argulite," carrying between 8 and 10 per cent of asphalt. The
extracted asphalt tests as follows :

(Test 5) Lustre Bright

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F o. 997-1 .013

(Test 9^) Penetration at 77 F 14

(Test 16) Volatile at 325 F. in 5 hrs 25. 8 per cent

(Test 19) Fixed carbon 8.55

(Test 23) Soluble in 88 petroleum naphtha , 88

(Test 26) Carbon 89.9 per cent

(Test 27) Hydrogen 9.0 per cent

(Test 28) Sulfur o.o per cent

(Tests 29 and 30) Nitrogen and oxygen i . i per cent

Total 100.0 per cent

(Test 340) Saturated hydrocarbons 25 per cent

Wyoming.

Fremont County. Asphalt and semi-solid asphalt seepages
were used for many years as fuel by shepherds on Copper Moun-
tain in section T. 4 N., R. 9293 W., in northeastern Fremont
County.

174

ASPHALTS ASSOCIATED WITH MINERAL MATTER

California, 17

Mendocino County. Deposits of asphaltic sand are found 2
miles north of the town of Point Arena and l / 2 mile from the coast,
carrying between 6 and 7 per cent of asphalt. A similar deposit
occurs just north of Port Gulch.

Santa Cruz County. Large deposits of asphalt sand occur 4 to

FIG. 51. Sand Asphalt Quarries in Santa <Jruz county, v;ai.

6 miles northwest of the city of Santa Cruz, near the summit of
Empire Ridge, a spur of the Santa Cruz Mountains, 3^ miles
from the coast. A number of quarries have been opened up in this
region, and the product used for constructing pavements in Santa
Cruz and San Francisco. The rock contains between 10 and 17^
per cent asphalt of variable hardness, containing a substantial pro-
portion of volatile matter. The veins vary from 2 to 32 ft thick,

NORTH AMERICA

175

as shown in Figs. 51 and 52. Three strata are found, an upper
8 ft thick containing 2-3 per cent asphalt, a middle one 32 ft.
thick containing 14 per cent asphalt, and a lower 25 ft. thick carry-
ing 1 6-1 8 per cent asphalt.

Monterey County. Several deposits of asphaltic sandstone are
scattered throughout the Salinas Valley. A prospect occurs about
10 miles from King City, composed of particles of quartz, feldspar
and mica, impregnated with a varying percentage of asphalt. An-
other deposit occurs 7 miles southeast of Metz at the head of

A-UJ. 5*. oanu -mspnair uuarnes in Santa Cruz County, Cal.

Chelone Creek, of the same general character. A large vein, about
125 ft. thick and 3 miles long, has been reported near San Ardo,
composed of coarse quartz grains, and a little feldspar, impregnated
with a small percentage of asphalt.

San Luis Obispo County. Sand asphalt deposits occur about
80 miles southwest of the town of San Luis Obispo, consisting of
a number of actively worked quarries. The rock is fine grained, of
even texture, consisting mostly of quartz, with a small quantity of
feldspar. The percentage of asphalt varies from 8 to 18 per cent,
averaging about 10.

176 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

Santa Barbara County. Santa Maria Region. Associated
with the pure asphalt deposits already described* zones of asphalt-
impregnated shale have been reported on the western slope of the
Azufre Hills, containing 30 to 40 per cent of asphalt.

Sisquoc Region. Deposits of sand asphalt occur in the neigh-
borhood of the town of Sisquoc, carrying between 14, and 18 per
cent of asphalt. The largest vein occurs in Bishop's Gulch, about
100 ft. thick, running fairly uniform in composition. 'Some time
ago an attempt was made to remove the asphalt by extraction with
solvents, but the process proved too costly and had to be abandoned.
Similar deposits are found in the neighborhood of La Brea Creek,
where a vein of sand asphalt occurs 20 to 60 ft. thick; also at Los
Alamos Creek.

Gaviota Region. A prospect has been reported in this locality
consisting of a bed of sandstone and conglomerate about 25 ft.
thick, containing 7 to 8 per cent of asphalt.

Mores' Landing, This deposit is found on the seacoast about* 7
miles west of Santa Barbara, occurring as veins and irr$gul|| masses
in massive sandstone cliffs, at least too ft. thick. Acceding to
Eldridge it contains 30 to 60 per cent of asphalt and has a strong
resemblance in structure, brilliancy, and fracture to gilsonite, al-
though it is very much softer in consistency.

La Patera Region. A vein of asphalt of historical interest only,
occurs about 10 miles west of Santa Barbara, close to the coast. It
varies in width from 2 to 12 ft, with a number of lateral branches
several inches thick. The asphalt is associated with 30 to 50 per
cent of mineral matters composed of shale, sand, and clay. It is
stated that 30,000 tons have been removed from this mine, testing,
when dried, as follows : 18

(Test 4) Fracture Irregular

(Test 5) Lustre Dull

(Test 6) Streak *.-. Black

(Test 7) Specific gravity at 77 F i .38

(Test 94) Hardness on'Moh's scale 1

(Test 9$) Penetration at 77 F o

(Test 16) Volatile at 400 F., 5 hrs 2, 5 per cent

(Test 19) Fixed carbon 14,9 per cent

(Test a i) Soluble in carbon disulfide Approx. 50 per cent

Mineral matter. . ,. i v Ab ut 5 per cent .,

(Test 13) Soluble in 88 petroleum naphtha 21 , 6 per cent

(T*stl8) Sulfur ^ ,-, 6,2 per cent >\

(Test 34*) Saturated hydrocarbons 8. i ; per cent r

NORTH AMERICA

177

Carpinteria Region. This deposit, composed of asphaltic sand
about 15 ft. thick, lying along the ocean's shore at Benham, 2 miles
southeast of Carpinteria, is illustrated in Fig. 53. It contains 18 to
20 per cent of asphalt filling the interstices of unconsolidated quartz
grains. Some time ago a process was installed for extracting the
asphalt with water, but this never proved successful commercially.

FIG, 53. Asphaltic Sand on the Shore at Carpinteria, Cal.

Orange County* Bituminous sands have been reported 4 miles
southwest of Chino, in a layer about 6 ft. thick, containing varying
percentages of asphalt.

CANADA
Alberta Province.

McMurray Region. Vast deposits of asphaltic sands occur on
both banks of the Athabaska River, and its tributary, the Clear
Water River, covering probably not less than 750 square miles. 19
The deposit varies in thickness to a maximum of 225 ft. Character-
istic views of the outcrop on the Athabaska River are shown in
54 (A and B). The material contains 12 to 20 per cent as-

178 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

phalt, averaging between 15 and 18 per cent, associated with an
unconsolidated sand consisting of betw r een 93 and 99 per cent pure

(B)

Courtesy S. C. Ells.

FIG. 54. Asphaltic Sand on Banks of Athabaska River, Alberta, Can.

silica. A marked variation in the size of the sand grains is charac-
teristic of almost every exposed section of the deposit, ranging from
40 to 80 mesh. The asphalt is amenable to the water extraction

IX NORTH AMERICA 179

process. A specimen of the extracted asphalt examined by the
author tested as follows:

(Test 7) Specific gravity at 77 F 1.022

(Test 9^) Penetration at 77 F Too soft for test

Penetration at 32 F 120

(Test 9^) Consistometer hardness at 1 15 F o.o

Consistometer hardness at 77 F o.o

Consistometer hardness at 32 F 2.7

(Test io*) Ductility at 115 F 2.0

Ductility at 77 F 7?o

Ductility at 32 F 12.5

(Test 154) Fusing-point (K. and S. method) 50 F.

(Test 15^) Fusing-point (R. and B. method) 63 F.

(Test 16) Volatile at 500 F. in 5 hrs 17.9 per cent

Volatile at 325 F. in 5 hrs * 1 1 . 2 per cent

(Test 19) Fixed carbon 7,23-10. 55 per cent

(Test 21) Soluble in carbon disulfide. 97.3 per cent

Mineral matter 2.7 per cent

(Test 23) Soluble in 88 petroleum naphtha 78 . 2 per cent

(Test 26) Carbon 84.49 per cent

(Test 27) Hydrogen 1 1 . 23 per cent

(Test 28) Sulfur 2 . 73 per cent

(Test 29) Nitrogen 0.04 per cent

Total 98 .49 per cent

(Test 340) Saturated hydrocarbons 39.6 per cent

The, non-volatile matter tested as follows :

Residue at
500 F. 325 F.

(Test 7) Specific gravity at 77 F 1.028 1.021

(Test gb) Penetration at 115 F no

Penetration at 77 F 62 262

Penetration at 32 F 18

(Test 9^) Consistency at 115 F 3.7

Consistency at 77 F 8.5

Consistency at 32 F 49 . 3

(Test gd) Susceptibility index 36. 5

(Test lot) Ductility at 115 F 34. 5 +100

Ductility at 77 F 45.0 +100

Ductility at 32 F 0.5

(Test 1 1) Tensile strength at 115 F 0.3

Tensile strength at 77 F 1.5

Tensile strength at 32 F 25. 5

(Test 150) Fusing-point (K. and S. method). 125 F. 106 F.

(Test 15*) Fusing-point (R. and B. method) 142 F. 121 F.

(Test 19) Fixed carbon 12.33 P 61 " cent 8.99 per cent

A sample of extracted Alberta asphalt having a K. and S.
fusing-point of 84 F. was blown 2 l / 2 hours at 500 F. during which

ISO ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

process it lost 17 per cent in weight, and the resultant product tested
as follows:

(Test 5) Lustre. Bright'and tough

(Test g&) Penetration at 115 F 5.6

Penetration at 77 F 3.0

Penetration at 32 F i .o

(Test 150) Fusing-^point (K. and S. method) 208 F.

A duplicate sa'mple was evaporated in air until it lost exactly
1 7 per cent by weight, whereupon the residue showed a f using-point
of 128 F. (K. and S.), demonstrating that the material was sus-
ceptible to the process of blowing.

The crude asphalt, after being tempered with additional pure
sand to reduce the percentage of asphalt, has given successful results
for paving purposes in Edmonton, Canada. (

Manitoba Province. Similar deposits are reported to occur in
the Clear River District in this province. 20

MEXICO

States of Vera Cruz and Tamaulipas. Several deposits of
sand asphalt have been reported in the neighborhood of Tampico
and Vera Cruz, containing 8 to 14 per cent of asphalt, but none
have been developed commercially.

CUBA 2 *

Province of Matanzas. Semi-solid asphalts have been mined for
many years at the bottom of Cardenas Harbor, 22 The most im-
portant deposit, known as the u Constancia Mine," occurs about 12
ft. below the level of the water, and is consequently mined with
difficulty. Other deposits of semi-liquid asphalt containing more or
less mineral matter, occur at the mouth of the La Palma River,
about 20 miles from Cardenas; also near Sabanilla de la Palma,
about 30 miles east of Cardenas and 4 to 5 miles west of Hato
Nuevo. Analyses are not available.

Province of Pinar del Rio. Deposits of sand asphalt have been
reported at Bahia Honda and Mariel, in the neighborhood of
Mariel Bay> also at Vuelta Abajo. No analyses are available.

Province of Havana. An extensive deposit approaching glance

IX NORTH AMERICA 181

pitch in properties, known as the u Angelo Elmira Mine/' has been
found near Bejucal, about 18 miles south of Havana, associated
with mineral matter composed of calcium carbonate, silica, and sili-
cates, which, according to Clifford Richardson, 28 tests as follows :

(Test i) Color in mass Brownish black to black

(Test 4) Fracture SemUconchojdal to conchoidal

(Test 5) Lustre Dull

(Test 6) Streak Reddish brown to brown

(Test 7) Specific gravity at 77 F i . 30-1 . 35

(Test 9*) Hardness, Moh's scale 2-3

(Test 9*) Hardness, penetrometer at 77 F. . . o
(Test 16) Volatile at 325 F., 5 hrs, (dry sub-
stance) About i per cent

Volatile at 400 F., 5 hrs. (dry sub-
stance) About i# per cent

(Test 19) Fixed carbon 17.4-25.0 per cent

(Test 21) Soluble in carbon disulfide 70-75 percent

Non-mineral matter insoluble 3#- 4 per cent

Mineral matter (calcium carbonate,

etc.) 21-18 per cent

(Test 23) Soluble in 88 petroleum naphtha, . 32-50 per cent
(Test 28) Sulfur About 8.3 per cent

Five miles east of Bejucal, there is another deposit, similar to
the preceding.

Province of Camaguey, Impure soft and hard asphalt deposits
are found near Minas, a small town about 30 miles from Nuevitas,
and 20 miles from Puerto Principe.

Province of Santiago de Cuba. A deposit of hard impure
asphalt occurs 5 to 10 miles south of Puerto Padre in Victoria de
las Tunas district, testing as follows :

(Test i) Color in mass Black

(Test 4) Fracture Hackly

(Test 5) Lustre Dull

(Test 6) Streak Dark brown

(Test 7) Specific gravity at 77 F 1 . 106

(Test 94) Hardness, Moh's scale I .

(Test 19) Fixed carbon 9.9 per cent

(Test 21) Soluble in carbon disulfide 78.4 per cent

Non-mineral matter insoluble 18.2 percent

Mineral matter , 3,4 per cent

Total 100,0 per cent

(Test 23) Soluble in 88 petroleum naphtha ,,..,,.,.,. 60, 6 per cent

182

ASPHALTS ASSOCIATED WITH MINERAL MATTER

SOUTH AMERICA
TRINIDAD

St. Patrick County. One of the largest deposits of asphalt in
the entire world occurs on the Island of Trinidad 24 on the north
coast of South America, situated a short distance from the main-
land of Venezuela, between the Caribbean Sea on the west and the
Atlantic Ocean on the east.

Small deposits are scattered all over the Island, but the largest
one known 'as the "Trinidad Asphalt Lake/' is situated on La Brea
Point, in the Wards of La Brea and Guapo, on the western shore.
The lake is situated on the highest part of La Brea Point, 138 ft.
above sea level. It covers an area nearly circular comprising 115
acres, in a slight depression or shallow crater at the crest of the
hill. The exact location of the lake is shown in Fig. 55. The lake

measures about 2000 ft. across
and is over 135 ft. deep in the
center, becoming shallower to-
wards the edges. A panoramic
view is shown in Fig. 56.

The asphalt surface is broken
up into a series of large folds with
accumulations of rain water in the
creases. A typical view is shown
in Fig. 57. The entire mass of
asphalt is in constant but slow mo-
tion from the center towards the
edges, probably due to the con-
tinual influx of solid material at
the center, accompanied by a
strong evolution of gas which im-
parts a porous or honeycombed
structure. The evolution of gas
through the water is shown in Fig, 58. Wherever a hole is dug in
the surface, it slowly fills up and disappears. The asphalt is softest
in the center of the deposit, and gradually hardens towards the
circumference. Even in the center, the consistency is such that it

\3*fo ^

\{ Vyo

V V .._. Mi>*tff n jffl

NwaWt. t
foileaad track

FIG* 55. Map of Trinidad .Asphalt Lake.

SOUTH AMERICA

183

12
*3

[

184

ASPHALTS ASSOCIATED WITH MINERAL MATTER

Courtesy of Barber Co,
FIG. 57. Folds in the Surface of Trinidad Lake.

Courtesy of Barber Co.
FIG. 58. Evolution of Gas from Trinidad Lake.

SOUTH AMERICA

185

will bear the weight of a man, and can be readily broken out in
large masses with picks as shown in Fig. 59.

Shrubs and small trees grow on the surface in isolated patches
known as "islands," which slowly migrate from place to place with

Courtesy of Barber Co.

FIG. 59. Gathering Trinidad Lake Asphalt.

Courtesy of Barber Co.
FIG, 60. Transporting Trinidad Lake Asphalt.

the movement of the asphalt. Grassy vegetation extends along the
edges of the lake merging into the surrounding country.

The crude asphalt is loaded on small cars run by cable over the
lake in a loop, the rails being supported by wooden ties which must
be replaced from time to time as they gradually sink into the surface
of the asphalt. The asphalt is transferred to an inclined cable way

J86 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

at the end of the loop which runs to the shore, and thence to a long
pier where it is dumped on board steamers (Fig. 60).

It has been estimated that the lake still contains 10 to 15 million
tons of asphalt. Although vast quantities have been removed in
the past, the level of the lake has not sunk more than 8 to 10 ft,
since the rate of influx closely approximates the quantity removed.
In the past ten years approximately 10 million tons of asphalt have
been removed, during which period the level has sunk approximately
i l /2 meters.

The fresh material consists of an emulsion of asphalt, gas, water,
sand and clay. According to Clifford Richardson 25 oil sands occur-
ring at a depth carry an asphaltic petroleum and natural gas under
high pressure, which on coming in contact with a paste of colloidal
clay and silica are converted into the asphalt which emerges at the
surface.

The crude Trinidad Lake asphalt is extremely uniform in com-
position, as is evident from analyses of samples taken from different
points over the surface, calculated on a water- and gas-free basis.
The crude material, when freshly sampled at the center of the lake,
is composed of:

Water and gas volatilized at 100 C 29.0 per cent

Asphalt soluble in carbon disulfide 39.0 per cent

Asphalt adsorbed by mineral matter 0.3 per cent

Mineral matter on ignition 27 . 1 per cent

Water of hydration in mineral matter 4.3 per cent

Total 99 . 8 per cent

Specimens taken from the various portions of the lake's surface,
after pulverizing and drying to constant weight in air at room tem-
perature, appear fairly uniform in composition, averaging:

Soluble in carbon disulfide 53 .0 to 55 .o per cent

Free mineral matter 35. 5 to 37.0 per cent

Water of hydration, etc. . , * 9,7 per cent

The so-called "water of hydration, etc." includes water chemi-
cally combined with the clay, asphalt adsorbed by the clay and not
removable by carbon disulfide, and the inorganic salts which are
volatilized on ignition upon determining the mineral matter.

The mineral constituents consist of extremely finely divided
silica and colloidal clay, and have the following composition :

IX SOUTH AMERICA 187

SiOs

70.68-

66 . 9 pet cent

AlaO*

17.04-

20 . 9 per cent

7.62-

4 4 per cent

CaO

\ \

i . o per cent

MgO

2.46- 1

i . i per cent

K*OandNa 2 O

1.22-

i . 6 per cent

SOt

O.Q7

3 . 8 per cent

O.22-

o . 3 per cent

Total 100,00- 100. o per cent

The mineral matter shows the following granularmetric com-
position when separated into fractions by means of air:

* Ignited Ash Unignited Mineral
Residue

O-IOM v , . . 37 per cent 47 per cent

io-20/u 1 5 per cent 1 1 per cent

20-30^1 9 per cent 7 per cent

30-40/4 5 per cent 5 per cent

40-50;* 5 per cent 6 per cent

50-60/4 4 per cent 6 per cent

Over 60^ 25 per cent 18 per cent

Total 100 per cent 100 per cent

The mineral constituents of Trinidad asphalt may be separated
by treating with bromoform (specific gravity at 77 F. 2.59 to
2.62). The lighter constituents will float to the surface and the
heavier constituents present, including titanite, zircon, rutile and
glaucophane will settle out. The latter upon examination under the
microscope will disclose the characteristic blue color of glaucophane,
which although not very plentiful, will aid in the identification of
Trinidad asphalt, whenever present in a mixture. 26

The emulsified water contains mineral constituents in solution
to the extent of 82.1 grams (at 110 C) per kilo, composed largely
of sodium chloride. The gas is a mixture of methane, ethane, car-
bon dioxide, and nitrogen.

The crude asphalt is subjected to a refining process by heating
it to 1 60 C. to drive off the water. A small amount of volatile
matter is also removed during this treatment The refined asphalt
has been termed "parianite." * 7 A process has been suggested for
expelling the water, when the asphalt is to be used for constructing

188 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

pavements, which consists in mixing the crude asphalt with a suitable
proportion of mineral aggregate heated sufficiently high (e.g.,
400 F.) to drive off the water. 28 Another process consists in com-
minuting the crude asphalt, and drying it at a low temperature to
preserve its granular condition. 29 The refined asphalt tests as
follows :

(Test i) Color in mass Black

(Test 4) Fracture Conchoidal

(Test 5) Lustre Dull

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i .40-1 .42

(Test ga ) Hardness, Moh's scale i -2

(Test 9^) Penetration at 115 F 10 -15

Penetration at 77 F* 1.5-4.0

Penetration at 32 F 0.25-0.75

(Test gc) Consistency at 115 F 32.7

Consistency at 77 F 74. 9

Consistency at 32, F Above 100

(Test 9</) Susceptibility index Greater than 80

(Test 10*) Ductility (Dow Method):

At 115 F 8.0

At77F '. 1.8

At32F o.i

(Test io) Ductility (Author's Method):

At 115 F 1.5

At 77 F i .o

At32F o.o

(Test n) Tensile strength (Author's Method):

At 115 F 4.15

At 77 F.. 21.0

At 32 F 27.0

(Test 13) Fraas breaking-point 57 F.

(Test I 5*) Fusing-point (K. and S. method) 188 F.

(Test 1 5^) Fusing-point (R. and B. method) 206 F.

(Teat 15*) Fusing-point, pure asphalt extracted from mineral

matter (K. and S. method) 131^ F.

(Test I $) Fusing-point ditto (R. and B. method) 149 F.

(Test 16) Volatile at 335 F., in 5 hrs 1.1-1.7 per cent

Volatile at 409 F., in 5 hrs 4.0-5. 25 per cent

(Test 19) Fixed carbon 10.8-12.0 per cent

(Test 21) Soluble in carbon disulfide 56-57 per cent

Asphalt retained by mineral matter 0.3 per cent

Mineral matter on ignition with tricalcium-

phosphate. , 38 . 5 per cent

Water of hydra tion (clay and silica) 4.2 per cent

(Testaa) Carbenes 0.0-1.3 percent

(Test 23) Soluble in 88 petroleum naphtha (pure asphalt) . . 62-64 per cent

(Test 26) Carbon (ash-free basis) 80-82 per cent

(Test 27) Hydrogen (ash free basis) io-n per cent

(Test 18) Sulfur (ash-free basis), 6-8 per cent

(Test 29) Nitrogen (ash-free basis) 0.6-0, 8 per cent

(Test33) SoKd paraffins 1 Trace

SOUTH AMERICA

189

(Test 344) Saturated hydrocarbons 24.4 per cent

(Test 37*0 Saponification value , 40.0 per cent

(Test 380) Free asphaltous acids 6.4 per cent

(Test 38^) Asphaltous acid anhydrides 3 . 9 per cent

(Test 38*) Asphaltenes 33.0-37.0 per cent

(Test 38^) Asphaltic resins 23 ,0-26. o per cent

(Test 38^?) Oily constituents 31.0-32.0 percent

The following more detailed tests have been reported: 80

Test

No.

Description

Refined
Trinidad

Extracted
Asphalt

Specific gravity at 77 F * . *

1 .4.0

I O70

Float test at 212 F

14.02

A .t-/W

64?

loa

Ductility at 77 F

Fraas breaking-point ,

66 F.

<T9F.

ita

Fusing-point (K.. and S. method)

171 F.

jy * *
I4QF

Fusing-point (R. and B. method)

* / * *
203 F.

*Ty c *
l64F.

i$h

Ubbelohde drop-point

270 F.

IQOU F.

Volatile at 325 F.; 5 hours

o.o?%

0.08%

Loss (D.I.N. method)

1.10%

1.18%

lib

Flash-point (open-cup)

460^ F.

Burning-point

529 F.

Soluble in carbon disulfide

58.62%

99-8<%

Non-mineral matter insoluble

0.2O

o oo

Mineral matter (ash) ......*/

4I.I8

0. 1?

Total

IOO.OO%

IOO OO%

Sulfur

4.65%

f r %

Solid paraffins:
Alcohol-ether-fuller's earth

O,25%

0.44%

Alcohol-ether-sulfuric acid

O.40%

Alcohol-ether-D.LN. method

O,28%

-S7<2

Acid value ......

6 o

O. J.C

i8f

Asphaltenes

15 1<%

26 14%

JUl,

lid

Asphaltic resins

I7.1<%

20 . 42%

i$e

Oily constituents

1 8 . 70%

11 . QO%

Soft asphalt constituents (diff.)

7-1?%

12. C4%

Total

58.6<%

IOO.OO%

Solid paraffins in oily constituents

0.81%

1. 18%

Js>

So-called Trinidad u land asphalt^ represerits material which
overflows from the lake at its edges, where it has been exposed to
the action of the weather for centuries. It is derived from the
same source as the lake asphalt, and has the same general physical
and chemical characteristics* It is known under vairious names ; for
example: u cheese pitch 1 ' is a variety which resembles the lake as-*

190 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

phalt most closely with respect to its containing gas cavities; "iron
pitch" is a variety which has hardened on exposure to the weather
to such a degree that it resembles refined lake asphalt; "cokey
pitch" is a variety which has been coked or carbonized by brush
fires, etc.

The land asphalt varies in its composition from place to place,
but differs from the lake asphalt in the following respects :

( i^ It contains less gas and water than the lake asphalt

(2) It contains a slightly higher percentage of mineral matter
(from i to 2 per cent).

(3) More of the volatile ingredients have been evaporated.

These influence the tests as follows :

The specific gravity is somewhat higher (up to 1.45).
The hardness is greater.

The fusing-point is higher (between 30 and 40 F.).
The volatile matter is less (about i per cent).
The percentage of fixed carbon is slightly higher (about 2 per
cent).

BRAZIL

State of Parana. Asphalt occurrences are reported in many
localities in the Sierra da Baliza, in the crevices and pores of the
igneous rocks. 81

State of Sao Paulo. Asphalt is similarly reported in crevices of
a dyke at Fazenda Saltinho, in Rio Tiete, 9*^ miles above Porto
Martins. 82

ARGENTINA

Province of Jujuy. An asphalt lake, known as the "Laguna de
la Brea," occurs some distance northeast of the City of Jujuy. JThe
asphalt is sulfurous, of a semi-liquid consistency which hardens at
the edges. It is mixed with more or less earthy constituents. Seep-
ages of mineral oil are also found locally.

Province of Chubut. Deposits of soft, impure asphalt are
reported in the village of Cornodoro Rivadavia, associated with
seepages of asphaltic petroleum. The asphalt has not been devel-
oped, and no analyses are available.

Province of Mendoza. Asphalt deposits, probably resulting
from seepages of petroleum, occur in the San Rafael District at
Cerro de los Buitres, in the south of Mendoza Province. 33

IX EUROPE 191

COLOMBIA 84

Department of Bolivar. Numerous seepages of liquid to semi-
liquid asphalt, more or less associated with mineral matter, occur
along the Caribbean Sea south of Cartagena. These were origi-
nally reported by Humboldt in 1788, and have been utilized largely
for calking ships.

Department of Antioquia. Numerous occurrences of asphalt
have been reported between Nare and Puerto Berrio. 35

Department of Santander. Similar seepages of soft asphalt,
mostly associated with sand and pebbles, occur north of the Soga-
moso River which empties into the Magdalena River south of
Puerto Wilches. Such asphalts have been reported at Morokoi; at
a brook called Puente, a few kilometers north of the foregoing;
and still another farther north, at Las Monas.

Department of Boyaca. Deposits of soft asphalt associated
with sand and clay are found at Tunja and Sogamoso, north of
Bogota, in the Cord Oriental mountain range. These have been
used for paving the streets of Bogota. Similar deposits have been
reported at Macheta, Tuta, Paipa, Pesca, La Puerta, Topaga, Cor-
rales and San Francisco in the south-central part of this province.

ECUADOR

Province of Guayas. In the Santa Elena peninsula, seepages of
asphalt have been reported in pits which have been dug in pros-
pecting oil. 87

EUROPE

FRANCE 8a

Department of Landes, Near Bastenne, about 24 km. from
Orthey, a moderately large-sized deposit of asphaltic sand is found,
associated with fossil shells, indicating that this asphalt is of animal
(marine) origin. These shells are distributed throughout the as-
phalt bed, which measures between 10 and 14 ft thick. On expo-
sure to the air, the shells fall to pieces in a fine powder and the
asphalt hardens materially, due to the loss of volatile matter. An
analysis by Leon Malo shows the material to contain: asphalt 38.45
per cent, calcium carbonate 4.9 per cent, and sand 56*59 per cent.

192 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

This deposit has been worked for many years and was used for
constructing the earliest asphalt mastic pavements. 39 Similar de-
posits were formerly worked at Dax.

Department of Gard. Large deposits of rock asphalt have been
mined in the Concession of St. Jean-de-Marvejols since the first
Concession was granted by a Royal Ordinance on February 17, 1844.
Deposits also occur in the southern part of this Department, includ-
ing the Concessions of Servas, Cauvas, Les Fumades and Puech.
These have long been known (since 1844), but are no longer
worked. Lignite and coal occur in the same region. The asphalt
is associated with limestone, sandstone and shale, and varies in per-
centage between 5 and 16 per cent An average analysis shows it
to contain: asphalt 10 to 12 per cent, clay 0.5 to 0.8 per cent, cal-
cium carbonate 8486 per cent, magnesium carbonate about 2 per
cent, and moisture 0.5 per cent The penetration of the extracted
asphalt runs as follows: at 25 C. 98, at 20 C, 58, at 15 C. 32,
at 10 C. 20 and at 5 C. 10. At St. Jean-du-Gard it is necessary
to sink shafts 1000 ft. deep to reach the stratum of asphalt, which
was probably introduced into the limestone as an asphaltic petro-
leum, the lighter fractions of which evaporated, leaving the asphalt
behind/

Department of Haute-Savoie. Deposits of asphalt associated
with limestone and sandstone occur at Mussiege, Frangy, Lovagny,
Bourbonges, and Chavaroche, in strata between 13 and 16 ft thick.
An analysis of the rock asphalt mined at Chavaroche shows it to
contain: asphalt 29.2 per cent, calcium carbonate 51.6 per cent, and
sand 19,2 per cent This is used for paving purposes. The Lo-
vagny deposit contains: asphalt 4.5 per cent, volatile at 100 C. 2.3
per cent, and ash 93.3 per cent. The ash consists of CaCO 8 97.60
per cent, MgCOa 0.44 per cent, CaSO 4 0.48 per cent, Fe 5 O s 0.62
per cent, and A1 2 O 3 0.82 per cent 41

Department of Ain. The asphalt dejposits extend across the
boundary line, separating the Departments of Haute-Savoie and
Ain, ranging in a northeasterly direction, and culminating in the
ISFeuchatel (Swiss) region in the north. At Bellegarde, in the north-
eastern part of the Department, occurs a deposit of asphaltic lime-
stone, unevenly impregnated with asphalt, and associated in part
heavy petroleum oils* The well-known Seyssel deposit also

EUROPE

193

occurs in this Department, at Pyrimont 42 Minor deposits occur
also at Volant, Belley, Challenges, Forens, Obagnoux, Corbonod,
Confort, etc., consisting of a fine-grained limestone impregnated
with asphalt. This region is illustrated in Fig. 61. The deposits
consist of a series of hillside quarries on both banks of the Rhone

Bllllat

I
Q

Bcyrlat

L'hoprtal

Chancy

FIG. 61. Map of Seyssel Asphalt Deposit, France.

River. The asphalt impregnation varies from 2 to 8 per cent as a
maximum, the balance consisting almost exclusively of calcium car-
bonate. Fossil shells, also crystalline calcite, are frequently encoun*
tered. The deposits at Pyrimont have been worked for many years
by a series of underground tunnels, in eight beds, varying in thick*.

194

ASPHALTS ASSOCIATED WITH MINERAL MATTER

ness from 2 to 5 meters, on the eastern bank of the Rhone River.
Three grades of asphalt have been produced, containing 3 per cent,
5-6 per cent, and 8 per cent of asphalt respectively. The chief
merit of this product lies in the intimacy of its impregnation with
asphalt, and the fine granular structure of the associated calcium
carbonate. Prior to 1914 from 5000 to 20,000 tons were mined
annually. The following analysis represents the average composi-
tion of the Seyssel product:

Water ........................................... i-9 - - percent

Asphalt (fusing-point, 87 R, K. and S. method) ...... 8.00- 8. 15 per cent

Magnesium carbonate .............................. o. 10 per cent

Calcium carbonate .... ............................ 89 . 55~9i - 30 per cent

Iron and aluminium oxides. ......................... 0.15 P 61 " cent

Insoluble in acid .................................. o. 10- 0.45 per cent

^ etc .......................................... o. io- o. 20 per cent

The extracted asphalt shows the following penetrations (Test
gb) : at 77 F. too soft; at 60 F. 136; at 50 F. 76; at 40 F. 40.

Fig. 6 1 shows the location and extent of the Seyssel deposit.
Occurrences of asphalt have also been reported at Lelex and
Chezery, in the valley of the Valserine, north of Bellegarde.

Department of Basses-Alpes. Two deposits have been de-
scribed in the vicinity of Forcalquier, one (A) associated with lime-
stone and the other (B) with a siliceous base, testing as follows: 43

SiOa

CaCOs

Fe2O 8 andAl 2 O8

H 2 and Loss

Asphalt

* >

f\ * * .

"B"

Trace to 0.54%
58.34-59.13%

90.63-80.58%
31.34-28.40%

0.01-0.80%
0.56-0.93%

o.i3"3-52%
1.31-0.27%

9.33-14.50%
8.45-11.27%

Department of Puy-de-D6me (Auvergne). Rock asphalt de^
posits occur in numerous localities. The only present source of
production is at Pont-du-Chateau (also at Chamalieres, near Cler*
mont-Ferr and),. where 12,000 to 20,000 tons of rock asphalt com-
posed of n.o per cent asphalt associated with SiO 2 (suitable for
an acid-resisting mastic) are produced annually. Limited opera-
tions have been carried on at various times in the past at Lussat,
Malintrat, Gites-des-Roys, Puy-de-Croville, du Cortal, Pontgibaud
(west of the Chain of Puys), Plain of Limagne, and other minor
localities."

EUROPE

195

Department of Haute Vienne. Minor occurrences have been
reported at Limoges, in quartz veins traversing gneiss.

SWITZERLAND

Extensive deposits of asphalt-impregnated limestone occur west
of Neuchatel Lake, in the so-called Val de Travers region. These
have been exploited for many years and marketed under the names

FIG. 6a. Neuchatel and Val de Travers Asphalt Deposits.

"Neuchatel Asphalt" and "Val de Travers Asphalt." 45 The exact
location of the region is shown in Fig. 62, The percentage of as-
phalt varies considerably; thus, the "ordinary" grade contains 8~~io
per cent of asphalt, the so-called "rich" grade contains 10-12 per
cent of asphalt.

The average product contains: asphalt 10.15 per cent (fusing-
point 50 F., K. and S. method), calcium carbonate 88.4 per cent,

106

ASPHALTS ASSOCIATED WITH MINERAL MATTER

calcium sulfate 0.25 per ceiit, iron and aluminium Oxides 0.25 per
cent, magnesium carbonate 0.3 per cent, matter insoluble in acid
0.45 per cent, and loss 0.5 per cent The extracted asphalt shows
the following penetrations (Test $b) : at 77 F. too soft; at 60 F.
1 12; at 50 F. 57. The fusing-point (Test 15^) is 43 C, and the
ductility at 77 F; (Test 100) over 115 cm.

The theory has been advanced that these asphalts have been
produced by the decomposition of marine animal and vegetable
matters, which is borne out by the associated fossils.

Outcrops occur at Auvernier, Bevaix, Bois-de-Croix, Presta,
Bulles, and St. Aubin, south of Neuchatel, on the western shore of
Lake Neuchatel, carrying smaller percentages of asphalt than the
preceding.

ALSACE-LORRAINE

The deposits in this region occur in a well-defined area in the
neighborhood of Lobsann a short distance north of Strasbourg, as
shown in Fig. 63. The asphalt strata have been traced 6 to 7 miles

Schacht Pechelbronn

* SOULTZ-SOUS-FOR
Walbourg

FIG. 63, Map of Lobsann Asphalt Region, Alsace-Lorraine,

extending through Soultz-sous-Forets, Pechelbronn and Lamperts-
loch. 46 They occur as asphalt-impregnated limestone and sandstone
associated with lignite. Petroleum is also found locally. The asphalt
strata average about 80 ft. in thickness and carry many fossils. The

IX EUROPE 197

region is badly faulted. The bituminous limestone has the following
average composition:

Asphalt (fusing-poin t 77 F., K. and S. method) 1 1 . 9 -i 2 . 32 per cent

Calcium carbonate 69.0 -71 .43 per cent

Iron and aluminium oxides 4.3 - 5.9 per cent

Sulfur 5.0-5.6 per cent

Magnesium carbonate 0.3 per cent

Silica 3 * * 5~ 3-65 per cent

Loss, etc * 1.7 - 3.4 per cent

The asphaltic sandstone at Pechelbronn occurs in veins 3 to 6 ft.
thick, containing 1518 per cent of a soft, viscous asphalt associated
with 82-85 per cent of sand. The asphalt when extracted shows a
gravity between 0.90 and 0.97 at 77 F. Large quantities of as-
phalt have been mined in this region for paving purposes,

SPAIN

Burgos Province. At Maesta there has been reported an as-
phalt deposit containing: 8.80 per cent asphalt, 68.75 per cent SiO 2 ,
9.15 per cent CaCO 3 , 8.10 per cent MgCO 3 , 4.35 per cent Fe 3 O 3
and Al 2 O a , and 0.85 per cent water and loss.

GERMANY 47

Province of Hanover. At Limmer, a small village near Ahlem
in the plains of Acker, about 18 miles west of Hanover there occurs
a deposit of asphaltic limestone measuring 1600 by 2250 ft. which
was discovered by Dr. Eirinis d'Eyrinys about 1730 and first mined
in 1843 by D. H. Hennig. 48 The rock carries between 8 and 20
per cent of asphalt and contains numerous fossil shells. As freshly
mined it has a brownish to gray-brown color, and the asphalt im-
pregnation is very soft in consistency containing a large proportion
of volatile constituents. The average analysis shows:

Asphalt 8 . 3 per cent

Calcium carbonate 56 . 5 per cent

Magnesium carbonate , 27 . o per cent

Iron and aluminium oxides 8.2 per cent

Total 100. o per cent

The richer portions of the vein test as follows :

Asphalt (fusing-point 61 F. s K. and S. method) 13.4-14.3 per cent

Calcium and magnesium carbonates 67 per cent

Iron and aluminum oxides, etc 17- 5~ J 9* 5 P er cent

t ...,., * 0.3- 1.18 per cent

198

ASPHALTS ASSOCIATED WITH MINERAL MATTER

At Waltersberge, near Limrner, a very large deposit of asphaltic
limestone is found, containing 5 to 7 per cent of asphalt* It is esti-
mated that about 3,000,000 tons occur in this deposit, but the ma-
terial is so poor in asphalt that it must be enriched before it can be
used for paving purposes, although it has not given good results as
such, on account of the large percentage of clay present

/,-/;//';

'" t f A'- 1

W% f ' 7 '

10 10 20 30 40m.

i..,,.,.,,! ^ ^^^^

1 : 1500
FIG. 64. Herzog Wilhelm Mine at Holzen, Germany.

In the District of Holzminden, in the Dukedom of Braun-
schweig, a short distance west of the village of Holzen, on the west
bank of the River Ith, there occurs one of the most productive de-
posits in Germany, which has been identified with the neighboring
towns of Eschershausen and Verwohle, 49 discovered in 1601 by
woodsmen, who first utilized the substances as fuel. This includes
the u Herzog Wilhelm" mine, the u Augusta Victoria," "Verwohle,"
"Greitbergbruch," "Wintjenberg" and "Stolln Gustav" quarries,
the first two of which are illustrated in Figs* 64 and 65. A plan of
the entire region is shown in Fig. 66. The deposits consist of as-

IX EUROPE 199

phaltic limestone, containing 10 per cent asphalt at the top, which
gradually diminishes to 3 per cent at the lower levels, averaging 6
to 8 per cent, and characterized by the presence of fish scales.

The asphalt stratum has been traced for approximately 14,500
ft. and forms a succession of layers 65 ft thick carrying a variable

FIG. 65. Augusta Victoria Quarry at Holzen, Germany.

percentage of asphalt associated with limestone, and separated by
clay and shale. The average asphalt analyzes as follows :

Asphalt (fusing-point 65-7o F., K. and S. method) ... 5-4 - 8 . J per cent

Calcium carbonate 80.0 -90.9 per cent

Iron and aluminium oxides 4.0-5.0 per cent

Silica 2. 55- 4-77 P^ cent

Loss o. 15- a . ii per cent

The Verwohle rock asphalt shows the following average com-
position :

(Test 7) Specific gravity at 77 F 2.326

Voids 2.8 per cent

(Test 21) Soluble in carbon disulfide 7 -.73 P er cent

Non-mineral matter insoluble o . 60 per cent

Mineral matter 9* -67 per cent

200

ASPHALTS ASSOCIATED WITH MINERAL MATTER

Legend.

Deutsche Asphalt Ahtien GeseUsckaft (Eschershausen).
Hannoversckt Baugesettschaft Akt. Ges. (Hannover}.
Indus tr it gesellschaf t G. m. b. UJttr Steine u. Erden. (Etcher shavsen).
VorwoUer Asphalt Co. Limited (Eschershauscn).
Union Co.

Vorwohkr Asphalt Fabrik L. Hoarmnn u. Co. G. m. 6. JET.
Asphdt Con-panic Limited.
Tkomae.

Herkulcs Gcwerkschaft*
Bits Kalkwrk.

FiG. 66. Verwohle and Escherahausen Asphalt Deposits, Germany.

IX EUROPE 201

The extracted asphalt tests as follows:

(Test 7) Specific gravity at 77 F f 1 .019

(Test 9^) Penetration at 77 F 95

(Test 13) Fraas breaking-point Below 20 C.

(Test 15^) Fusing-point (R. and B. method) 47 C.

(Test 15^) Ubbelohde drop-point 57 C.

(Test 28) Sulfur i . 67 per cent

This material must be enriched by the addition of Trinidad,
Limmer, or petroleum asphalt, before it becomes suitable for con-
structing pavements. It is marketed in three forms, viz. :

1 I ) Mastic cake, which is prepared by first grinding the rock
asphalt to a powder, which is heated to 180-200 C. for 4-6 hours,
whereupon sufficient asphalt is added to enrich same to 14-16 per
cent, and finally cast into the form of cakes, suitable for use in
mastic work.

(2) Powder, which is prepared by heating the ground rock
asphalt in steam-jacketed kettles to 80 C. with an "enricher" and
under strong agitation, until it forms so-called "clinker" containing
about 1 1 per cent asphalt, which in turn is cooled and ground to a
powder, suitable for use under compression to form sheet-asphalt
pavements.

(3) Asphalt-tiles, which are made by heating the ground rock
asphalt and compressing same into plates 28 by 25 cm. and 1.5 to
6.0 cm. thick by means of hydraulic presses operating at 180 to 400
atmospheres. The resulting tiles are used for surfacing factory
floors, bridges, viaducts, etc.

A small deposit has been reported at Wintjenberg in this same
neighborhood, but has not been worked to any extent.

Province of Westphalia. Minor deposits have been found near
the villages of Darfeld, Buldern, Hangenau, and Appelhiilsen, asso-
ciated with clay and shale.

Province of Hessen. At Mettenheim 50 between Worms and
Appenheim, occurs a deposit of asphaltic limestone and clay carry-
ing a large quantity of fossil fish remains. The rock contains be-
tween 74.4 and 82.6 per cent of asphalt of a comparatively high
fusing-point.

Province of Baden. Minor occurrences have been reported
near Dossenheim, north of Heidelberg, 51 also near Ottenau, north-
east of Baden-Baden. 52

202

ASPHALTS ASSOCIATED WITH MINERAL MATTER

Province of Silesia. Asphalt has been found in the granite of
Striegau and in the northern part of the Black Forest, associated
with calcite and hematite, 53

JUGOSLAVIA

Province of Dalmatia. 54 A deposit of asphaltic limestone occurs
at Vrgorac, having a specific gravity at 77 F. of 1.697 containing
an average of 26 per cent of asphalt. Analyses show the following
ingredients :

Analysis I,
Per Cent

Analysis 2,
Per Cent

Analysis 3,
Per Cent

Asphalt

2.94

7.12

38.92

Silica. ... .

21 .70

Iron and aluminium oxides

7 12

<8. 10

Iron carbonate

I . IO

Calcium carbonate

l6.6o

61.08

Magnesium carbonate

12. C8

Sodium chloride

O. 07

Water

4. 10

Total

lOO.OO

99.87

IOO.OO

The first analysis represents an asphaltic limestone, containing
silica, the second analysis represents an asphaltic shale, and the
third an asphaltic limestone (pure) . Considerable asphalt has been
derived from this deposit for paving purposes.

Asphaltic shales have been reported near the town of Skrip, on
the Island of Brazza, situated about I mile from the mainland, in
the Adriatic Sea, containing between 5 and 40 per cent of soft as-
phalt, analyzing as follows: asphalt 7.1 per cent, calcium carbonate
58.1 per cent, calcium sulfate 32.6 per cent, silica 2.1 per cent, and
undetermined o. i per cent. The layers are between 2 and 4 ft. in
thickness. There also occurs a deposit of asphaltic limestone con-
taining about 13 per cent of asphalt and 87 per cent of calcium
carbonate, having a brownish-black color and containing a substan-
tial proportion of volatile matter.

At Morowitza near Sebenico, on the Adriatic Sea, occurs a
deposit of asphaltic limestone carrying 10 to 15 per cent of asphalt,
95 per cent of calcium carbonate, and about 4 per cent of mag-
nesium carbonate.

IX EUROPE 203

At Porto Mandorlo, near the town of Trau on the Adriatic Sea,
occur beds of crystalline limestone of a brownish color containing
9.2 per cent of asphalt and 90.8 per cent of calcium carbonate.
Further deposits have been located in this region at Biskupija and
Vinjisce, also at Suhidol, Bua and Dernis-Knin.

Province of Herzegovina. 55 A deposit of asphaltic limestone
occurs at the village of Popovo Polje, having a black to grayish-
black color, and carrying between 1 6 to 20 per cent of asphalt It
contains a large percentage of volatile matter, which causes the
crude material to ignite very readily and burn with a luminous flame.

A little south of the village of Misljan, and east of, the town of
Popovo Polje, occurs another and larger deposit of asphaltic lime-
stone 6 to 20 ft. thick. The asphaltic impregnation is sticky and
semi-liquid, varying between 3 and 35 per cent The richer varieties
ignite readily and burn with a luminous, smoky flame.

A deposit of asphaltic limestone about 100 ft wide and 10 ft.
thick occurs at Dracevo, about 2 }/2 miles east of the city of Met-
kovic. The rock is of a brownish black to dull black color, carrying
5.4 per cent of asphalt It is not rich enough to be worked
profitably.

Province of Styria (Steiermark). Traces have been found at
Trenchtling, northeast of Trofaiach, and in the neighborhood of
Messnerin. 56

AUSTRIA

Province of Tyrol. 57 A very peculiar asphaltic shale occurs at
See f eld, 5000 ft. above the sea-level, in beds several feet thick with
numerous fossil fish remains, in between layers of dolomite. This
deposit constitutes one of the main sources of supply of ichthyol,
which is recovered upon subjecting the material to a process of
destructive distillation in suitable retorts. The material best suited
for this purpose is composed of the following:

Asphalt 26,41 per cent

* Calcium and magnesium carbonates 38 . 22 per cent

Clay 6.67 per cent

Silica * 9 . 03 per cent

Iron oxide 5, 95 per cent

Loss and moisture 3-7^ per cent

Total loo.oo per cent

204 ASPHALTS ASSOCIATED WITH MINERAL MATTER DC

HUNGARY 5S

Province of Bihar. Deposits occur at Tataros, Derna and
Bodonos, located east and northeast of the town of Nagy-Varad
(Grosswardein), between the Sebes Koros and Berettyo Rivers.
The Tataros deposit consists of sand containing a soft, sticky as-
phalt with a characteristic, penetrating odor, which has been ex-
ploited under the name u Derna Asphalt.'' It i$ associated with a
consolidated sandstone in strata between 6 and 25 ft thick, 5000
ft. long and 4000 ft. wide. Large quantities of asphalt have been
mined from this deposit, which constitutes one of the largest sources
of supply iniiungary. Analysis shows between 15 and 22 per cent
asphalt, fusing at 83 F. (K. and S. method). The water-extrac-
tion process has been used to separate a semi-liquid asphalt from
the sand, leaving a residue containing 3 per cent of asphalt which
could not be separated. The pure, soft asphalt thus separated is
distilled to recover the heavy oils and the residue, comprising about
44 per cent of the extracted asphalt, is converted into mastic by
mixing with limestone. The product has been used with success for
paving the streets of Budapest. During the World War, the puri-
fied asphalt was shipped to Germany and used in the manufacture
of rubber goods.

A short distance east of Felso Derna there occurs a bed of sand
asphalt, very similar in character and composition to that found at
Tataros, carrying 15 to 22 per cent of asphalt. The extracted as-
phalt contains 0.73 per cent of sulfur, 5.4 per cent of ash, and 1.6
per cent of crystallizable paraffin/ 9

CZECHOSLOVAKIA

Province of Trecsen. At Strecno, on the River Waag, near
Zsolna (Sillein), at the foot of the Lipovec Mountains, there occurs
a deposit of dolomitic limestone containing 6.0 per cent asphalt, 60
fusing at 37 C. (K. and S. method) . The asphalt contains asphal-
tic acids 1.37 per cent, asphaltenes 2.11 per cent, asphaltic resins
41.29 per cent, and oily constituents 51.25 per cent. 61

Provinces of Moravia and Silesia. Occurrences of rock asphalt
have been reported at Malenowitz and Zin (northeast of Napa-
gedl), Palkowitz, Chlebowitz (near Friedek), Wiseck (near Letto-
witz),etc.

EUROPE

205

RUMANIA

At Matitza, on both sides of the Matitza River, there occurs a
large deposit in veins 30 to 40 m. thick. It is brittle at ordinary
temperatures, has a dull, dark color, and a characteristic odor. The
material contains 25 to 33 per cent asphalt, having a specific gravity
of 1.07 to 1.09 at 77 F., and a fusing-point of 41 C. (K. and S.
method). An average analysis shows: water 4.36 per cent, asphalt
30.23 per cent, silica 41.10 per cent, iron and aluminium oxides
1 8.08 per cent, calcium carbonate 4.43 per cent, and the balance
sodium and potassium salts. Large quantities of paraffin wax are
produced upon distillation. 62

ALBANIA

Selenitza (Selinitea). A fairly extensive vein of hard asphalt
in lenticular form occurs at Selenitza, 25 km. west of Valona
(Avlona), near the junction of the Vojutza (Vojusa) and Sauchista
Rivers, close to the railway line. This deposit was first mentioned
by Aristotle (384-322 B.C.), and subsequently described in detail
by the Roman writer Aelianus Claudius (Aelian), about 100 A.D. 88
It has been used for paving compositions, for manufacturing paints
and composition roofings. Between 4000 and 6000 tons are pro-
duced annually. It is on the border line between true asphalts and
"glance pitch," and tests as follows: 64

Test

No.

Description

Refined
S616nitza

Extracted
Asphalt

Color in mass

Glossy black

Fracture

Conchoid al

Streak

Black

Specific gravity at 77 F

1.21

1 .080

Penetration at 77 F ,

ioa

Ductility at 77 F

i ^

Fraas breaking-point

>77F.

I C/2

Fusing-point (K. and S. method) - *

210 F.

217 F.

* j**
ic

Fusing-point (R. and B. method)

264 F.

*o l *

2$iM 9 F,

* j v

I eh

Ubbelohde drop-point * . . . ,

284 F.

20CF.

*j f *

Volatile at 325 F., 5 hrs

0.0%

Loss (D.I.N. method)

0.6%

0.7%

Flash-point (open-cup)

566^ F.

?6c F.

Burning-point r ,..,.

628 F.

628 0? F*

Soluble in carbon disulfide . , , ,

84.62%

QQ . 86%

Non-mineral matter insoluble , ,

0,20%

yy uv /Q
o.00%

Mineral matter (ash)

I<M8%

O.I4%

Total

100,00%

IO6. 00%

206

ASPHALTS ASSOCIATED WITH MINERAL MATTER

Test
No.

Description

Refined
S&gnitza

Extracted
Asphalt

Sulfur

6.2C%

7.4.0%

Solid paraffins:
Alcohol-ether-fullers 1 earth

O <Q%

0.70%

Alcohol-ether-sulfuric acid

o. ?8%

Alcohol-ether-D.I.N. method

0.4.0%

Tja

Acid value

^35

2.QO

3$c

Asphaltenes

18 20%

AC 2O%

l&d

Asphaltic resins

I< QO%

1 8 80%

JWt*
38*

Oily constituents . , ,

20 . 70%

2A . CO%

Soft asphalt! c constituents

Q 72%

II CO%

Total

84.52%

100.00%

Solid paraffins in oily constituents

1.72%

2.01%

ITALY 65

The general location of the asphalt deposits in Italy are shown
in the map illustrated in Fig. 67.

Compartment of Marches.

Province of Pesaro ed Urbino. Impure, solid asphalt is found
at Sant' Agata Feltria associated with sulfur, but is not mined ac-
tively. At Tallamello and Urbino, deposits of solid and semi-liquid
asphalt occur associated with more or less sulfur. These are of no
commercial importance, but are of interest merely from a geological
standpoint

Compartment of Abruzzi e Molise.

Province of Chieti. In the neighborhood of San Valentino,
extensive deposits of asphaltic limestone have been worked in strata
2,1/2 to 3 miles long and about 100 ft. thick. Quarries have been
opened up in the Valley of the Pescara River at the villages of
Roccamorice, Abateggio, Manopello, Lettomanopello, Tocco, and
Papoli. Three distinct zones are distinguished. The lower carries
between 9 and 10 per cent of asphalt, the middle an average of 17
per cent, and the upper 9 to 30 per cent In certain localities the
asphalt has a rubbery consistency, and is deep black in color, and in

EUROPE

207

ASPHALT DEPOSITS

FIG. 67. Map of Italian Asphalt Deposits.

208

ASPHALTS ASSOCIATED WITH MINERAL MATTER

others it is very soft and semi-liquid. The deposits are rich in fossil
shells. Analyses show the following composition : 66

San
Spin to,

Per Cent

Piano
dei
Monaci,
Per Cent

Cusano,
Per Cent

San
Giorgio,

Per Cent

Acqua-
fredda,

Per Cent

Fonti-
celle,

Per Cent

Letto-
mano-
pello,
Per Cent

Rocca-

morice,

Per Cent

Moisture

0.64

10.72
82.25
5.50

0.40
11.70
62,23
24.80

0.98
15.70
49.70
32.00

0.46
12.06

85-30
i .40

0.66
10.62
86.40
1.50

O.22
10.96

86.00

I .20

Asphalt

7.15
73-76
14.26
1.72
3.02
o.n

12.46
77-53
4-71
2.63
2.17
0.50

CaCOj

MgCOi

CaSO 4

Clay

0.74
0.15

0-37
0.06

0.44

0.32
0.42
0.82

0.16
0.42

0.20

0,52
0.30

1.18
0.32

SiOi

These deposits are especially suited for pavements in tropical
climates and have been used with good results in Cairo, Bombay,
Rio de Janeiro, etc. A number of mines have been opened up along
this valley amidst precipitous mountains attaining elevations up to
10,000 ft. The rock asphalt is transported by aerial ropeway and
narrow gauge surface tracks and the development has been effected
in the face of great natural difficulties.

Compartment of Calabria

Province of Baslllcata (Potenza). Asphaltic limestone pros-
pects have been reported at Tamutola, Magliano Setere and
Leviano.

Compartment of Campania

Province Terra dl Lavoro (Caserta). One of the largest as-
phalt quarries in the entire region, which, however, has not been
very active in recent years, occurs at Colle San Magno. Analyses
of the product as mined show it to be composed of the following :

Asphalt 7. 15 per cent

Calcium carbonate 73 , 76 per cent

Calcium sulfate i . 72 per cent

Iron and aluminium oxides 3 .02 per cent

Magnesium carbonate* 14. 24 per cent

Silica, o. 10 per cent

Prospects of asphaltic limestone occur, at Liri, Frosione, Monte
San Giovanni, Banco, Castro dei Volsci, Filletino and Collepardo.

IX EUROPE 209

Compartment of Sicily

Province of Syracuse* 7 The largest and most important Italian
asphalt deposit occurs at Ragusa, about 8 miles from the southern
coast of Sicily, on the River Irminio, in a bed 10 to 50 ft thick and
1600 to 2000 ft. long. It was discovered in 1838 and first utilized
for building stone, and later, about 1856, exploited for compressed
asphalt work. Fig. 68 shows a general view of the principal mine,
Fig. 69 illustrates the tunnelling operations, and Fig. 70 shows the
rock asphalt sawn into blocks and slabs as it is blasted from the
deposit. The rock contains variable percentages of asphalt, ranging

nu 05. /ispnait mine at Kagusa, Italy.

from 2 to 30 per cent, associated with a soft consolidated limestone
composed largely of fossil shell remains. Several grades of rock
asphalt are mined, including a brown variety relatively poor in
asphalt, carrying between 3 and 7 per cent, also a black variety
carrying about 15 per cent. Commercial grades usually contain 6
to 10 per cent, and occasional pockets are encountered running as
high as 12 to 1 8 per cent. The rock containing 6 to 9 per cent is
marketed for use as mastic, and the leaner varieties containing an
average of 3 per cent of asphalt are distilled in retorts to recover
the oils. In 1924, there were 16 furnaces in operation, yielding
30,000 tons of distillate per annum. The retorts are arranged in
groups of four. Each oven is 15.5 meters high and of rectangular

210

ASPHALTS ASSOCIATED WITH MINERAL MATTER

cross section. The waste gases are used to promote combustion of
the rock. The maximum temperature is about 730 C. and the
distillation zone ranges from 200 to 600 C. The distillate is
practically free from paraffin and contains up to 2 per cent phenols.
It compares with crude petroleum of Ohio and Texas origin. To

FIG. 69. Tunnelling Operations at Ragusa Mine.

obtain I ton of distillate, 1 8 to 20 tons of asphaltic rock are re-
quired. The distillate is refined with sulfuric acid and fractioned
into different grades of lubricating oil. 68 These deposits have been
worked for many years, and over 100,000 tons are mined annually
for use on the continent of Europe. The material as mined requires
no further treatment, other than grinding. It is shipped from the

IX EUROPE 211

ports of Siracuse, Mazzarelli and Catania. Analyses show the fol-
lowing compositions :

Range Average

Per Cent Per Cent

Asphalt 8.80-14.05 9.24

Calcium carbonate 82.15-88.21 87.98

Iron and aluminium oxides 0.91 1.90 0.93

Magnesium carbonate 0.96 0.72

Silica o . 60- o . 73 o . 69

Moisture and loss 0.40- i . 17 0.76

The extracted asphalt shows the following penetrations (Test
9&) : At 77 F. too soft; at 60 F. 168; at 50 F. 94; at 40 F. 50.
The fusing-point (Test i$b) ranges between 36 and 44 C.

FIG. 70. Sawing Ragusa Asphalt into Blocks.

The rock asphalt is also removed in large blocks which are
capable of being sawed, bored, or carved in the form of paving
stones, stair treads, or ornamental work for buildings. The dark
color of the asphalt as freshly mined soon disappears upon expo-
sure to the weather, turning to a bluish gray.

Smaller deposits occur at Modica and Scicli, south of Ragusa,
in the same region, testing as follows: moisture 0.60 to 0.72 per

212 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

cent, asphalt 9.00 to 9.50 per cent, CaCO 8 87.27 to 86.78 per cent,
Fe 2 O 3 2,05 per cent, SiO 2 0.78 to 0.72 per cent, and loss 0.30 to
0.23 per cent. Asphalt is abundant in the basalt at Cozzo Grillo,
near Cape Passero, at the southeastern tip of Sicily, also at Vizzini,

north of Ragusa.

GREECE 6 *

Department of Triphylia. At the village of Marathonpolis, on
the west coast of the Pteloponnesus District, there occurs a deposit
of asphaltic limestone well suited for the preparation of asphaltic
mastic pavements, analyzing as follows: asphalt 14.75 per cent, si-
lica 1.07 per cent, iron and aluminium oxides 0.80 per cent, calcium
sulfate 0.21 per cent, magnesium carbonate 0.45 per cent, calcium
carbonate 82.27 per cent, moisture and loss 0.45 per cent This de-
posit is shown in Fig. 71, location 2.

Department of Achaia (Peloponnesus District). Asphalt has
also been reported at location 3, likewise at location 4 (Fig. 71)
near Divri, south of Mount Olonos, and north of the town Souli.

lolian Islands. Liquid asphalt deposits occur on the island of
Zante (Zacynthus or Zakynthos) at location 5 (Fig. 71 ), 70 and
asphaltic limestone on the islands of Paxos and Antipaxos, as shown
at location 6.

Department of Phocis. A deposit has been reported near
Galaxidi, shown at location 7 (Fig. 71).

Department of Phthiotis. Occurrences are found near Dremisa
(Dramesi) as indicated at location 8 (Fig. 71).

Departments of Eurytania and Arta. Occurrences of soft
asphalt and asphaltic limestone are found in the Pindus Mountains,
up to the town of Pinde, as shown in locations 9, 10, n and 12
(Fig. 71). Location n is at Vordo, in the valley of the Molitsa
River, a branch of the Kalamas River.

Northern Departments. Various outcrops of asphalt have been
found at Bajousous (location 13), Lavdani (location 14) and
Eleousa (location 14), in the Northern Provinces, Fig 71.

, PORTUGAL

Province of Estremadura. At Serra de Cabagoa deposits of
asphaltic sandstone have been reported, and at Monte Real, north
of <Leiria, layers of asphaltic sandstone impregnated with a very

EUROPE

213

soft and viscous asphalt exist None of these have been worked to
any great extent An asphalt pit, known as "Azeche," was formerly
worked south of Nuestra Senora de la Victoria. 71

25 50 75 100

I ii db
KILOMETRES

FIG, 71. Map of Greek Asphalt Deposits.
SPAIN r2

Province of Santander. In the neighborhood of Puerto del
Sscudo, deposits of asphaltic sandstone are found in beds about 5 ft.
:hick. No analyses are available. At Suances similar deposits of

214 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

asphaltic sandstone have been reported containing approximately
1 1 per cent of asphalt, also in the Reviere of Lucara.

Province of Alava. At Alauri, Maestu, and other localities in
the Pyrenees, asphaltic sandstone deposits containing 12 to 20 per
cent of asphalt have been worked for a number of years. A mine
about 10 miles from Vittoria consists of a calcareous sandstone in>
pregnated with 8 to 9 per cent of asphalt. It shows the following
average composition:

Asphalt 8 . 80 per cent

Silica 68.75 per cent

Iron and aluminium oxides 4.35 per cent

Calcium carbonate 9. 15 per cent

Magnesium carbonate 8.10 per cent

Water and loss 0.85 per cent

Province of Navarre. Similar deposits have been reported at
Bocaicoa, which have been worked to a limited extent.

Province of Gerona. Asphalt and asphaltic shales have been
found in the neighborhood of Can Dabano, associated with ozo-
kerite. The asphalt melts at 61.5 C. (K. and S. method).

Province of Tarragona. Asphalt occurs in the District of
Campius, in the precipices of Montseng, also at Sot del Bosch, Port
B6, Can Call, Sot de Puig and El Sotas. Likewise in the District
Manresa in the Santa Catalina Mountains. Asphaltic shales occur
in the District Saedes *at Ribas de la Pega, Serrat Negre, Clara
and Canal de Dordella.

Province of Soria, At Santander, Sierra de Frentes, and
Fuente-toba-Cidones, 73 several deposits of asphaltic sandstone have
been operated, from which fairly large quantities have been mined.

Province of Burgos. In the Reviere of Huidobro, Asphalt pits
have been worked at Narcisa and Felicia.

Province of Almeria. Asphalt has been reported at Cobdar,
Tijola and Bayarque.

Province of Valencia. Asphalt has been reported at Mogente.

RUSSIA (IN EUROPE)

Simbirsk Province. The principal occurrences are found along
the banks of the Volga River in the vicinity of the estuaries of vari-
ous small streams, including the Syzranka, extending to Samarskaya-

IX EUROPE 215

Louka, between the village Perewoloki and the city Syzran. These
contain 6-13 per cent asphalt (rarely 37 per cent) associated with
dolomite. In the same region, north of Samarskaya-Louka and
3 km. from the Volga River, there occurs a deposit containing 6-20
per cent asphalt associated with sand, known as "garj," covering an
area 1300 by 320 ft., in a layer 32 ft. deep. The extracted asphalt
has a fusing-point of 96-147 C. T5

Kazan Province. Deposits have been reported at Chistopol on
the Kama River.

Samara Province. Asphalt is found at the mineral wells at
Sergievsk, also at Sarabik-Ulowo and Chugorowo in the vicinity of
Bugulma. Deposits are found near Samara, at the hair-pin bend of
the Volga, also at Tzarevstchina and on the banks of the Krunza
and Oussa Rivers, between Kostyachi and Petcherskoi'e.

Terek Province (Northern Caucasia). At Vladikavkaz there
occurs a deposit containing 612 per cent soft asphalt associated
with earthy matter. This is known as "kir" when found in a fairly
pure state, and "katran" when associated with much mineral mat-
ter. Also 4 km. north of Staniza-Miailovskaja there occurs a de-
posit in a ravine of the mountain Besimyannya-Gora, containing 70
to 86 y^ per cent asphalt associated with clay. The extracted as-
phalt is hard and brittle, melting at about 300 C, and has a specific
gravity of about i.2. 76 Deposits also occur at Goriatchevodsk, like-
wise on the banks of the Little Chetchna River, between the Terek
and Argun Rivers. Asphaltic sands, sandstone and clay occur near
the town Sernowodsk. North of the Groznyi oil fields there occurs
a deposit containing 6 to 1 2 per cent asphalt, likewise several small
deposits on the Groznyi and Terek rocky prominences in the vi-
cinity of the oil wells.

Kutais Province (Transcaucasia). In the vicinity of Sukhum, on
the left bank of Bzyb River, there occur veins of asphalt in dolomite,
in the Bsyschro basin. Near Ozurgeti, about 3 km. north of the
railroad station Notanebi there occur deposits of asphaltic sandstone
containing 20 per cent asphalt. A large deposit occurs i km, from
the left bank of Supsa River, near where it empties into the Black
Sea, to the west of Chrialeti mountain. Deposits are reported near
the village Guriamta and asphaltic sands in the vicinity of Tamara-
sauli, likewise in the valley of Bekwis-Zchali River, near the town

216 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

Bekwi, also at the village Dsmuisi about 25 km. northeast of the
city Kutais*

Tiflis Province (Transcaucasia). Asphalt deposits occur in the
neighborhood of Gori, also the village Dschawa at the overflow of
the Big Ljachwa River. Near Signach, about 2 km. northeast of
the Mirsaani oil field, in the Kwamianzkaro ravine, there occur four
veins of hard asphalt containing 26.3-30.6 per cent ash. Asphaltic
sandstones are found on the right bank of the Yora River near
Chatma, Kapitschi, and in the rocky prominences of Eilar-Augi near
the town Kasaman.

Baku Province (Transcaucasia). Near Baku there are a num-
ber of deposits of asphalt in the vicinity of the oil wells, and in the
region of the numerous large mud volcanos. In the Adzhikabul
(Adza Kabul) district, about 75 km. southeast of Baku, a deposit
of rock asphalt has been reported containing 42-67 per cent soluble
in carbon disulfide. The extracted asphalt has the characteristics
of gilsonite, testing as follows : 77

(Test 7) Specific gravity at 77 F 1.026-1.081

(Test 9^) Penetration at 77 F o to 9

(Test 15^) Fusing-point (R. & B. method) 196-268 F.

(Test 19) Fixed carbon 13.6-15.9 per cent

On the Island Suyatoi there is an area of about 14 hektar cov-
ered with asphalt, which however is not utilized.

ASIA

SYRIA (LEVANT STATES) 78

The deposits which follow are indicated on the map shown in
Fig. 72.

Vilayet of Aleppo. Various deposits of asphaltic limestone have
been reported about 5 miles south of Alexandretta, also near An-
takia (Antioch).

f Vilayet of Beirut At Jebel Keferie (Jebel Kfarieh), a hill near
the bend of the Nahr el Kabir, near the town Babenna, about 38
km. from the sea, on the road between Latakia and Aleppo, exten-
sive deposits of asphalt are* found covering an area of 1400 by
1500 m., estimated to contain about 2,000,000 tons. Most of these
consist of a dolomitic marl (containing 28.0 per cent silica, 2.9 per
cent MgCO 8 and 3.0 per cent clay) with asphalt, of which 21.0 to

ASIA

217

FIG. 72. Map of Asphalt Locations in Syria and Palestine.

218 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

23.6 is soluble in carbon tetrachloride and 10.9 to 10.3 per cent of
the non-mineral matter remains insoluble. The bituminous con-
stituents are associated with 68.1 to 66.1 per cent mineral con-
stituents (total = 100 per cent). These deposits have not been
worked to any extent, on account of the difficulty in transportation
to the coast. 79 They occur in three separate valleys or canons, i.e.,
Chandak bu Sfgherie, Chandak Shehade, and Chandak el Barbura;
likewise on the neighboring mountains, Jebel Harf and Jebel Nobeh.
Similar deposits, but of a smaller size, pccur west of the foregoing,
and north of a small canon through which the Nahr el Kebir passes,
at Dahana (Derhana, or Derk'ah'a), consisting of limestone and
serpentine impregnated with asphalt, of which 10.7 to 12.3 per cent
is soluble in CC1 4 ; also at Milik, consisting of asphaltic marl, of
which 6.93 per cent is soluble in CC1 4 and 4.34 per cent non-mineral
matter remains insoluble; likewise at Jebel Sullas (Sulas), consist-
ing of limestone and marl impregnated with asphalt, of which 6.99
per cent is soluble in CC1 4 A still smaller deposit lies north of the
last three, at Djukr Djak, near Kabara. Still another deposit oc-
curs close to the city of Beirut, and a small one near Tyre (Es Sur).
Other deposits are reported at Ain Ibl (Ain Ebel) 20 miles south-
east of Tyre; at Aidib (Aideb) 15 miles east of Tyre; and at
Hereika. 80

Vilayet of Sham (Syria). 81 Asphaltic limestone deposits are
reported at Khaliwet, between Hasbaya (Hasbeya) and Rashaya
(Rasheye), also at localities 5 miles southeast of Hasbaya; another
10 miles south of Hasbaya; another at Sohmor (Sahmur) 10 miles
north of Hasbaya on the eastern bank of the Nahr Litani ; another
at Ain-et-Tineh 7 miles north of Hasbaya on the western bank of
the Nahr Litani; and still another 4 miles north of Hasbaya at Ain
Tannura (Ain Tadjoura). Asphaltic limestone deposits occur in
the Yarmuk (Jarmuk) River valley, along the Damascus-Haifa
railroad, at Marani (Mrani) containing 10 to 30 per cent asphalt;
also at El-Makarin (Mekarim) containing 18 to 20 per cent asphalt.
Rock asphalt also occurs northeast of Latakia, north of Horns, and
about 25 miles west of Tyre.

Palestine. Deposits of asphaltic limestone occur at the Sea of
Galilee (Lake Gennesaret, or Bahr Tubariya), at Tubariya (Ti-
berias) and Hammath (Amman, Hamath, or Hammam) on the

IX ASIA 219

western shore, also at Muskes on the River Jordan south of the Sea
of Galilee* Asphaltic limestone deposits also occur at the Dead Sea,
the largest being at Nebi Musa (Neby Musa) 4 miles west of the
northwest shore. This is reported to carry 4 to 6 per cent of as-
phalt and has a black color. A typical analysis is as follows : asphalt
soluble in chloroform 5.07 per cent, CaCO 3 70.20 per cent, MgCO 3
trace, CaSO 4 1.20 per cent, SiO 2 4.51 per cent, A1 2 O 3 and Fe 2 O 3
6,56 per cent, insoluble organic mattter 12.52 per cent, total 100,06
per cent. Other deposits are found on the western shore near Es
Sebba (Es Sebbe, or Es Sebeh) and Wadi Sebba (Wadi Sebeh, or
Wadi Sebbeth). A short distance from these localities, there occurs
a peculiar deposit consisting of flint pebbles cemented together with
varying percentages of asphalt, in juxtaposition to a vein of asphal-
tic limestone. Deposits of asphaltic limestone are also reported on
the eastern shore near El Kerak. On the southwestern shore, at
the foot of Jebel Usdom ( Jebel Esdom) mountain, is found a con-
glomerate carrying asphalt as the binding medium, and close to this
locality, about 300 yards from the mouth of the Wadi Mahawat
(Wadi Mayawat) stream there occurs a deposit of asphaltic lime-
stone associated with fossil marine remains, carrying 13 to 25 per
cent asphalt, which is used by the natives as fuel. 82

MESOPOTAMIA (IRAQ)

Villayet of Baghdad. At Hit, to the west of Baghdad, on the
west bank of the Euphrates River, deposits of asphaltic limestone are
still found and collected by the natives in a crude way, exactly as
was the case many centuries ago. The occurrences are found a short
distance south of Hit, between two streams, the Kubessah and the
Mohammedieh. The asphalt is collected and sold in the form of
small cakes, which the Turks call "karasakiz" and the Arabs "jir"
or "ghir" or "gir" referring to a mastic containing sand or lime-
stone. The term "seyali" is used to designate the fluid or semi-
fluid varieties of asphalt of recent origin, and the term u qasat" to
denote the ancient forms of natural asphalt. Upon being melted
and mixed with sand or earth, it is used for calking ships. Asphalt
deposits 4 to 5 m. thick are found at Tuz-Khurmatli on the west
bank of the Tigris River, about 50 miles north of Baghdad. South-
west of this locality there occurs a deposit about 2 m. thick, at the

220 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

springs of Kifri, about 2 miles east of the settlement at the foot of
Neft-Dagh (Naphtha Mountain). 88 Another deposit occurs on
Karum River, north of Dizful, a short distance north of the Persian
Gulf. Another deposit has been reported on the southeastern slope
of Jebel El-Hamrin mountain along the Tigris River.

ASIATIC RUSSIA

Uralsk Province. A deposit of asphaltic sand occurs on the road
from Chiwa and Kungrad towards Uil and Uralsky, about 25 km.
northeast of the village Tersekan, on the southern shore of a small
salt lake.

State of Turkestan. Asphalt deposits occur on the island of
Cheleken at so-called Naphtha Mountain (Neftjanaja Gora) and
in several other localities, particularly in the vicinity of Ferghana,
from which region about 1500 tons of rock asphalt are exported to
Europe annually.

Kamchatka Peninsula (Eastern Siberia). On the tundra of the
western coast of Kamchatka, north of the River Sopotschnyi, as-
phalt deposits have been reported.

Sakhalin Island. More or less developed deposits of rock
asphalt occur on the northern portion of the island.

TlJRKEY-IN-AsiA (ASIA MlNOR)

Anatolia. Several minor deposits of rock asphalt have been
reported to occur in Anatolia, 84 and at Olty (Olti) in the State of
Georgia, but these are of no particular commercial importance.

ARABIA

Vilayet of El Hasa. 85 In 1902 an extensive deposit was dis-
covered on the island of Bahrein, in the Persian Gulf, which on
analysis was found to consist of:

Asphalt. . . , aa. 77 per cent

Ash 76 . 68 per cent

Moisture ,, o, 59 per cent

Total , 100,04 P r cent

The ash consists almost exclusively of calcium-aluminium silicate.
The product is mixed with limestone powder and used for paving

IX ASIA 221

purposes. Another deposit is found near Burgan on the west shore
of the Persian Gulf and west of Ai-Koweit (Koweyt) near the town
of Benaid-el-Qar.

Sinai Peninsula. Asphaltic petroleum seepages occur at Abu
Durban and Jebel Tanka.

EGYPT

Springs of asphalt oil have been known as far back as Roman
times to exist at Jebel Zeit, termed by them "Mons Petrolius," be-
tween the Nile and the Gulf of Suez. Layers of asphaltic sand-
stone have recently been reported at Helwan, on the right bank of
the River Nile, a short distance south of Cairo. 86

INDIA

Kashmir District. Rock asphalt has been reported near Isakhel
ontheBasti River.

Hazara District, Seepages of impure liquid asphalt occur in
the Sierra Mountains at Gunda.

Baluchistan District. Asphalt seepages similarly occur at Gan-
dava and Khalan (Khar an),

Bombay Island. Deposits of u mineral pitch" and basalt have
been reported in Bombay Island, off the western coast of India. 87

CHINA

Chinese Turkestan (Sin-Kiang), In Sungaria (Dzungaria),
asphalt deposits have been reported at Lake Telli-Nor in the Dzung
Gobi, southeast of Jair Mountains; also at the Orchu Basin of the
Jeun River, on the southern slope of Jair Mountain.

JAPAN

Akita Prefecture. 88 A series of asphalt deposits occur in the
villages of Toyokawa (embracing the hamlets of Tsukinoki, Riuge,
Magata, Iwase and Urayama) and Kanaashi (embracing the hamlet
of Kurokawa}. These are situated between i to \y 2 miles east of
the Okybo railway station on the Ou railroad line, in the neighbor-
hood of Lake Hachiro and the pond Iwase. From the area cov-
ered by the deposits, about 180,000 sq. ft., it is estimated there exist
a total of 2,360,000 cu. ft in volume. They are found on the sur-

222

ASPHALTS ASSOCIATED WITH MINERAL MATTER

face of the hills about 30 to 50 meters above sea level, also among
the swamps surrounding the hills. It is apparent that this region
is underlaid with an asphaltic petroleum which seeps out between
the fissures in the shales and flows out of springs in the bottom
of the swamps or marshes. For example, in the pond Iwase, the
natives stir the bottom with a long bamboo pole, which detaches
masses of soft asphalt, which are then ladled from the water's
surface. The asphalt occurs in various forms, depending upon the

FIG. 73. Mining Asphalt at Toyokawa, Japan.

state of weathering and the associated ingredients, ranging from
a thick viscous maltha to a hard solid form associated with sand
or clay, and in swamps with the decayed remains of aquatic plants.
As the asphalt exists near the surface of the earth, it is mined by
hand with a spade or mattock, as illustrated in Fig. 73. After ex-
posing it to the sun for a while, it is melted in shallow pans to expel
the water and permit the coarse earthy matters and organic im-
purities to settle, whereupon the asphalt is cast into moulds and
marketed as such. This operation has been performed in much
the same way since ancient times. The good, rich ore is lustrous

AUSTRALIA

and black, whereas the lean, poor ore appears dull brown,
made by the author gave the following results:

223
Tests

Crude

Fluxed

Asphalt

(Test i) Color in mass

Black

(Test 2) Homogeneity

Non-homogeneous

Homogeneous

(Test 4) Fracture

Conchoid al

Conchoidal

(Test 5) Lustre

Dull

Bright

(Test 6) Streak

Brown

Black

(Test 7) Specific gravity at 77 F

1.280

1.075

(Test 9^) Penetration at 1 1 5 F

Penetration at 77 F

0-3

!5-5

Penetration at 32 F

2.3

(Test 9^) Consistency at 1 1 5 F

30-7

10.6

Consistency at 77 F

83-4

27.6

Consistency at 32 F

Over too

66.9

(Test 9^) Susceptibility index

Over 33

31.8

(Test io) Ductility at 77 F

(Test i $) Fusing-point (R. and B. )

210 F.

i54iF.

(Test 1 6) Volatile at 325 F., 5 hrs

2 . 2 per cent

2.8 percent

(Test 19) Fixed carbon

20.7 percent

20.9 percent

(Test 21) Soluble in carbon disulfide. . . .

47.72 per cent

86.88 percent

Non-mineral matter insoluble. .

36.85 percent

9.25 per cent

Mineral matter

15.43 P^ cent

3.87 per cent

Total

loo.oo per cent

(Test 22) Carbenes

0.42 per cent

0.12 per cent

(Test 23) Asphalt soluble in petroleum

naphtha

23 . 2 per cent

60.3 percent

(Test 33) Solid paraffins

0.2 percent

0.5 percent

(Test 340) Asphalt as saturated hydrocar-

bons

10.5 percent

26.8 percent

The production ranges from 2000 to 4000 tons annually.

Prefectures of Yamagata, Aomori and District of Hokkaido.
Minor deposits have been reported at these localities, but have
attained no commercial importance.

AUSTRALIA

New South Wales. Several occurrences have been reported in
New South Wales. 89

Western Australia. Minor deposits have been found in the
Ord River basin, 150 miles south of Wyndham, near the junction
of the Ord and Negri Rivers; likewise along the Stirling River. 90

Northern Territory. An occurrence has been reported at the
Waggon Lagoon, on Roper River, 350 miles east of Port Darwin. 90

224

ASPHALTS ASSOCIATED WITH MINERAL MATTER

Tasmania. Asphalt deposits have been reported between Re-
cherche Bay and New River in southern Tasmania. 81

New Zealand. Asphalt deposits have been located in the Man-
gawai and Arai Districts, between Bream Tail and Rodney Point.

DUTCH EAST INDIES

Buton (Boeton) Island. An extensive asphalt deposit occurs
on Buton Island, south of Celebes Island. 92 Illustrated in Figs. 74
and 75, Four different mines have been reported.

(1) Kaboengka, estimated to contain approximately 1,200,000
tons of asphaltic limestone,

(2) Lawele, estimated to contain 100 million tons of asphaltic
marl.

(3) Waisioe.

(4) Wariti.

The composition of the asphalt is as follows :

Kaboengka

Lawele

Waisioe

(A)

(B)

(A)

(B)

Crude Asphalt:
Water

i-S%
37-39%

0,2-!%

58-6i%

1.09-1.12
6-1 8
61-69

1 2-1 IO
23.7-29.0%

2%
26-27%

.5~ 2 %
70-72%

i. 06
65

5i '
no

24-5%

25-35%
0.5-2%

65-75%

10-20%
50-60%
2-10%
10-40%

1-5%
35~37%

0.2-1%
61-63%

I.Op
10

32
25.9%

Asphalt

Organic matter. . . , . , ,

Mineral matter. . , >

Extracted Asphalt:
SD. ffr. at 77 F

1. 06

73
47
no

25.7%

Penetration at 77 F. . . ...

Fusing-point (R. and B.) C.
Ductility at 77 F

Insol. in petr. naphtha (88).

The mineral matter of all the deposits consists of microscopic
shells (globigerina ) mixed with clay, and has the following com-
position: CaCOa 81.62-85.27 per cent; MgCO 3 1.98-3.55 per cent;
CaSQ* 0.55-1.70 per cent; CaS 0.17-0.33 per cent; combined water
1*06-2.16 per cent; SiO 2 6.95-9.15 per cent; Fe 2 O s and A1 S O 3 2.15-
3<ii p&r cent; undetermined 0.32*1*12 per cent

DUTCH EAST INDIES

225

10 20 30MU&S

74, Map of Buton Asphalt Deposits.

FIG. 75. Mining Buton Asphalt.

226 ASPHALTS ASSOCIATED WITH MINERAL MATTER IX

AFRICA

ALGERIA

Province of Oran. At Constantine, asphaltic limestone is found
in veins 32 ft. thick, containing as much as 40 per cent of asphalt.
In many places the rock is so saturated that the asphalt seeps out
and forms pools having a fusing-point of about 140 F. (K. and S.
method), a penetration of 1 1 at 77 F., and containing 0.9 per cent
of sulfur. The limestone is largely crystalline. Deposits have also
been reported at Sidi Messaoud. 93

NIGERIA

Bituminous sands are reported in southern Nigeria a short dis-
tance from the coast Attempts have been made to purify the
asphalt by the water-extraction process, but so far this has resulted
in failure. The extracted material contains about 70 per cent of
asphalt, 10 per cent of organic substances other than asphalt and
20 per cent of sand.

RHODESIA

Rock asphalt has recently been reported in northern Rhodesia
but is not thoroughly investigated. 94

MADAGASCAR

Bituminous sandstones containing 3 to 6 per cent asphalt have
been reported. 95

CHAPTER X

ASPHALTITES

Asphaltites 1 are natural asphalt-like substances, characterized by
their high fusing-points (over 230 F.). They are grouped into
three classes, namely: gilsonite, glance pitch, and grahamite. Since
all are presumably derived from the metamorphosis of petroleum,
one would naturally expect the classes to merge into one another,
and such actually proves to be the case.

The author has adopted the following means of differentiating
the three classes, one from another :

Streak

Specific
Gravity
at 77 F,

Softening-point
(K. and S, Method),
Deg. F.

Fixed Carbon,
Per Cent

Gilsonite or Uintaite . . .
Glance Pitch or Manjak*
Grahamite *

Brown

Black
Black

i .05-1 .10
i . 10-1 . 1 5
1.15-1.20

230-350
1130-350
350-600

10-20
20-30
3-55

* When substantially free from mineral matter.

In all three classes the non-mineral constituents are almost com-
pletely soluble in carbon disulfide. The physical and chemical
characteristics will be described in greater detail under the respective
headings.

GILSONITE OR UINTAITE

This asphaltite is found in but one region, 2 extending from the
eastern portion of the State of Utah across the boundary line into
the western portion of Colorado. It occurs in a number of parallel
vertical veins, varying in width from thin fissures to several feet.

Gilsonite was first discovered by the early settlers in about 1862,
at what was then known as the Culmer vein, several miles south of
the present town of Myton in Duchesne County. All of the present
veins are vertical and run from northwest to southeast. The gilson-

227

228 ASPHALT1TES X

ite runs fairly uniform in composition, and complies with the fol-
lowing general characteristics:

(Test i) Color mass Black

(Test 4) Fracture Conchoidal

(Test 5) Lustre Bright to fairly bright

(Test 6) Streak Brown

(Test 7) Specific gravity at 77 F 1.05-1.10

(Test 90) Hardness on Moh's scale 2

(Test 9^) Hardness, needle penetrometer at 115 F, 3-8
Hardness, needle penetrometer at 77 F. 0-3
Hardness, needle penetrometer at 32 F. o

(Test gc) Hardness, consistometer at 115 F 40-60

Hardness, consistometer at 77 F 90-120

Hardness, consistometer at 32 F Too hard for test

(Test 9^) Susceptibility index > 100

(Test lo*) Ductility at 77 F. (Author's Method) . . o

(Test t$a) Fusing-point (K. and S. method) 230-350 F.

(Test 15^) Fusing-point (R and B method) 270-400 F.

(Test 16) Volatile at 325 F., 5 hrs. (dry substance) Less than 2 per cent

Volatile at 400 F., 5 hrs Less than 4 per cent

Volatile at 500 F., 5 hrs Less than 5 per cent

(Test 19) Fixed carbon 10-20 per cent

(Test 21) Soluble in carbon disulfide Greater than 98 per cent

Non- mineral matter insoluble o-i per cent

Mineral matter Trace-i per cent

(Test 22) Carbenes o-J per cent

(Test 23) Soluble in 88 petroleum naphtha 10-60 per cent

(Test 26) Carbon 85-86 per cent

(Test 27) Hydrogen 8. 5-10.0 per cent

(Test 28) Sulfur 0.3-0.5 per cent

(Test 29) Nitrogen 2.0-2.8 per cent

(Test 30) Oxygen 0-2 per cent

(Test 33) Solid paraffins o-Trace

(Test 34^) Sulfonation-residue 85-95 per cent

(Test 37*) Saponifiable matter Trace

(Test 39) Diazo reaction No.

(Test 40) Anthraquinone reaction No.

Gilsonite is assorted and marketed in two varieties, known as
"selects'' or "firsts," and "seconds" respectively. The "firsts" are
taken from the center of the vein and are characterized by a con-
choidal and lustrous fracture. The "seconds" occur near the vein
walls and are characterized by a semi-conchoidal and semi-lustrous
fracture. They are graded at the mine chiefly by their appearance.
The firsts have a higher lustre, a lower fusing-point, a greater solu-
bility in petroleum naphtha, and as produced at the mines run more
uniform in physical characteristics than do the seconds. From the
middle of the Cowboy vein, there is obtained a variety of gilsonite of
unusually high lustre, having a deep black color with a bluish under-

GILSON1TE OR VINTAITE

229

tone, known to the trade as "jet gilsonite," and is used chiefly in the
highest grades of baking enamels and japans. It melts about 90 F.
higher than the "selects." The "selects" show the least tendency
to gelatinize when dissolved in solvents, the "seconds" a moderate
tendency, and the "jet" the greatest tendency. The three grades
test as follows:

Selects

Color in mass Black

Fracture Conchoidal

Lustre Bright

Streak Brown

Specific grav. at 77 F. i .044

Seconds
Black
Conchoidal
Fairly bright
Brown

'(Test i)
(Test 4)
(Test 5)
(Test 6)

(Test 7) . _. ,.

(Test go) Hardness (Moh's) 2

(Test i$a) Fusing-point (K. and S.) 230-240 F. 240-280 F.
(Test 1 5^) Fusing-point (R. and B.) 270-300 F. 275-325 F.
(Test 23) Sol. in 88 petroleum

naphtha 50-60% 20-50%

1.049

Bluish black
Pencillated
Very bright
Brown
1.076
a

320-350 F.
350-400 F.

10-20%

Figure 76 shows the hardness, tensile strength (multiplied by
ro) and ductility curves of a mixture of gilsonite and residual oil,
fluxed together so as to have a hardness of exactly 25.0 at 77 F.

100
90

70
60

?
40

32* 77 115

ttntrT~"

91.0

umumuiromim-m /

.._.. 7

lardness
"ensf/e Strength x 10
luctfltty
Point* 142 F.
itib/Iiiy/ndex*4i7

'""

'"X

Fusing
Suscef

55.0

S k

2510 s

/
/

IT-
\

% ^

*N
6

> '
a^

N
-^^

> K> 20 -50 40 50 60 70 60 90 100 110 180 150 14? 150 tt
Temperature, Degrees Fahrenheit
FIG. 76. Chart of Physical Characteristics of Fluxed Gilsonite.

(Test 9<;), equivalent to a penetration of 20 at 77 F. (Test gb).
The resulting mixture contained gilsonite, 47 per cent and resi-
dual oil, 53 per cent- The fusing-point of the gilsonite used was
285 F. (K. and S. method), and that of the resulting mixture
~

230 ASPHALTITES X

Gilsonite is one of the most valuable asphalts for manufactur-
ing paints and varnishes. Gilsonite and glance pitch mix readily
in ail proportions with fatty-acid pitches, thus differing from gra-
hamite. Products involving the use of gilsonite formed the basis
of several patents granted to S. H. Gilson, after whom the ma-
terial was named. 8

Gilsonite may be distilled until the vapors reach a temperature
of 550 F., when an exothermic reaction takes place and the evo-
lution of gaseous products becomes exceedingly rapid. The source
of heat must be reduced at this stage, but when the critical point
has been passed, the heating may be continued until the tempera-
ture of the solid coke at the bottom of the still reaches 850 F. 4
When the vapor temperature reaches 475 to 650 F. an oily dis-
tillate is obtained, which upon refining with sulfuric acid, produces
a reddish brown oil suitable for use as an oil substitute in making
paints, 5 and the sulfonation product may be used to hydrolyze fats
and oils. 6

NORTH AMERICA

UNITED STATES
Utah.

Uinta County. Practically all gilsonite is mined in the "Uinta
Basin/' at the junction of the Green and White Rivers south of Fort
Duchesne, Utah, from a point 4 to 5 miles within the Colorado
boundary line (Rio Blanco County), extending westward about 60
miles into Utah. A large number of veins have been located in this
area, extending from a northwesterly to a southeasterly direction,
and all of them parallel or nearly so. The veins vary in width
from a fraction of an inch to 1 8 ft., and some of the longest, such
as the Cowboy or Bonanza, have been traced 8 miles. The veins
are almost vertical with fairly smooth and regular rock walls, and
although they are usually continuous, they may in certain cases be
interrupted in the direction of the fissure. Very frequently branch
veins join the main one, forming very acute angles.

Near the outcrop where it has been exposed to the weather,
gilsonite loses its brilliant lustre, changing to a dull black. Along
the vein walls it shows a columnar structure, extending at right
angles to the wall, which is characteristic of all asphaltites. The

X GILSONITE OR VINTA1TE 231

rock walls are often impregnated with gilsonite */ 2 to 2 ft, so there
is no visible line of demarcation between the impregnated and non-
impregnated portions. In shale formation the impregnated zone
is smaller than when the gilsonite is found in a porous sandstone.
The following are the principal veins occurring in this region:

Duchesne Vein. This occurs about 3 miles east of Fort Du-
chesne, filling a vertical crack in sandstone and shale. The vein
has been traced for 3 miles, and is 3 to 4 ft. wide for about I y 2
miles, tapering at the ends, until it completely disappears, A com-
paratively large quantity of gilsonite has been mined from this vein.

Culmer Vein. This is also known as the "Pariette Mine,"
and occurs in the Castle Peak mining district. It has been traced
7 miles and varies in width from a fraction of an inch to 30 in.,
averaging about a foot. Several branch veins are connected with
the main one at very acute angles. It also shows a number of
transverse faults as illustrated in Fig. 77, in which the lateral dis-
placements vary from I to 10 ft. The associ-
ated rock consists of sandstone and shale.

Bonanza and Cowboy Veins. These em-
brace three veins, known as the Cowboy vein,
the East Branch and the West Branch respec-
tively of the Bonanza Vein. The last two are
joined together near the southern end. These
veins occur in sandstone and shale. The shale
being harder than the sandstone, seems to have
offered greater resistance to the intrusion of
gilsonite, and the veins are not therefore as wide
when they occur in the latter. The disappear-
ance of the veins to the northwest also occurs
in shales, and as the gilsonite passes from sand- * fr * * ***
stone into shale, it splits up into a number of FIG. 77. Faults in Gil-
smaller veinlets which gradually thin out into sonite Vein,
fine hair-like fissures. The Cowboy is the
widest vein and attains a maximum width of 18 ft., maintaining for
4 miles a width of 8 to 12 ft, as shown in Fig. 78. Its total length
is 7 to 8 miles. The Bonanza veins have similarly been followed
for 7 miles, but they are not as wide as the Cowboy.

Dragon group of veins includes the original Dragon vein, the
Country Boy and Rector veins, also the Rainbow vein abo*t 8 miles
northeast. These occur southwest of Evacuation Creek, a tributary
of the White River, near the Colorado boundary line. They extend
about 4 miles in length and average between 2 and 3 ft. in width.

232

ASPHALTITES

In some places the adjacent rock is impregnated with the gilsonite
i to 3 ft. alongside of the vein proper. In 191 1 an explosion shut
down the Dragon vein, whereupon the operatives have been trans-
ferred to the Rainbow, Country Boy, and Rector veins.

Courtesy of American Asphalt Association.
FIG. 78. View of Cowboy Gilsonite Mine, Utah.

A number of smaller veins occur in this region, including the
Uintah vein, with its branch the Little Emma vein, also the Harri-
son, Colorado, and other veins.

GILSONITE OR UlNTAITE

233

A branch railroad, known as the Uintah Railroad, about 60
miles long, runs from Dragon, Utah, connecting with the Denver &
Rio Grande Railroad at Mack, Col., and then extends to a terminus
at Watson, where the Rainbow mine is located. The product from
the Country Boy and Rector mines must be trucked 3 to 5 miles,

FIG. 79. Gilsonite Vein, Rainbow Mine, Utah.

and that of the Little Emma mine is trucked to Craig, Colorado.
These four mines were the only ones which are operated, producing
in aggregate about 130 tons daily. Figures 79 and 80 show two
typical views of the Rainbow mine.

The method of mining is very crude, and consists in digging into
the veins until a slope of 45 deg. is obtained. The gilsonite is then

234 ASPHALTITES X

dug from the face of the slope, rolled down to the bottom, sacked
and hoisted out. The hoisting is done by horses at shallow levels,
but when the mine becomes over 200 ft. deep, machinery must be
used. Since the ore is brittle, there is always a cloud of dust in the
stopes where the men work, which is soluble in the lubricating oil

FIG. 80. Interior of Rainbow Mine, Utah.

used with compressed-air mining tools, thus interfering with the
operation of such tools. Experience has therefore shown that the
production per man is greater with pick and shovel. One man can
mine and sack an average of 2 tons per ten-hour day. Fires are a
constant danger, as the dust is highly inflammable, and explosions
have been caused by a chain dropping into a pit and striking against
the rocky walls, causing sparks.

X GILSONITE OR UINTA1TE 235

Very little timber is required, as the veins are nearly vertical, and
the surrounding rock is firm and self-supporting. Boulders of rock
are frequently encountered in the veins, originally detached from
the sidewalls, and prove a serious obstacle. Blasting can only be
done where the ventilation is perfect and there is no gilsonite dust,
and it frequently becomes necessary to abandon portions of the vein
on this account. It is not feasible to work a vein less than 2 ft.
wide. It is estimated that approximately 25 million tons of gilsonite
are still available in this region.

Oregon.

Wheeler County. Minor deposits of a gilsonite-like material
have been reported by E. T. Hodge T in the vicinity of Clarno
(Type A) ; also 10 miles east of Post (on the Post-Paulina high-
way) ; also on the south bank of Pine Creek near Clarno (Type B),
testing as follows:

A" Type"B"

(Test i) Color in mass ............... Black Black

(Test 4) Fracture ................... Conchoidal Conchoidal to hackly

(Test 5) Lustre ..................... Brilliant Brilliant to dull

(Test 6) Streak ..................... Brown Brown

(Test 7) Specific gravity at 77 F ...... i .07-1 .08 1 .07-1 .08

(Test 90) Hardness ................... 2 . aj

(Test 1 5/*) Fusing-point (Note) ......... 525-550 F* 625-650 F.

(Test 16) Volatile 325 F., 5 hrs ........ o-i per cent o-i per cent

(Test 19) Fixed carbon ................ 5 . i per cent 23 per cent

(Test 21) Soluble in carbon disulfide . . . 98-99 per cent 75 per cent

Non-mineral matter insoluble 1-1.5 per cent 24. 5 per cent

Mineral matter .............. 0.5 per cent o . 5 per cent

(Test 22) Carbenes ................... i-i . 5 per cent 22 per cent

(Test 23) Soluble in 88 petroleum naph-

tha ...................... 30 per cent p per cent

NOTE. The fusing-points are somewhat high for a gilsonite, and approach that of graham-
ite. The above materials are examples of border-line cases. Both types are undoubtedly
similar materials, and Type B has been weathered, so that its original characteristics have
been altered. Huntly classes "A" as a gilsonite and " B " as a grahamite.

Crook County. A prospect has been located 38 miles south-
east of Prineville, on Sec. 33, T 16 S, R 20 E. (Willamette meri-
dian) , It occurs both inside and outside of chalcedony-quartz-calcite
geodes, also in the interstices of tuffaceous sandstone, likewise in
jasperoid rock alongside a dyke of rhyolite. It appears that the

236 ASPHALTITES X

rhyolite penetrated and fractured an oil-bearing stratum, allowing
the oil to ascend along the wall of rhyolite. It tests as follows:

(Test i) Color in mass Black

(Test 4) Fracture. . , Conchoidal

(Test 5) Lustre Very bright

(Test 6) Streak Reddish brown

(Test 7) Specific gravity at 77 F 1.162

Behavior on heating in flame Softens, froths, and burns

(Test i$a) Fusing-point (K. and S. method) 275 F.

(Test 21) Soluble in carbon disulfide 83.00 per cent

Non-mineral matter insoluble 16.39 per cent (Note)

Mineral matter o. 61 per cent

Total 100.00 per cent

NOTE. Consists of brown powder, which swells up in carbon disulfide, or when heated.

This asphaltite appears to be a metamorphized gilsonite. Only
part is soluble in residual oil (asphaltic), also linseed oil, but on
prolonged heating the insoluble matter depolymerizes and gradually
goes into solution.

ASIA

RUSSIA

Archangel Province. A hard asphaltite, closely resembling gil-
sonite, having a specific gravity at 77 F. of 1.0887 and a fusing-
point (K. and S. method) of 240 F. has been reported 8 in the
Ukhta district on the Izhma River.

GLANCE PITCH

Glance pitch resembles gilsonite in its external appearance, with
the exception of the streak, which is a decided brown in the case of
gilsonite, and black in the case of glance pitch. It also differs in
having a higher specific gravity and producing a larger percentage of
fixed carbon. It always has a brilliant conchoidal fracture, and a
fusing-point between 230 and 350 F. (K, and S. method). In
general, glance pitch complies with the following characteristics:

(test i) Color in mass Black

(Test 4) Fratture, , * Conchoidal to hackly

(Test 5) Lustre Bright to fairly bright

(Test 6) Streak on porcelain Black

(Test 7) Specific gravity at 77 F 1.10-1.15

X GLANCE PITCH 237

(Test 90) Hardness, Moh's scale 2

(Test 9^) Hardness, needle penetrometer at 77 F, o

(Test 9^) Hardness, consistometer at 77 F 90-120

(Test gd) Susceptibility index > 100

(Test 10) Ductility at 77 F o

(Test 15*) Fusing-point (K. and S. method) 230-350 F.

(Test 15^) Fusing-point (R. and B. method) 270-375 F.

(Test 1 6) Volatile at 325 F., 5 hrs. (dry substance) Less than 2 per cent

Volatile at 400 F., 5 hrs Less than 4 per cent

(Test 19) Fixed carbon 20-30 per cent

(Test 21) Soluble in carbon disulfide Usually greater than 95 per cent

Non-mineral matter insoluble Less than i per cent

Mineral matter Usually less than 5 per cent

(Test 22) Carbenes ; Less than i .o per cent

(Test 23) Soluble in 88 petroleum naphtha 20-50 per cent

(Test 26) Carbon 80-85 per cent

(Test 27) Hydrogen 7-12 per cent

(Test 28) Sulfur 2- 8 per cent

(Test 29) Nitrogen and oxygen Trace to 2 per cent

(Test 33) Solid paraffins o-Trace

(Test 34^) Sulfonation residue 80-95 per cent

(Test 37*) Saponifiable matter Trace

(Test 39) Diazo reaction No

(Test 40) Anthraquinone reaction No

Glance pitch appears to be intermediate between the native
asphalts and grahamite. It is probably derived from a different
character of petroleum than gilsonite, having nevertheless reached
a parallel stage in its metamorphosis, under approximately the same
external conditions.

NORTH AMERICA

WEST INDIES

Barbados. Glance pitch was first reported in 1750 by Griffith
Hughes, and since 1896 has been mined almost continuously. De-
posits occur in a number of localities throughout the island, espe-
cially in the Conset district, at Groves, Springfield, St. Margaret,
Quinty, and Burnt Hill. This asphaltite has been marketed under
the name of "manjak," which was originally applied to the Barbados
product, although the name was subsequently associated with a
variety of grahamite mined in Trinidad. 9 The deposits were first
worked on a commercial scale by Walter Merivale in 1896, who also
accurately described the deposit, and the properties of the mineral.

Barbados manjak contains a very small percentage of sulfur
(between 0.7 and 0.9 per cent), and about 1-2 per cent of mineral
matter. Its specific gravity at 77 F. is in the neighborhood of no>

238 ASPHALTITES X

fusing-point 320-340 F. (K. and S. method), the percentage of
fixed carbon as reported by different observers varies between 25
and 30 per cent and its solubility in carbon disulfide 97-98 per
cent Near the surface, the rnanjak is hard and brittle with a high
fusing-point, but at the lower levels of the mines it is found softer,
and with a much lower fusing-point, partaking of the nature of an
asphalt, rather than an asphaltite, and clearly proving the meta-
morphosis of one from the other. It also indicates that the manjak
originated in the lower strata, having been thrust upward in the
form of a dyke (see also Trinidad grahamite).

It is used largely for the manufacture of varnishes and japans on
account of its high purity, gloss, and intense black color. 10

Santo Domingo (Haiti). A deposit of glance pitch similar to
the preceding has been reported near Azua on the Bay of Ocoa.
This has not been developed commercially, nor are analyses avail-
able.

CUBA

There are numerous deposits of glance pitch occurring through-
out Cuba, including the following :

Province of Pinar del Rio. Several mines, under the names
"Constancia," "San Jose," etc., occur in the district of Mariel, near
the village of Banes, on both sides of the Alfene River, testing as
follows :

(Test i) Color in mass Black

(Test 4) Fracture Conchoidal

(Test 5) Lustre Dull

(Test 6) Streak Brownish black

(Test 7) Specific gravity at 77 F i . 29-1 .34

(Test 90) Hardness, Moh's scale 2-3

(Test 19) Fixed carbon 24.3-27. 8 per cent

(Test 21 ) Soluble in carbon disulfide 70-74 per cent

Non-mineral matter insoluble 2-3 per cent

Mineral matter 24-27 per cent

(Test 23) Soluble in 88 petroleum naphtha 37. 5-49. o per cent

This glance pitch carries considerable adventitious mineral mat-
ter, thus differing from the preceding.

Province of Santa Clara. Veins of glance pitch have been re-
ported in the northern portion of Sancti Spiritus district, likewise
in Yaguajay district along the eastern bank of River Jatibonico del
Norte. The latter are probably a continuation of the veins occurring
on the west side of this same river in Province of Camaguey, de-
scribed below.

GLANCE PITCH

239

Province of Camaguey. In the Moron district, on the west side
of River Jatibonico del Norte, several mines of glance pitch resem-
bling gilsonite have been developed, known as "Esperanza," u San
Rafael/' "Manocal" and "Talaren." The last named is the
largest, and the product is shipped from Port Tariffa. The material
tests as follows:

Selects

Seconds

(Test
(Test
(Test
(Test
(Test

I)
4)
5)
6)
7)

Color in mass
Fracture
Lustre
Streak
Specific gravity at 77 F

Black
Conchoidal
Bright

Black

1. 12

Black
Conchoidal
Bright
Black

1. 12

(Test

8*)

Hardness, Moh's scale

(Test

15*)

Fusing-point (K. and S. method)

315

345

(Test

15*)

Fusing-point (R. and B. method)

284

372

(Test

19)

Fixed carbon

26 per cent

28 per cent

(Test

)

Soluble in carbon disulfide

99-

25 per cent

97-

per

cent

Non-mineral matter insoluble

23 per cent

per cent

Mineral matter

52 per cent

per

cent

(Test

22)

Carbenes

i per cent

per

cent

(Test

23)

Soluble in 88 petroleum naphtha. . . .

18.

o per cent

per

cent

(Test

26)

Carbon

79-

7 per cent

. . .

(Test

27)

Hydrogen

2 per cent

. . .

(Test

28)

Sulfur

4 per cent

. . .

Undetermined (nitrogen and oxygen) .

8 per cent

...

Total 100.0 per cent

MEXICO

State of Vera Cruz.

District of Chapapote. As stated previously, deposits of very
pure asphalt occur in this locality, varying from very soft consist-
ency to a hard and brittle asphaltite, properly classified as "glance
pitch." They show a lustrous and conchoidal fracture, a black
streak, fuse in the neighborhood of 250 F. (K, and S. method),
contain over 20 per cent of fixed carbon, and are more than 99 per
cent soluble in carbon disulfide.

District of Papantla. Glance pitch occurs near the village of
Talaxca, about 6 miles north of Papantla, within 30 miles of the
port of Gutierrez-Zamora on the Tecolutla River, whence it is trans-
ported by lighters to vessels at Tecolutla on the Gulf of Mexico.
The glance pitch fills a fissure in hard conglomerate in a vein 2 to 3
feet wide, running north and south for a length of about 35 kilo-

240 ASPHALTITES X

meters. It has been mined to a depth of 80 feet, and tests as
follows :

(Test i) Color in mass Black

(Test 4) Fracture Conchoidal

(Test 5) Lustre Bright

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i .093-1 . 108

(Test 1 5^) Fusing-point (R. and B. method) 298-317 F.

(Test 19) Fixed carbon 21 . 5-24.0 per cent

(Test 21) Soluble in carbon disulfide 99.76 per cent

Non-mineral matter insoluble

Mineral matter o . 24 per cent

Total 100 .00 per cent

(Test 22) Soluble in carbon tetrachloride , 99 . 72 per cent

(Test 23) Soluble in 88 petroleum naphtha 27-35 per cent

(Test 28) Sulfur 7. 13 per cent

TT , UNITED STATES

Utah.

Emery County. Deposits of glance pitch occur at Temple
mountain, 45 miles southeast of the town of Greenriver on the
eastern flank of San Rafael swell, also at Flat Top mountain,
2 1 /2 miles to the southeast Occur as glistening black nodules rang-
ing in size up to 2 J^ in. in diameter in a bed of sandstone con-
glomerate about 60 ft. thick. The asphaltite is characterized by the
fact that it carries uranium and vanadium, which are assumed to
have been incorporated in it during its migration from the under-
lying strata, thereby hardening the asphaltite and "fixing" it in the
present associated rocks. The material contains an average of 1.75
per cent U S O 8 and 4 per cent V 2 O 5 . Specimens taken from the
Cowboy claim (Shinarump conglomerate), designated "A," and
from the lower part of sandstone on the west slope of Temple
mountain, designated "B," analyze as follows:

Specimen" A? Specimtn"B"
Per cent Per cent

Loss on ignition * 49-57 67 . 1 1

Ash soluble in HC1:

Uranium oxide (UsOg) i . 13 2.88

Vanadium oxide (V A) 0.23 1.17

Sulfur 4-98 i -37

Arsenic Trace Trace

Selenium. I............. None None

Ash insoluble in HC1 4^-3 a * 6 <$4

Total - 102*13 99.07

X GLANCE PITCH 241

In many places the asphaltite has completely weathered away/
leaving deposits of the metals and metalloids in the form of uranium
and vanadium hydroxides, uranium vanadate, calcium vanadates
(i.e., red and green varieties), calcium-uranium vanadate, potas-
sium-uranium vanadate, copper-uranium arsenate, etc, 1

CENTRAL AMERICA i 2

NICARAGUA

District of Chontales. A vein of glance pitch has been reported
about 10 miles northeast of Santo Tomas, northeast of the moun-
tain range, about i in. thick, in a fault plane of small displacement,
cutting water-laid volcanic tuffa.

SALVADOR

Department of San Miguel. At the waterfall in Quebrada
Granda, one mile southwest of the "Otuscal 1 Ranch," glance pitch
is present as a fracture filling, associated with calcite and chalcedony.

SOUTH AMERICA
COLOMBIA

Department of Tolima. A large deposit of glance pitch occurs
at Chaparral on the Saldana River, which empties into the Magda-
lena River. The deposit is about 100 miles southwest of Bogota.
It is transported by boats down the Magdalena River to the coast,
whence it is exported. About 2000 tons are shipped annually
having a high fusing-point and over 99 per cent soluble in carbon
disulfide. 13 It is used largely for the manufacture of varnish and
tests as follows:

(Test 4) Fracture Conchoidal

(Test 5) Lustre , . Bright

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i , 12

(Test 8a) Hardness, Moh's scale, a

(Test 8i) Hardness, penetrometer o

(Test 15) Fusing-point (K. and S. method) 275 F.

(Test 19) Fixed carbon , 26,45 per cent

(Test 21) Solubility in carbon disulfide 96,0 per cent

Non-mineral matter insoluble o.>per cent

Mineral matter 3.3 per cent

242 ASPHALTITES X

Department of Bolivar. A similar deposit occurs at Simiti, on
the western bank of the Magdalena River, north of the foregoing
deposit

EUROPE

GERMANY

Bentheim. Deposits of asphaltite, probably of the nature of
glance pitch, are found in the vicinity of Bentheim, These were
first regarded as a coal, and have been worked since 1732. The
material is hard, shows a glossy, conchoidal fracture, a black streak,
specific gravity of 1,07 to 1.09, and 0.53 to 11.24 P^ r cent ash.

ASIA

SYRIA (LEVANT STATES)

Vilayet of Sham (Syria). An extensive series of glance pitch
deposits occur in the vicinity of Hasbaya (see map, Fig. 72) in the
upper Jordan valley, on the western slope of Mount Hermon ( Jebel
esh Sheikh). The principal mine, known as "Suk el Chan" or
"Bir el Hummar" is located on the eastern slope of Jebel ed Dahr,
a hill separating the Jordan River (Nahr Hasbani) and the Nahr
Litani, where a deposit of glance pitch of brownish black color is
found in a vein up to 4 m. thick. It has a brilliant lustre and a
black streak, specific gravity at 60 K of 1.104, contains from a
trace to 5 per cent mineral matter, fuses at 275 F., and yields 27
per cent fixed carbon. An average specimen on analysis shows:
carbon 77,18 per cent, hydrogen 9,07 per cent, sulfur 0,40 per
cent, nitrogen 2.10 per cent, and mineral matter 0.50 per cent.
This deposit is said to have been worked since about 1600 B.C.
Some of the ancient pits are still to be seen, as deep as 60 m.
From 1890 to 1900, about 66,000 tons were mined, and a quantity
exported to the United States for the manufacture of varnishes, for
which it is well suited. . In this same region there is, found an
asphaltic limestone impregnated with an average of 10 per cent
asphalt of comparatively high fusing-point (presumably glance
pitch) associated with petrified fish remains. 15

GRAHAMITE

243

Palestine. The Dead Sea deposits are merely of historical inter-
est, as they constituted one of the principal sources of supply of
asphalt for the ancients. There appear to be large veins of asphalt
at the bottom of the Dead Sea, the water of which is saturated with
salt (25 per cent solution) having a gravity of about 1.21. The
asphalt has a specific gravity at 77 F. of 1.104, an d as masses be-
come detached at the bottom by earthquake shocks or otherwise,
they float to the surface, where they are gathered up by natives. A
section through the Dead Sea showing the veins of asphaltite is
illustrated in Fig. 81. Deposits also occur at Es Sebba (Es Sebbe)

FIG. 8 1. Vertical Section, through Dead Sea Showing Glance Pitch Veins.

and Masada on the west shore, and at Seil-el-Modschib on the east
shore of the Dead Sea. This glance pitch shows a lustrous, con-
choidal fracture, and a black streak. Its fusing-point is 275 F.,
over 99 per cent is soluble in carbon disulfide, and it yields 20 per
cent of fixed carbon. The supply is limited and the material is
used only to a small extent locally. 1

MESOPOTAMIA (IRAQ)

A deposit occurs at Abu Gir on the Euphrates River, west of
Baghdad, containing 86.5 per cent soluble in carbon disulfide, 10.0
per cent mineral matter and 3.5 per cent water; having a fusing-
point (R. and B.) of 172 C. and containing 7.3 per cent sulfur.
The mineral constitutents contain Ca, Mg and Fe, with a trace of
vanadium.

GRAHAMITE

This asphaltite varies considerably in composition and physical
properties, some deposits occurring fairly pure and others are asso-

244 ASPHAJLTITES X

dated with considerable mineral matter, running as high as 50
per cent 17 In general, however, it complies with the following :

Test i) Color in mass Black

(Test 4) Fracture Conchoidal to hackly

(Test 5) Lustre Very bright to dull

(Test 6) Streak on porcelain Black

(Test 7) Specific gravity at 77 P.:

Pure varieties (containing less than 10 per

cent mineral matter) 1 . 15-1 .20

Impure varieties (containing more than 10

cent mineral matter) 1 . 175-1 .50

(Test 90) Hardness, Moh's scale 2-3

(Test gk) Hardness, needle penetrometer at 77 F o

(Test 9<r) Hardness, consistometer at 77 F Over 150

(Test gel) Susceptibility index > 100

Behavior on heating in flame:
Variety showing a conchoidal fracture and a

black lustre Decrepitates violently

Variety showing a hackly fracture and a

fairly bright to dull lustre Softens, splits and burns

(Test 150) Fusing-point (K. and S. method) 350-600 F.

(Test 1 5$) Fusing-point (R.. and B. method) 370-625 F.

(Test 1 6) Volatile at 500 F., 5 hrs Less than i per cent

(Test 19) Fixed carbon 30~55 per cent

(Test 21) Soluble in carbon disulfide 45-100 per cent

Non-mineral matter insoluble in carbon disul-
fide Less than 5 per cent

Mineral matter Variable (up to 50) per cent

(Test aa) Carbenes , 0-80 per cent

(Test 23) Soluble in 88 petroleum naphtha Trace-5o per cent

(Test 30) Oxygen in non-mineral matter o-a per cent

(Test 33) Solid paraffins o-Trace per cent

(Test 34^) Sulfonation residue 80-95 per cent

(Test 37*) Saponifiable matter Trace

(Test 39) Diazo reaction No

(Test 40) Anthraquinone reaction , , . . . No

In general, grahamite is characterized by the following features :
i) High specific gravity;

Black streak;

High f us ing-point;

High percentage of fixed carbon,

Solubility of non-mineral matter in carbon disulfide.

A process has been proposed for reducing the fusing-point of
grahamite, by heating the material either alone, or with a propor-
tion of serni-asphaltic residual oil (12 to 14 Baurne) in a closed
retort at 400 F, for twenty- four hours, under a pressure of 50 Ib.
per sq. in. This converts the asphaltite into a product similar in

GRAHAMITE

245

appearance to gilsonite, having a black streak. The percentage of
carbenes is reduced and the proportion soluble in 88 petroleum
naphtha is increased. 18 Processes have been described for fluxing
grahamite with coal tar 19 ; also for fluxing grahamite and adding
a mineral filler. 20

Deposits of grahamite occur in the following localities:

NORTH AMERICA

UNITED STATES

West Virginia.

Ritchie County. The original deposit of grahamite was dis-
covered in West Virginia. 21 It was first described by Prof. J. P.

FIG. 82. View of Grahamite Vein, Ritchie County, West Virginia.

246

ASPHALTITES

Leslie in a paper read before the American Philosophical Society,
March 20, 1863. It is found in but a single locality in Ritchie
County, about 25 miles southeast of Parkersburg. The grahamite
fills an almost vertical fissure in sandstone, a mile long, varying in
width from 2 in. at the ends to 4 and 5 ft. in the center. Its depth
is assumed to be 1500 to 1600 ft

The mine has long been abandoned, as the available supply of
grahamite is exhausted. Figure 82 shows a view of the opening in

FtiULTZQNE^

M/necf from /ot//f

<\ ,VV\ U!DDERM1Y_

' ' - ._ ;#/W

to the Ritchie

rflfrfrr ,^,-0

Elevation

bewhtre

A*WA 16'Wide

f Fissure above fault
I ?4"W/& 30'M& 3&W&

* fissure be fort Faufr

Plan

FIG. 83. Sections through Grahamite Mine, Ritchie County, W. Va.

the hillside from which the grahamite has been removed. Figure 83
shows the nature and extent of the workings. Next to the sand-
stone walls, the grahamite shows a coarsely granular structure, with
a semi-dull fracture. The following layer is highly columnar in
structure with a lustrous fracture. Finally, in the center of the
vein, the grahamite is more compact and massive, with the col-
umnar structure less developed and a semi-dull fracture. This
variation in structure, fracture and lustre is characteristic of gra-
hamite deposits.

On analysis it tests as follows:

GRAHAMITE

247

(Test 6)
(Test 7)
(Test 90)

(Test 150)
(Test 19)
(Test 21)

Streak on porcelain Black

Specific gravity at 77 F 1 . 18-1 . 185

Hardness on Moh's scale 2

Behavior on heating in flame Softens, burns and splits

Fusing-point (K. and S. method) 520-540 F.

Fixed carbon 42 . 1 5-42 , 48 per cent

Soluble in carbon disulfide . . 97. 61 per cent

Non-mineral matter insoluble 0.17 per cent

Combined mineral matter o. 44 per cent

Free mineral matter 1.71 per cent

Total 99 . 93 per cent

(Test 22) Insoluble in carbon tetrachloride 55- o per cent

(Test 23) Soluble in 88 petroleum naphtha 3.0 percent

(Test 25) Hydroscopic moisture 0.07 per cent

(Test 26) Carbon 86. 56 per cent

(Test 27) Hydrogen 8 . 68 per cent

(Test 28) Sulfur i .79 per cent

Difference 2. 97 per cent

Texas.

Fayette and Webb Counties. Clifford Richardson 22 reports a
deposit of grahamite in Fayette County in the neighborhood of
Lagrange, also an occurrence in Webb County, near Laredo, in the
southern portion of the State. These test as follows:

Fayette County
Grahamite,
Per Cent.

Webb County
Grahamite,
Per Cent.

(Test 10)

Fixed carbon

37.7

52.8

(Test 21 )

Mineral matter

4.2

2.O

(Test 2c)

Moisture.

o. 3

O-3

(Test 26)

Carbon

76.2

78.6

(Test 27)

Hydrogen

6.6

7.5

(Test 28)

Sulfur

7.4

5.4

(Test 20)

Nitrogen

0.4

1.2

Undetermined

<.2

C.I

Oklahoma. 23

Pushmataha County. Two small occurrences are reported in
the Potato Hills about 5 miles north of Tuskahoma, One is in SE
y 4 , Sec. i, T 2 N R 19 E, and the other in NE #, Sec. 2, T a
N, R 19 E. Neither of these is of importance.

Jackford Creek Deposit. The largest known grahamite vein in
the world occurs in Jackf ork Valley* 1 2 miles west of Tuskahoma in

ASPHAITITES

the SE J4, NE M, Sec. 9, T 2 N, R 18 E, It is about i mile long,
and varies in thickness from 19 to a maxipium of 25 ft At the
surface, the vein dips at an angle of 37, and after continuing down-
ward for 140 ft, turns suddenly at an angle between 45 and 50 deg.
It is illustrated in Fig. 84. The grahamite fills a fault in shaly sand-
stone. The upper wall of the vein is firm and requires no timbering.
In mining the material, oive-ins are prevented by allowing pillars
of grahamite to remain in place to support the upper "hanging"
rock wall. When the author visited the mine in 1912, a track was
laid along the bottom wall, and the grahamite hoisted out in skips on

Courtesy of Central Commercial Co.
FIG. 84. Vertical Section through Grahamite Mine Near Tuskahoma, Okla.

a cable-way. There is evidence of large pieces of rock having be-
come detached from the hanging wall and fallen into the deposit
of grahamite before it became solid.

As is tfopimon with most grahamite deposits, several distinct
types of material are found in the vein. The grahamite which oc-
curs atong the rock walls for a thickness of 2 to 6 ft. (type b) shows
a hackly (known as a "pencillated") fracture, and a semi-dull to dull
lustre/ whereas the grahamite taken from the center of the vein
(type a) shows a conchoidal fracture and very bright lustre similar
to gilsonite. This is probably due to the fact that the grahamite
in contact with the wall cooled more rapidly than the central portion,

GRAHAMITE

249

and very likely has also been subjected to more or less strain from
movements of the suijounding rock. Many thousand tons of gra-
hamite have been mined from this vein which is now pretty nearly
exhausted (from 6000 to 7000 carloads during the first four years
of its operation, and at the time of the author's visit about 50 tons'
per day). The cost of moving to the surface is comparatively
small, but the material has to be carted 10 miles to Tuskahoma, HI*
nearest shipping point.

On analysis the two varieties (a) and (b) test as follows:

(Test ;) Color in mass (types a and b) Black

(Test 4) Fracture (type a) Conchoidal

Fracture (type b) Hackly

(Test 5) Lustre (type a) .,.., Bright

Lustre (type b) Semi-bright to dull

(Test 6) Streak (types a and b) Black

(Test 7) Specific gravity at 77 F. (types a and b) . . i . 1 8-1 . 195

(Test 9* ) Hardness, Moh's scale 2

Behavior on heating in flame (type a) Intumesces violently

Behavior on heating in flame (type b) Softens, splits and burns

(Test 1 5* ) Fusing-point (K. and S. method) (types a and b) . . 530-604 F,

NOTE. There is no appreciable difference in fusing-point between the two varieties
(a and b)*

(Test 16) Volatile matter 500 F., 5 hrs Less than i per cent

(Test 19) Fixed carbon (types a and b) 52.76-55.00 per cent

(Test 21) Solubility in carbon disulfide Greater than 99. 5 per cent

' Non-mineral matter insoluble Less than o, 5 per cent

Free mineral matter (types a and b) ...,., o. 21-0, 70 per cent

32 77 115

90
80
70
60
50
40
30
20
10

MMM^MBH^ /

tartness
ensile Strength*

1itS*+,fJJ'.f

Fusing Point *2QQF
Susceptibility Index* 2t.$

1^57

45.0

j\k

"**"*-<

"****!

**H

?mt<

755

Si *

2Ear5,
10.0

--.

f*T

'-*

10 ZO W 40 50 eo 70 60 90 100 HO 120 130 140 150 160
Tempera ture,Degrees Fahrenheit

FIG. 85. Chart of Physical Characteristics of Fluxed Oklahoma Grahamite Mixture.

250 ASPHALTITES X

Figure 85 shows the consistometer hardness, tensile strength
(multiplied by 10) and ductility curves of a mixture of the graham-
ite and residual oil, fluxed together so as to have a hardness of
exactly 25.0 at 77 F. (Test gc), equivalent to a penetration at 77
F. of 20 (Test 9&). The mixture contains: grahamite, 60 per cent;
and residual oil, 40 per cent. The resulting fusing-point (K. and S.
method) was 277 F. The same residual oil was used in this test
as for the gilsonite in Fig. 76, and the fusing-point of the grahamite
used was 550 F. (K. and S. method). 24

Another mixture containing 33 per cent of the grahamite and
67 per cent of the same residual oil tested as follows:

(Test 9^) Penetration at 115 F., 50 g., 5 sec 81

Penetration at 77 F., 100 g., 5 sec 50

Penetration at 32 F., zoo g., 60 sec 55

Penetration at o F., 200 g., 60 sec 29

(Test gc) Consistency at 1 15 F 5.8

Consistency at 77 F 11.7

Consistency at 32 F 21 . 5

Consistency at o F 37. 6

(Test 9*0 Susceptibility index 11.7

(Test iob) Ductility at 115 F 15

Ductility at 77 F 3

Ductility at 32 F i J

Ductility at o F , J

(Test 150) Fusing-point (K. and S. method) 135 F.

(Test 15*) Fusing-point (R. and B. method) 147 F.

(Test 16) Volatile at 500 F., 5 hrs o. 6 per cent

(Test 17^) Flash-point 535 F.

This particular mixture is characterized by its extremely low
susceptibility index and its high ductility, which manifests itself
even at o F.

Impson Valley Deposit. This occurs on a branch of the Ten-
mile Creek on the SW J4, Sec. 21 and NW */ 4 , Sec. 28, T i S.,
R 14 E., about 1 6 miles northwest of Antlers. It is known under
various names such as Jumbo Mine, Choctaw Mine, or Old Slope
Mine, This is the second largest deposit in the State of Oklahoma.

It occurs in a zone of faulting and fracture in shale rock, and the
vein is lenticular in form, occurring as a series of pockets of the
general form, illustrated in Fig. 32, varying in thickness from a
fraction of an inch to 30 ft. as a maximum. As the dip of the vein
is very steep, the material must be hoisted out in buckets with a
windlass, and then hauled 15 miles to Moyer, the nearest shipping

X GRAHAM1TE 251

point. Heavy timbering is necessary on account of the character
of the enclosing rock. The grahamite shows the same variation in
fracture and lustre as the Jackford Creek deposit. On analysis it
tests as follows:

Color in mass, fracture, specific gravity, hardness and behavior
on heating in flame, same as the preceding :

(Test 15) Fusing-point (K. and S. method) 460-520 F.

(Test 1 6) Volatile matter, 500 F., 5 hrs Less than I per cent

(Test 19) Fixed carbon 48.5-53-0 per cent

(Test 21) Solubility in carbon disulfide 90. 5-96. a per cent

Non-mineral matter insoluble 0.0-6.0 per cent

Free mineral matter 1 . 1-6. 7 per cent

(Test 22) Carbenes 68 per cent

(Test 23) Solubility in 88 petroleum naphtha 0.2-0.7 per cent

(Test 25) Moisture at ioo-C 0.0-0.7 per cent

(Test 26) Carbon 83.90 per cent

(Test 27) Hydrogen 7.14 per cent

(Test 28) Sulfur i .04-2.24 per cent

Undetermined 6,72 per cent

(Test 340) Saturated hydrocarbons 0.32 per cent

Atoka County. McGee Creek Deposits. Two small veins, one
4 in. and another about i ft in thickness, occur in the SW J4, Sec.
23, T i N, R 14 E, about 15 miles northwest of Antlers. These
constitute the so-called "William's Mine." Shafts have been sunk
from 15 to 20 ft, but not sufficient grahamite has been found to
warrant continuing operations. It tests as follows:

(Test 19) Fixed carbon 43. 5-45.7 per cent

(Test 21) Soluble in carbon disulfide 95-7~99-7 per cent

Non-mineral matter insoluble 0.0-4.0 per cent

Free mineral matter 0.3 per cent

(Test 23) Soluble in 88 petroleum naphtha 4. 5- 6. 8 per cent

A larger deposit also occurs in the vicinity of McGee Creek, in
the NE }4, Sec. 25, T i S, R 13 E, and NW *4, Sec. 30, T i S,
R 14 E, about 12 miles southeast of Stringtown. This is known
as the Pumroy or Moulton Mine. The grahamite fills a fissure,
caused by faulting, and is reported to be 14 to 15 ft. thick at the
surface, tapering to about 4 ft at a depth of no ft. The mine
is now abandoned, but when operated some years ago, about 2000
tons were mined annually, being hauled 1 5 miles to Stringtown, the
nearest shipping point A prospect occurs about % niile south of

252 ASPHALTITES X

the foregoing, consisting of a vein about 2 ft. thick. On analysis
it tests as follows :

(Test 151?) Fusing-point (K. and S. method) 473 F.

(Test 19) Fixed carbon 38.42-41 .o per cent

(Test 21) Solubility in carbon disulfide 83 . 7 -95 . o per cent

Non-mineral matter insoluble 4.8-9,2 per cent

Free mineral matter 0.98- 7.1 per cent

Boggy Creek Deposit. This occurs about 6 miles northeast of
Atoka, and i mile from the M. K. & T. R. R. in the SW %, Sec. 29,
T i S, R 1 2 E. The vein occurs in shale varying in thickness from
several inches to several feet. It has long been abandoned, and no
analyses are available.

Chickasaw Creek Deposit. An undeveloped vein in shale,
carrying streaks of grahamite, about 9 ft. thick has been reported in
Sec, 15, T i S, R 12 E about 2 l / 2 miles east of Stringtown on the
M. K. & T. Railroad.

Stephens County. This occurs in the NW >, Sec. 6, T 2 S,
R 4 W, about 6 miles north of Loco, and 18 miles east of Coman-
che. This vein has been prospected for about half a mile, and occurs
as a fault in sandstone and shale. The vein is of a pronounced len-
ticular type existing in a series of pockets, some as large as 10 ft.
across, often connected with a thin vein-like crack less than an inch
wide. At several points the deposit pinches out entirely. In the
direction of the vein, the pockets measure 25 to 100 ft. horizon-
tally and vertically. A characteristic feature of this deposit is the
infiltration of pyrites, grains of which are clearly visible to the naked
eye. The surrounding shale is porous, and carries minute particles
of the grahamite, which are disseminated throughout the rock for
some distance on both sides of the vein. 25

The material tests as follows:

(Test 4) Fracture Hackly

(Test 5) Lustre Dull

(Test 6) Streak Black

(Test i$a) Fusing-point (K. and S. method) 401-466 F.

(Test 19) Fixed carbon 34.4 -39.4 " pe r cent

(Test ai) Soluble in carbon disulfide 81 . 85-97 . 70 per cent

Non-mineral matter insoluble o . 10- 3 . 60 per cent

Free mineral matter (mostly pyrites) i . 20-14 55 per cent

Colorado.

Grand County. Deposits of grahamite are found in Middle
Park along the continental divide in the northern part of Grand

X GRAHAMITE 253

County. A large vein occurs in Sec. 24, T 4 N, R 77 W, on a fork
of Willow Creek about 25 miles north of Grand River, in a region
of clay, conglomerate and sandstone. Several veins and fissures
have been prospected, the main vein varying in width from 2 in. up
to 6 ft, and extending 100 to 125 ft. Comparatively small quan-
tities of the grahamite have been mined, due to difficulties in trans-
portation to the nearest railroad. The product tests:

(Test 7) Specific gravity at 77 F i , 15-1 > 16

(Test 19) Fixed carbon 47-4 -49-3 per cent

(Test 21) Soluble in carbon disuifide 98 . 2 -99 . 3 per cent

Non-mineral matter insoluble 0.6-1.7 per cent

Free mineral matter o.o - o. i per cent

(Test 22) Carbenes 80.6 per cent

(Test 23) Solubility in 88 petroleum naphtha o. 8 - i .3 per cent

(Test 26) Carbon 85.9 -86. i per cent

(Test 27) Hydrogen 7.63- 7-75 per cent

(Test 28) Sulfur 0.93- 0.99 per cent

Undetermined 5-34- 5-45 per cent

r TT r* MEXICO

State of Vera Cruz.

District of Papantla. Grahamite deposits occur about 20 miles
south of Papantla, near the village of Espinal, forming a continua-
tion of the glance pitch vein at the village of Talaxca (about 6 miles
north of Papantla), previously referred to herein* A total of 5
grahamite veins have been located, with outcroppings at the sur-
face, the widest of which measures 1.5 meters, with an average
length of 700 meters. The asphaltite varies from a true grahamite
(A) to a metamorphized type (B) approaching impsonite, testing
as follows:

Type"A" Type"B"

(Grahamite) (Impsonite)

(Test i) Color in mass Black Black

(Test 4) Fracture Hackly Hackly

(Test 5) Lustre Bright Dull

(Test 6) Streak Black Black

(Test 7) Specific gravity at 77 F 1.15 1.19

(Test 15*) Fusing-point (R. & B.) 375 F. Decomposes

(Test 19) Fixed carbon 37 -o per cent 43-35 per cent

(Test 2i) Soluble in carbon disulfide 99. 80 per cent 20.00 per cent

Non-mineral matter insoluble o. ia per cent 79 .41 per cent

Mineral matter o . 14 per cent o. 59 per cent

Total 100.00 per cent 100.00 per cent

(Test 22) Soluble in carbon tetrachloride 10,3 percent

(Test 23) Soluble in 88 petroleum naphtha . 39 . 7 per cent 3.5 per cent

(Test 28) Sulfur 6. 16 per cent

254 ASPHALTITES X

State of San Luis Potosi.

District of Tamazunchale. A vein of grahamite has been found
at Huasteca on the Panuco River 2e in a vertical fissure, occurring in
shales as an overflow at the junction of the shale stratum with the
overlying sandstone. On analysis the material tests as follows :

(Test 4) Fracture Semi-conchoidal

(Test 5) Lustre Bright

(Test 6) Streak Black

(Test 7) Specific gravity, at 77 F 1.145

(Test 19) Fixed carbon 35.3 per cent

(Test 21) Soluble in carbon disulfide 93 . 8 per cent

Non-mineral matter insoluble 3.4 per cent

Free mineral matter 2.8 per cent

(Test 23) Solubility in 88 petroleum naphtha 8.4 per cent

(Test 26) Carbon 77.67 to 83. 14 per cent

(Test 27) Hydrogen 8 .06 to 8 .09 per cent

(Test 28) Sulfur 7.51 to 5. 47 per cent

State of Tamaulipas. Another deposit has been reported near
the City of Victoria, containing 3.4 per cent of non-mineral matter
insoluble in carbon disulfide and 54 per cent of fixed carbon,

CUBA 27

Province Pinar del Rio. In the District of Mariel, near the City
of Bahia Honda, there occurs a fairly large vein of grahamite,
known as "La America Mine," or the "Rodas Conception Mine/'
testing as follows :

(Test 4) Fracture Shows distinct cleavage veins

(Test 5) Lustre Semi-dull

(Test 7) Specific gravity, at 77 F i . 1 57

(Test 19) Fixed carbon 40.0-42 . 2 per cent

(Test ai) Soluble in carbon disulfide 99.4-99.6 per cent

Non-mineral matter insoluble o.o- o. i per cent

Free mineral matter 0.4- o. 5 per cent

(Test 22) Carbenes About 25 per cent

(Test 23) Solubility in 88 petroleum naphtha.. 17.4-20.0 per cent

A smaller deposit, known as "Santa Julia/' occurs near the
stream of Don Hermanos, 7 miles southwest of Bahia Honda.

Another deposit occurs near the City of Mariel, i mile south
of Mariel Bay, known as the "Magdalena Mine/' which extends
about 100 ft* in length and 40 ft. in width. The first concession was
granted in 1859 involving 3705 acres. The veins consist of a series
.of lenses from 2 to over 30 meters wide, in calcareous rock. The

X GJMHAM1TE 255

deposit has been worked to a depth of about 300 feet Large
quantities of grahamite of a fairly uniform composition have been
mined, characterized by the presence of about 40 per cent of asso-
ciated mineral matter, which has been utilized principally as a com-
ponent of paving compositions. 28 It tests as follows :

(Test 4) Fracture Conchoidal

(Test 5) Lustre Dull

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i .45 to 1 ,49

(Test 15^) Fusing-point (R. and B. method) 374-400 F.

(Test 16) Volatile at 212 F About 5%

(Test 17^) Flash-point (open cup) 41 5-425 F.

(Test 19) Fixed carbon 30.0-38 .o per cent

(Test 21) Soluble in carbon disulfide 51 -58 per cent

Non-mineral matter insoluble 3 -7 per cent

Free mineral matter 38 -42 per cent

(Test 22) Carbenes i . 5- 6.3 per cent

, (Test 23) Solubility in 88 petroleum naphtha 37 -48 per cent

(Test 26) Carbon 7*-5-77.8 per cent

(Test 27) Hydrogen 8.5- 8 .7 per cent

(Test 28) Sulfur ! 6.9- 7.7 per cent

Difference 6.6-11 .4 per cent

Another vein occurs in this same locality, probably a continuation
of the preceding, known as the "Mercedes Mine," testing similarly.

Province of Havana. In the neighborhood of Campo Florida,
grahamite has been obtained from a mine known as "La Habana,"
which tests :

(Test 4) Fracture Semi-conchoidal

(Test 5) Lustre Dull

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i , 175

(Test 19) Fixed carbon 45.0 per cent

(Test 21) Soluble in carbon disulfide 98 . 9 per cent

Non-mineral matter insoluble o. 7 per cent

Free mineral matter 0.4 per cent

(Test 23) Solubility in 88 petroleum naphtha 6.0 per cent

(Test 26) Carbon 82, 5 per cent

(Test 27) Hydrogen 7- 5 per cent

(Test 28) Sulfur 6.4 per cent

Undetermined 3 . 6 per cent

A similar deposit has been reported about 12 miles east of
Havana and another one, known as the "Casitalidad Mine," situ-
ated about 9-10 miles east of Havana, and 2 miles south of the
coast, in a vein 600-900 ft. long and 1-30 ft thick, testing sub-
stantially the same as the preceding.

256 ASPHALT1TES X

Province of Santa Clara* Nine miles northeast of the City of
Santa Clara near Loma Cruz, there occurs the deposit known as
"Santa Eloisa," in a bed of serpentine. It tests as follows:

(Test 4) Fracture Semi-conchoidal

(Test 5) Lustre Bright

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F 1.29

(Test 19) Fixed carbon 34~35 P<* cent

(Test 21) Soluble in carbon disulfide 7 8 ~79 per cent

Non-mineral matter insoluble i . 8-2 . 2 per cent

Free mineral matter 19-20 per cent

(Test 22) Carbenes 2-3 per cent

(Test 23) Solubility in 88 petroleum naphtha. , 31-33 per cent

Another mine occurs a short distance from Placetas del Sur, in
an irregular vein of lenticular form, occurring in several branches.
This mine is known as the "Esperanza," and the product is charac-
terized by its comparatively low fuslng-point The average ma-
terial as mined tests as follows :

(Test 4) Fracture Hackly

(Test 5) Lustre Moderately bright

(Test 6) Streak Black

(Test 7) Specific gravity, at 77 F 1.22

(Test go) Hardness, Moh's scale 2

In flame Softens, splits and burns

(Test 150) Fusing-point (K. and S. method) 400-433 F.

(Test 19) Fixed carbon 52, 95 per cent

(Test 21) Soluble in carbon disulfide 97 9~98 . 8 per cent

Non-mineral matter insoluble 0.05-0. 92 per cent

Free mineral matter i .15-2.75 per cent

Mineral matter combined with non-mineral
constituents 0,37 per cent

SOUTH AMERICA

TRINIDAD

Two deposits of grahamite 29 occur near San Fernando on the
west coast of the island on the shore of the Gulf of Paria, known as
the Vistabella and Marbella Mines. The grahamite has been mar-
keted under the name of "manjak," presumably taking advantage
bf the popularity of the Barbados glance pitch, although from a
geological standpoint the two minerals are entirely different The
veins occur in soft shale and sandstone, in a region carrying petro-
leum in considerable quantities.

X GRAHAMITE 257

A nufnber of veins of grahamite have been uncovered, the lar-
gest known as the Vistabella mine, which measures 360 ft horizon-
tally and has been mined to a depth of about 250 ft Its thickness
is 1 1 ft, at the outcrop, and increases steadily to 33 ft at a depth
of 200 ft Three distinct types have been found in the vein, viz:

1 I ) An amorphous coaly type which has a hackly fracture, and
usually occurs at the margin of the vein. It is dull in lustre and
exhibits no regular jointings,

(2) A columnar type, of dull lustre, having a columnar jointing
running at right angles to the margins of the vein. The jointing is
often well formed, dividing the material into hexagonal or pentag-
onal prisms.

(3) A lustrous variety identical in appearance to gilsonite and
Barbados glance pitch (manjak). This has a bright lustre, and a
conchoidal fracture, being found in the deeper workings of the mine,
at the center of the vein.

There is no chemical difference in the varieties, although it ap-
pears that at the center of*the vein, at a depth of about 120 ft
the grahamite has a lower fusing-point, closely resembling the Bar-
bados glance pitch, thus serving as a link between the grahamite
and the glance pitch, clearly proving that both are derived by
metamorphosis from a common source.

A stratum of oil-bearing sandstone is known to exist beneath the
grahamite, which appears more than likely to have been derived
from an asphaltic petroleum which intruded under pressure through
a fault in the shale.

The mining of the grahamite is comparatively simple, but the
shafts have to be carefully timbered, and precautions have to be
taken to avoid igniting the gases generated in the workings, as these
are highly explosive. Formerly between 2000 and 2500 tons were
mined per annum.

On analysis it tests as follows:

(Test i) Color in mass Black

(Test 2) Homogeneity 3 distinct types recog-
nizable (see above)

(Test 4) Fracture Types I and 2, hackly;

Type 3 conchoidal.

(Test 5) Lustre Types I and 2 dull;

Type 3 bright

(Test 6) Streak,.... Black

(Test 7) Specific gravity, at 77 F 1.170-1.175

258

ASPHALT1TES

(Test ga) Hardness, Moh's scale 2

(Test 9^) Hardness, penetrometer o

On heating in flame Softens, splits and burns

(Test ija) Fusing-point (K. and S. method) 350-438 F.

NOTE. The material resembling glance pitch obtained from the centre of the vein at
the 2oo-ft. level fused at 280 F. (K. and S. method)*

(Test 15^) Fusing-point (B. and R. method) 370-460 F.

(Test 19) Fixed carbon 31 .5-35.0 per cent

(Test 21) Solubility in carbon disulfide 91 .7-96.0 per cent

Non-mineral matter insoluble 0.9- 1.2 per cent

Free mineral matter 4.0- 6.4, averaging

about 5 . 7 per cent
Mineral matter combined with non-mineral

constituents 1.15 per cent

(Test 22) Carbenes About 40 per cent

(Test 23) Solubility in 88 petroleum naphtha:

At loo-ft. level 12 . 8 per cent

At I40-ft. level 15. 2 per cent

At 200-ft. level 18. 5 per cent

At 2OO-ft. level, softer material in center . 56 . o per cent

(Test 25) Moisture 0.2-1 .o per cent

(Test 26) Carbon 84 .o per cent

(Test 27) Hydrogen 5.7 per cent

(Test 28) Sulfur ! 3-0-3.8 per cent

(Test 29) Nitrogen 2. 2 per cent

Figure 86 shows the hardness, tensile strength (multiplied by
10) and ductility curves of a mixture of the grahamite fusing at
400 F (K, and S. method) and residual oil (the same as utilized
in mixture shown in Fig 85,) fluxed together in such proportions

770 , ,, 5 o

too

90
60
70
60
50

' Hardness

Tensile Strength* 10

<S> Fusing Point 277yf
Susceptibility fndex*/2A

.0 10 > 30 40 50 60 70 60 90 100 110 120 130 140 150 160
Temperature.Oegrees Fahrenheit

FIG. $6. Chart of Physical Characteristics of Fluxed Trinidad Grahamite Mixture.

X GRAHAM1TE 259

that the hardness at 77 F. is exactly 25.0 (Test gc), correspond-
ing to a penetration at 77 F. of 20 (Test gb). The resulting mix-
ture contained grahamite, 32 per cent and residual oil, 68 per cent,
and had a fusing-point of 200 F, (K. and S. method).

The Marbella vein is smaller than the Vistabella, attaining a
thickness of 7 ft. near its center. It is lenticular in form and splits
up into two smaller veins at one end. The grahamite mined from
the Marbella vein has substantially the same characteristics as the
preceding. At the 5o-foot level, 8.8 per cent is soluble in 88
petroleum naphtha (Test 23) ; at the 125-ft. level, 9.6 per cent; and
at the 200- ft. level 12 per cent.

ARGENTINA

Province of Mendoza. Asphaltite (presumably grahamite?)
occurs in several localities, containing up to 0.6 per cent ash carrying
38 per cent vanadium oxide (V 2 O 5 ). 30

Province of Neuquen. An unusual variety of grahamite occurs
on the eastern slope of the Andes Mountains, in the form of a ver-
tical vein about 8 km. long and 2 to 3 m. wide. It must be hauled
to the Great Southern Railroad, whence it may be transported to
the nearest port, Bahia Blanca. An average sample tests as follows :

(Test i) Color in mass Black

(Test 4) Fracture Conchoidal

(Test 5) Lustre Bright

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i . 135

(Test 15^) Fusing-point (K. and S. method) About 625 F.

Behavior on heating in flame Decrepitates violently

(Test 21) Soluble in carbon disulfide 53-35 per cent

Non-mineral matter insoluble 46.40 per cent

Mineral matter o. 25 per cent

Total 100.00 per cent

This asphaltite fluxes with great difficulty with residual oils de-
rived from asphaltic and semi-asphaltic petroleums, which necessi-
tates the mixture being heated to 500 F. for several hours. During
this treatment, the "non-mineral matter insoluble" undergoes depoly-
merization, until it all eventually goes into solution. On the other
hand, it fluxes quite readily with linseed oil on heating to 500 F,
This grahamite is unusual, in that although half is insoluble in

ASPHALTJTES X

carbon disulfide, yet it may be fluxed completely as described. It is
apparently on the border line between true grahamite and impsonite.

PERU
Province of Tarma.

Department of Junin. Deposits of grahamite occur near Huari,
a small town in the Department of Junin, a few miles west of the
southern branch of the Central Railway of Peru, at altitudes of
15,000 to 16,000 ft. in the Andes Mountains. They occur as len-
ticular veins in limestone, and are characterized by the mineral con-

FIG. 87. Map of Grahamite Region in Peru.

stituents carrying vanadium compounds, probably in the form of
sulfide. The region is illustrated in Fig. 87, and includes the fol-
lowing mines: The Chiucho mine consists of a vein 6 in. to 35 ft.
wide, 15 miles from the railway, averaging: moisture 2.35 per cent,
volatiles 40.45 per cent, fixed carbon 55,0 per cent, and ash 2.20
per cent containing i.o to 2.25 per cent vanadic oxide (V a O). La

X GRAHAM1TE 261

Lucha mine is connected with the railroad by a small tramway 5
miles long. The output has been utilized extensively as a fuel by
the neighboring smelters, and contains: moisture 1.15 per cent, fixed
carbon 44.48 per cent, volatiles 48.65 per cent, and ash 5.72 per
cent carrying less than i per cent vanadic oxide. It is assumed that
the vanadium must have been present originally in the asphaltic
petroleum from which the grahamite was derived, since it is not
found in the associated rocks. In substantiation of this hypothesis,
it is pointed out that vanadium is similarly associated (up to i per
cent) with certain black carbonaceous shales in the province of
Jauja, some distance from the foregoing deposits. 31

Other occurrences have been reported at Minasragra, near
Cerro de Pasco, also at Lacsacocha (Yauli), both of which con-
tain vanadium.

CHAPTER XI

ASPHALTIC PYROBITUMENS *

The asphaltic pyrobitumens are natural substances composed
of hydrocarbons, characterized by their infusibility and comparative
freedom from oxygenated substances. They are grouped into five
classes, viz. : elaterite, wurtzilite, albertite, impsonite, and asphaltic
pyrobituminous shales. The first four are comparatively free from
associated mineral matter (usually under 10 per cent). If the min-
eral matter predominates, the material is known as an asphaltic
pyrobituminous shale, which term is applied indiscriminately to
shales containing wurtzilite, albertite or impsonite.

Much confusion exists regarding the classification of asphaltic
pyrobitumens. Every now and then it is alleged that some new
type is discovered, which on closer investigation proves to be an old
substance christened under a different name. Thus the so-called
"nigrite" described by G. H. Eldridge 2 is nothing more than
albertite.

Elaterite, wurtzilite, albertite and impsonite when they occur
associated with less than 10 per cent of mineral matter, are distin-
guished from one another as follows:

Streak

Specific Gravity
at 77 P.

Fixed Carbon,
Per Cent

Elaterite

Light brown

O.QO I .(X

2-<

Wurtzilite

Light brown

I (X I O7

* j
C 2C

Albertite

Brown to black

i 071 10

> *j

2C <O

Impsonite

Black

i. 10-1 .25

*j j w
CO-QO

All four are derived from the metamorphosis of petroleum, and
it is probable that the impsonite represents the final stage of trans-
formation of elaterite, wurtzilite and albertite, as well as the as-
phaltites (gilsonite, glance pitch and grahamite).

262

XI ELATER1TE 263

ELATERITE

This asphaltic pyrobitumen is the prototype of wurtzilite. It is
found in a few localities, in small amounts and is of scientific in-
terest only*

ENGLAND

Derbyshire County. Elaterite was originally discovered at the
Odin Mine in Castleton by M. Lister in i673-4. s It was again
described by C. Hatchett, 4 who found it to be moderately soft and
elastic, like India rubber, having a specific gravity of 0.953 0.9 8.
It is slightly soluble in ether (18 per cent) and swells up in petro-
leum naphtha. H. J. Klaproth 5 examined this same material, stat-
ing that it " fuses at a high heat, and after this may be drawn into
threads between the fingers," also that it contains between 6 and 7
per cent of ash. 6

AUSTRALIA
State of South Australia.

Coorong District. A variety of elaterite is found on the coast
south of Adelaide, Australia, known under the name of "coorong-
ite." 7 It is a rubbery product, known as "Australian caoutchouc, "
which shows: fixed carbon i per cent, volatiles 97 per cent, and ash
2 per cent. It was deposited on the ground after the subsidence of
the floods in 1865 and again in 1920. It is contended that coorong-
ite is derived from algae-like organisms, similar to those which are
still to be found in certain salt lakes in South Australia. These or-
ganisms appear on the lakes in winter and are blown ashore, where
they are supposed to consolidate into coorongite.

ASIATIC RUSSIA

State of Turkestan. A deposit occurs at the mouth of the Hi
River, in the neighborhood of Lake Balkash, 8 and tests as follows :

(Test 7) Specific gravity 0.995

(Test 21) Solubility in carbon disulfide Very slight

Free mineral matter 3-5 per cent

(Test 370) Acid value 4.9

(Test 37^) Saponification value 56 . 9

(Test 37*) Saponifiable matter 1 1 . t per cent

Unsaponifiable matter 88 .9 per cent

It is characterized by the presence of saponifiable matter, and
in this respect differs from the foregoing. A similar deposit occurs

264

ASPHALT1C PYROBITUMENS

along Lake Ala-Kool (Ala-Kul), east of the foregoing, in masses
2-10 ft. wide and up to 2 in. thick, associated with algae. 9

WURTZILITE
This has been found in but one region, 10 as follows :

Utah.

UNITED STATES

Uinta County. This region embraces about 100 square miles in
the neighborhood of Indian, Lake, Avintequin and Sams Canyons,
tributaries of Strawberry Creek, which in turn leads into the Uinta

River. The veins occur about 50 miles
southwest of Fort Duchesne, varying
in length from several hundred feet
to about 3 miles, and from i to 22 in.
wide, filling vertical faults in shaly
limestone. Altogether about 30 veins
have been discovered, closely resem-
bling those of gilsonite. Many of
them split into a number of smaller
branches, either in a vertical or hori-
zontal direction. The largest veins
occur between the Left-Hand and the
Right-Hand forks of Indian Canyon.
Wurtzilite has been exploited under
various names, including elaterite
(improper use of this name), aeger-
ite, aconite, etc.

A view of one of the veins is
shown in Fig. 88; a section through
the mine, in Fig. 89; and the tram-
way for conveying the product from
the hillside mine to the valley below,
in Fig. 90.

Wurtzilite is characterized by being sectile and cutting like horn
or whalebone. Thin flakes are somewhat elastic, comparable in a
way to that of glass or mica, rather than to the yielding elasticity
of rubber. If a shaving is bent too far or suddenly, it snaps off like

Courtesy of Raven Mining Co.

FIG. 88. View of Wurtzrlite
Mine, Uinta County, Utah.

WURTZ1UTE

265

Courtesy of Raven Mining Co.
FIG. 89. Vertical Section through Wurtzilite Vein, Uinta County, Utah.

Courtesy of Kaven Mining Co,
Fia 90. Transporting Wurtzilite from the Mine.

266 ASPHALTIC PYROBITUMENS XI

glass. This distinguishes it from other asphaltic pyrobitumens as
well as the asphaltite^s. Attempts were made to find its fusing-point
by heating it as high as 800 F. in sulfur, but without having any
effect.

It tests as follows :

(Test i) Color in mass Black

(Test 4) Fracture. Conchoidal

(Test 5) Lustre Bright

(Test 6) Streak Light brown

NOTE. Extremely thin splinters are semi-
transparent, showing a deep red col-
or by transmitted light.

(Test 7) Specific gravity at 77 F 1.05-1,07

(Test 90) Hardness, Moh's scale Between 2 and 3

(Test 9^) Hardness at 77 F. (penetrometer) o

(Test 9<r) Hardness at 77 F. (consistometer) Over 150

On heating in flame Softens and burns quietly

(Test 15) Fusing-point Does not fuse without de-
composition

(Test 16) Volatile at 325 F., in 5 hrs i- 3 per cent

(Test 19) Fixed carbon 5-25 per cent

(Test 21 ) Soluble in carbon disulfide 5-10 per cent

Non-mineral matter insoluble 85-95 per cent

Mineral matter 0.2-2,5 per cent

(Test 22) Carbenes o.o-i . 5 per cent

(Test 23) Soluble in 88 petroleum naphtha 0-2 per cent

(Test 26) Carbon 79. 5-80.0 per cent

(Test 27) Hydrogen 10. 5-12. 5 per cent

(Test 28) Sulfur 4.0-6.0 per cent

(Test 29) Nitrogen 1 . 8-2. 2 per cent

ALBERTITE

Albertite is a generic term applied to a group of asphaltic pyro-
bitumens similar to the type-substance which was formerly mined
in Albert County, New Brunswick, Canada. The name "carboids"
has also been suggested for this group of substances, 11 and the terms
"kerotenes" and "kerites" to designate broadly those hydrocarbons
that are insoluble in carbon disulfide. Albertites are characterized
by their

} Infusibility;
2 ; Insolubility in carbon disulfide, etc. ;

3) Specific gravity (1.07 to i.io at 77 F.) ;

4) Percentage of fixed carbon (25 to 50 per cent) ;

5) Small percentage of oxygen present in the non-numeral
constituents (less than 3 per cent).

It occurs in several localities, of which the typical deposit will
be described first.

XI ALBERTITE 267

CANADA
Province of New Brunswick.

Albert County. In 1849 * local geologist, Dr. Abraham Ges-
ner, discovered a substance originally termed "albert coal," subse-
quently renamed "albertite," 12 on Frederick Brook, a branch of
Weldon Creek, near Albert Mines, 20 miles south of Moncton.
Shortly after this, litigation gave rise to a discussion whether or
not the mineral was a true coal. The courts decided that it was,
and not until many years later was its true status determined.

The principal vein has been traced approximately 2800 ft. and
varies in thickness from several inches to a maximum of 17 ft. It is
connected with a number of smaller lateral veins which in turn break
up into still smaller offshoots. The maximum depth reached by
mining operations was approximately 1400 ft, and it is estimated
that altogether 230,000 tons have been mined. The main use of
the product was to enrich bituminous coal in the manufacture of
illuminating gas, but it is no longer available, as the mine has been
inactive for many years.

This occurrence takes the form of a true fissure vein cutting
across a series of beds of so-called u oil shales," which will be de-
scribed in greater detail later. Mention should be made here that
the surrounding shales abound in fossil remains of fish, which indi-
cate that albertite and its associated shales are of animal origin.

On analysis it tests as follows:

(Test i) Color in mass Black

(Test 2) Homogeneity Uniform

(Test 4) Fracture Conchoidal to hackly

(Test 5) Lustre Bright

(Test 6) Streak Brown to black

(Test 7) Specific gravity at 77 F 1.075-1.091

(Test 90) Hardness, Moh's scale 2

(Test 9^) Hardness, penetrometer, 77 F o

(Test gc) Hardness, consistometer, 77 F Greater than 150

On heating in flame Intumesces

(Test 15) Fusing-point Infusible. Decomposes

before it melts

(Test 19) Fixed carbon 25 -50 per cent

(Test 21) Soluble in carbon disulfide 2 -10 per cent

Non-mineral matter insoluble 85 -98 per cent

Mineral matter o. 1-0.2 per cent

(Test 23) Soluble in 88 petroleum naphtha o. 5-2,0 per cent

(Test 24) Solubility in pyridine (boiling) 25-35 per cent

268

ASPHALTIC PYROBITVMENS

(Test 26)

Carbon

/
Per
Cent

8^.44.

Per
Cent

8< 4.O

///

Per
Cent
8c <t

P<r
Cent

86 31

Per

Cent

87 2C

(Test 27)

Hydrogen. ..........

10 08

92o

j jj
11 20

8 96

96*1

(Test 28)

Sulfur

. *w

Trace

i 20

Trace

. u,*

(Test 29)

Nitrogen

l.IO

O 42

2 GO

I 7C

(Test 30)

Oxygen

j. AW

2.22

^ *!"*

* 7 W
I O7

* / J

Undetermined

6 . o A.

O 12

O IO

I 21

IOQ.OO 100.04 IO -35 100.24 99.83

Province of Nova Scotia.

Pictou County. An unusual deposit occurs immediately below
the well-known McGregor seam at Stellarton. The approximate
thickness of the bed is given as 5 ft, subdivided as follows:

j I } A layer of coal I ft. 4 in, wide.
2) A layer of albertite i ft 10 in, wide.
(3) A layer of pyrobituminous shale i ft 10 in. wide.

This species of albertite has been exploited under the name
"stellarite." It seems to represent a state of transition between
true albertite and the cannel coals, of which the Scotch mineral
torbanite is a representative. The bed contains fossil animal and
vegetable remains. A splinter of stellarite may be easily lighted
with a match and will burn with a bright, smoky flame, throwing off
sparks like stars (whence its name) . It was formerly used to enrich
bituminous coal in the manufacture of illuminating gas. The layer
of coal is an ordinary fat-coking coal, showing a laminated struc-
ture, and containing 62.09 P er ce ^t of fixed carbon and 4.33 per
cent of ash.

The stellarite and associated pyrobituminous shale tests as
follows :

Stellarite
(Albertite)

(Test i) Color in mass Brown to black

(Test 4) Fracture Hackly

(Test 5) Lustre Semi-bright to dull

(Test 6) Streak Reddish brown

(Test 7) Specific gravity at 77 F, . 1.07-1.10

(Test 15) Fusing-point Infusible

(Test 19) Fixed carbon. 22.35-25. 23 per cent

(Test ai) Soluble in carbon disulfide 2,0 per cent

* Mineral matter 8 . 2-8 . 9 per cent

(Test aj) Moisture.. 0.2-0.3 per cent

(Test 26) Carbon 88.1 per cent

(Test 27) Hydrogen, n . i per cent

(Test 28) Sulfur o. i per Cent

(Test 29) Nitrogen 0.2 per cent

(Test 30) Oxygen o.j per cent

Pyrobituminou*
Shale

Gray black
Conchoidal
Dull
Brown
1,56-1.78
Infusible

8.3-12.3 percent
Trace

52,0 -62.0 per cent
0.6 - i.oper cent

0.25- 0.74 per cent

XI ALBERTITE 269

The presence of the very small percentage of oxygen (0.5 per
cent) differentiates the material from lignite and the other non-
asphaltic pyrobitumens, thus corresponding with the ultimate analy-
sis of the New Brunswick albertite.

UNITED STATES
Utah.

Uinta County. A vein of albertite (christened "nigrite" by
Eldridge), 120 ft long, showing a maximum width of 20 in., is
found 8 miles from Helper, and 5 miles east of Soldier Summit,
having the following characteristics :

(Test 4) Fracture Conchoidal

(Test 5) Lustre Semi-dull

(Test 6) Streak Brownish black to black

(Test 7) Specific gravity at 77 F 1.091-1.099

(Test 90) Hardness, Moh's scale 2

Behavior on heating in flame Splits and burns

(Test 15) Fusingrpoint Infusible

(Test 19) Fixed carbon 37~4Q per cent

(Test 21) Soluble in carbon disulfide 3- 6 per cent

Non-mineral matter insoluble 94- 2 ~"97- P er cent

Mineral matter o. 2 per cent

(Test 23) Soluble in 88 petroleum naphtha Trace

(Test 28) Sulfur i .o per cent

SOUTH AMERICA
Falkland Islands.

An asphaltite resembling albertite, having a specific gravity at
77 F. of 1.04, containing 3.7 per cent of siliceous ash, and mostly
insoluble in the usual solvents, has been reported. 18

GERMANY

Province of Hanover. A small deposit of albertite-like pyro-
bitumen was discovered in 1870 south of the village of Bentheim,
east of the city of Giidehaus. The material was mined years ago
and utilized as fuel, under the name "Gagat-kohle." It occurs in a
fault of a deposit of clayey schist, in a vein 0.50 to 0.65 m. wide.
The material has a high lustre, a conchoidal fracture, a black streak,
specific gravity at 77 F. 1.075, hardness 2.5, soluble in carbon
disulfide 23.5 per cent, slightly soluble ip turpentine, ash 0.53 per
cent. It softens and swells in a flame and distills without fusing.
The mine is now idle, 14

270 ASPHALT1C PYRQB1TUMENS XI

AUSTRALIA

Tasmania. A species of albertite described under the name of
"tasmanite" 16 has been reported near the River Mersey in the
northern portion of Tasmania. It is found disseminated in pyro-
bituminous shale and complies with the following tests :

(Test l) Color in mass Black

(Test 2) Homogeneity Uniform

(Test 4) Fracture Conchoidal

(Test 5) Lustre Bright

(Test 6) Streak Yellowish brown

(Test 7) Specific gravity at 77 F i . 10

(Test go) Hardness, Moh's scale 2

(Test 15) Fusing-point Infusible

(Test 21) Soluble in carbon disuifide Trace

Mineral matter 8-14 per cent

(Test 26) Carbon 79-^ "79-3 per cent

(Test 27) Hydrogen 7.2 - 7.4 per cent

(Test 28) Sulfur 5.28- 5.32 per cent

(Tests 29 and 30) Nitrogen and oxygen 4. 93 per cent

PORTUGUESE WEST AFRICA

Province of Angola.

District of Libollo. A species of albertite is reported at Calu-
cala, 14 miles north of the railway station Zenza .do Itombe (which
is 1 8 miles east of Luanda on the Luanda-Malange Railway line)
under the name "libollite." 16

IMPSONITE

This represents the final stage in the metamorphosis of asphal-
tites and asphaltic pyrobitumens. It is characterized by its :

1 i ) Infusibility and insolubility in carbon disuifide ;

(2) Specific gravity (i.io to 1.25) ;

(3) High percentage of fixed carbon (50 to 85 per cent) ;

(4) Comparatively small percentage of oxygen (less than 5 per
cent) t which differentiates it from the non-asphaltic pyrobitumens.

The weathered asphaltites taken from the exposed portions of
the vein, where they have been subjected for centuries to the action

XI IMPSONITE 271

of the elements, closely resemble impsonite in their physical and
chemical properties, and may therefore be classified as such. Out-
crops of grahamite are especially prone to metamorphize into imp-
sonite, and many prospectors have been misled on this account
The following represent the most important deposits :

, IT

NORTH AMERICA

UNITED STATES
Oklahoma.

La Flore County. One of the largest deposits of impsonite oc-
curs 2 miles east of Page on the southern slope of Black Fork
Mountain (S J4, Sec 24, T 3 N, R 26 E), filling a fissure caused
by a fault. The vein is about 10 ft thick, and has been mined to
some depth. It complies with the following tests:

(Test i) Color in mass Black

(Test 4) Fracture Hackly

(Test 5) Lustre Semi-dull

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i . 235

(Test 9*) Hardness, Moh's scale 2-3

Heating in flame Decrepitates

(Test 15) Fusing-point Infusible

(Test 19) Fixed carbon 75.0-81 .6 per cent

(Test 21) Soluble in carbon disulfide 4- 6 per cent

Non-mineral matter insoluble 93-96 per cent

Mineral matter o . 7-2 , 5 per cent

(Test 24) Solubility in pyridine (boiling) 3. 88 per cent

(Test 25) Moisture o. i-i . 5 per cent

(Test 28) Sulfur i ,69 per cent

Murray County. Impsonite has been reported 5 miles north-
east of Dougherty (Sec. 33, T i S, R 3 E), in a vein about 18 in.
thick at the top and 7 ft. at the bottom. Its characteristics are
similar to the preceding.

Arkansas.

Scott County. Another deposit of impsonite, referred to as
"arkosite," 18 occurs in the western part of Fourche Mountain,
about 1 2 miles east of the Black Fork Mountain locality in Okla-
homa. The exact locality is I mile east of Eagle Gap, and 2 miles

272 ASPHALT1C PYROBITVMENS XI

st of Harris, It occurs in a region of shale and sandstone, and
tests as follows:

; (Test i> Color in mass Black

(Test 4) Fracture Hackly

(Test 5) Lustre Semi-dull

(Test 6) Stfeak Black

(Test 7) Specific gravity at 77 F i .25

(Test 94) Hardness, Moh's scale 3

Heating in flame Decrepitates

(Test 15) Fusing-point Infusible

(Test 19) Fixed carbon 80, o per cent

(Test ai) Soluble in carbon disulfide Trace

Non-mineral matter insoluble 99. 3 per cent

Mineral matter 0.6 per cent

(Test 28) Sulfur 1.38 per cent

Nevada.

Eureka County. A deposit is reported 15 miles south of Pali-
sade in Pine Creek valley, in a vein filling a fault about 300 ft. long
and of unknown depth. Its physical and chemical characteristics
are similar to the preceding. 1

, 19

Michigan.

Keweenaw County. An interesting formation has been de-
scribed in the vicinity of the Porcupine Mountains in the southwest
part of Keweenaw Point, in which the impsonite acts as a cement in
sandstone beds carrying grains of native copper. Much of the imp-
sonite is surrounded by copper, giving rise to the assumption that
the former was present prior to the deposition of the copper. The
impsonite analyzes: 64.8 per cent fixed carbon and 33.3 per cent
ash containing 2 per cent copper. 2

, 20

SOUTH AMERICA
PERU 21

Canta (Department of Lima) and Yauli (Depart-
ment of Junin). More than a do^en veins have been found in the
District of Yantac, about 28 miles from CasapiUica, on the Central
Railway of Peru, near the city o } f Marcapomacocha (see Fig. 87),
also at Cajatambo (Cojcitambo), having a specific gravity qf 1.25, a

XI IMPSONIT& 273

bright conchoidal fracture, a black streak and 1,6 per cent ash, 82
They occur along both slopes of the western Cordillera of the
Andes, at altitudes of 12,000 to 16,000 ft, and vary in thickness
from a few inches to 5 ft. The average composition shows : mois-
ture 5.2 per cent, fixed carbon 72.2 per cent, volatile 10.3 per cent,
and ash 12.3 per cent (containing 5 to 16 per cent of vanadic oxides
V 2 O 5 ). The presence of tiny fissures radiating from the main vein,
and the inclusion of "horses" in the vein proper differentiate the
material from a coal formation. It is, however, distinctly anthra-
cite in character, burning with little to no flame.

Llacsacocha Mine occurs 13 miles by trail south of the town of
Yauli, extending for more than 1200 ft. in limestone formation,
having numerous lenses and faults. It is black and lustrous, free
from pyrites, and contains: fixed carbon 88.2 per cent, volatile 9.0
per cent, and ash 2.8 per cent (carrying 15 per cent vanadic oxide).

Rumichaca Mine at Minasragra, near Cerro de Pasco, yields
about 80 per cent of the world's supply of vanadium and is the
largest of all in the Yauli district. Being close to the railroad, it
has been largely worked during the past ten years, and used as a
fuel. The vein carries from a few inches to 40 ft in width and
contains an average of 16 per cent ash (carrying 5.3 per cent vana-
dic oxide) otherwise it is similar in composition to the foregoing.

Negrita Mine is situated 15 miles from the railroad, near Hulla-
cocha Lake, occurring as a true fissure vein, cutting across limestone
and shale. Three lenses yielded 2000 tons. An average analysis
showed 9.5 per cent ash (carrying 5 per cent vanadic oxide).

Cacharata Mine is located about 1000 yd. from the previous
vein and measures 2 ft. wide, being similar in composition.

Province of Huarochiri (Department of Lima). Narrow and
irregular veins occur at Sillapata, 15 miles from the railway station
of Matucana, running high in ash (averaging slightly less than i per
cent of vanadic oxide).

BRAZIL

State of Sao Paulo. Irnpsonite has been found in a dyke near
Limeira, analyzing: fixed carbon 76 per cent, volatile matter 5 per
cent, and ash 1 6 per cent/

.83

274 ASPHALTIC PYROB1TVMENS XI

AUSTRALIA

West Australia. A deposit of impsonite has been reported in
West Australia having a specific gravity of 1.154, moisture 0.37
per cent, fixed carbon 56.27 per cent, volatiles 41.91 per cent, and
ash 1.82. It does not melt up to 300 C* 4

CHAPTER XII
PYROBITUMINOUS SHALES 1

Under this heading will be considered the oil-forming shales
containing pyrobitumens associated with earthy matter, which will
produce oily or tarry distillates upon being subjected to destructive
distillation. Oil-bearing and asphalt-bearing shales from which pe-
troleum or asphalts may be extracted w r ith solvents are not included.
The well-known shales in France occurring at Autun (Saone-et-
Loire) and Bruxieres-les-Mines (Allier) consisting of semi-liquid
asphalt associated with shales shall accordingly be excluded, al-
though these have been classified indiscriminately with the true pyro-
bituminous shales by other writers.

Pyrobituminous shales may be sub-divided into two classes :

1 i ) Asphaltic pyrobituminous shales in which asphaltic pyro-
bitumens (elaterite, w T urtzilite, albertite or impsonite) are associated
with shales.

(2 ) Non-asphaltic pyrobituminous shales in which non-asphaltic
pyrobitumens (cannel coal, lignite or bituminous coal) are associated
with shales.

Little or no attempt has been made to differentiate between
these two groups, on account of the difficulty in identifying the
bituminous material present. This will become apparent when it is
considered that pyrobitumens are more or less insoluble in solvents
and are moreover masked by the associated mineral matter, which
interferes with the usual distinguishing tests, such as the specific
gravity, lustre, streak, etc. Up to the present time all pyrobitu-
minous shales have been referred to under the general term "oil
shales," which is really a misnomer.

The following means are suggested to differentiate the two
classes:

( i ) By the pyrobitumens found locally.

The presence of asphaltic bitumens in the vicinity would indicate
an asphaltic pyrobituminous shale. Similarly, non-asphaltic pyro-

275

276

PYROBITUMINOUS SHALES

XII

bitumens would tend to establish the identity of the shale as non-
asphaltic. If both types are present, the eviaence is non-conclusive.

(2) By the associated fossil remains.

If vegetable (plant) fossil remains only are found associated
with the shale, the indications are that it is non-asphaltic, since it
is definitely established that the non-asphaltic pyrobitumens are of
vegetable origin. On the other hand, if animal (fish or mollusc)
fossil remains are present, the shale will more, than likely represent
the Asphaltic pyrobituminous variety,

(i) Effect of heat on the solubility.

On heating in a closed retort to 300 to 400 C, asphaltic pyro-
bituminous shales will depolymerize and become more soluble in
carbon disulfide, whereas the non-asphaltic pyrobituminous shales
remain unaffected. It is also interesting to note that the bituminous
constituents of non-asphaltic pyrobituminous shales are rendered
fusible and soluble by neating the finely powdered shale to 500 to
600 F. in a closed retort with a residual oil derived from petro-
leum, or with coal tar. 8

(4) By the percentages of fixed carbon and oxygen (calculated
on the basis of the non-mineral matter present). These two cri-
teria, considered together, furnish the most reliable means of dis-
tinguishing between the two classes of shale, as will be observed
from the following figures, calculated on the basis of the non-min-
eral constituents present :

Fixed Carbon
(Calculated on the
Ash-free Basis)
Per Cent

Oxygen (Calculated
on the Ash-free Basis)
Per Cent

Asphaltic Pyrobituminous Shaks;
Wurtzilite shalefc

i IO

Less than 2.

Albert! te shales. ,

c <5i?

Non*asphaUie Pyrobituminous Shaks:
Cannel coal shales

5^*5

'irt

Less than 3

Lignite shales

5 -*

1 C 1ft

5-10

**- - ** Q

Bituminous coal shales

*J J u

iCCO

15 25

ff T O

x j y->

3*s

It will be noted that the percentage of fixed carbon calculated on
the mineral-free basis, runs Ipwer than in the corresponding (pure)
pyrobitumens, due to the presence of the mineral matter, which
assists in the combustion of the xarbon during the test, decreasing
the yield of "fixed carbon," and at the same time increasing the
percentage of volatile constituents. This is important from * com-

XII PYROBITUMINOUS SHALES 277

mercial viewpoint The most valuable pyrobituminous shales are
those which produce the largest amount of volatile matter when
subjected to destructive distillation. This is true with the albertitic,
cannel coal (torbanitic) and lignitic shales, whereas the bituminous
coal shales yield but little volatile matter and have no commercial
importance.

Two types of bituminous constituents are present in non-
asphaltic pyrobituminous shales, viz.: (i) macerated and carbon-
ized plant remains similar to coal, and (2) yellow resinous bodies
representing the last stage in the oxidation of the woody tissue,
Elaterite, wurtzilite and impsonite shales are rarely found.

Pyrobituminous shales generally contain more than 33 per cent
of associated mineral constituents. The non-mineral constituents
present in non-asphaltic pyrobituminous shales have been designated
by the terms "kerogen" s or "petrologen." *

From the foregoing it will be apparent that the subject of "pyro-
bituminous shales" is an extremely complicated one, still requiring
a vast amount of research work before all the deposits can be cor-
rectly classified.

Pyrobituminous shales are treated exclusively by subjecting
them to a process of destructive distillation in suitable retorts to
recover the tarry distillate and ammonium sulfate as will be de-
scribed in Chapter XVI. The intrinsic value of the shale is de-
pendent upon the amount of shale tar and ammonium sulfate
obtained.

A detailed description of the individual deposits of pyrobitumi-
nous shales does not fall within the scope of this publication.

PART III
TARS, PITCHES, AND PYROGENOUS ASPHALTS

CHAPTER XIII
GENERAL METHODS OF PRODUCING TARS

Tars constitute the volatile oily decomposition products ob-
tained in the pyrogenous treatment of bituminous and other organic
substances. The pyrogenous treatment embraces three processes,
viz. :

1 i ) Subjecting to heat alone without access of air, often termed
"destructive distillation," and sometimes referred to as "pyrolysis."

(2) Partial combustion, which may take place either in an at-
mosphere of air and steam (in gas producers) or with a limited
access of air.

(3) Cracking oil vapors at high temperatures.

Practically all organic substances which undergo decomposition
produce tars upon being subjected to heat, provided they yield a
substantial proportion of volatile decomposition products, the tem-
perature is sufficiently high to bring about the decomposition, and
air is entirely or partially excluded during the pyrogenous treat-
ment If the organic substance does not contain volatile matter, as
proves the case with anthracite coal or graphite, no tar will result.
If air is present in too large a quantity, the products of decomposi-
tion will undergo complete combustion, and the tar will be con-
sumed. Materials which evaporate (i. e. } distil undecomposed), or
sublime, will remain unchanged in composition, and products which
explode are converted into permanent gases, without the formation
of tars.

At the present time tars are produced commercially from the
following products :

278

XIII

GENERAL METHODS OF PRODUCING TARS

279

(1) Bituminous substances including peat, lignite, bituminous
coal, petroleum and pyrobituminous shales.

(2) Certain other organic substances including wood, and
bones.

The following will give a synoptical outline of the raw materials
used, the modes of treatment and the kinds of tar produced:

Raw Materials Used

Heat Alone
(" Destructive
Distillation")

Partial Combustion

"Cracking"

Air and Steam
("Producers")

Limited Access
of Air

Bituminous substances:
Petroleum products. . . .
Peat

Wax tailings

Peat tar
Lignite tar
Shale tar
Gas-works coal
tar
Coke-oven coal
tar

Wood tar
Bone tar

[Pressure tar
I Oil-gas tar
I Water-gas tar

Peat tar

Lignite tar
Shale tar

Producer-gas
coal tar

Lignite

Pyrobituminous shales.
Bituminous coals

Other Organic Materials:
Wood

Blast furnace
coal tar

Bones

Petroleum products (e.g., "gas oils") upon being subjected to a
high temperature under more or less pressure in a closed retort will
result in the formation of oil-gas tar; and when sprayed on incan-
descent anthracite coal or coke result in the production of water-gas
tar. Peat, lignite and pyrobituminous shales result in the formation
of peat-, lignite- and shale-tars respectively: (i) when subjected to
destructive distillation, or (2) upon undergoing partial combustion
in an atmosphere of air and steam in a so-called "gas producer."
Tars resulting from these two processes are similar in composition
and hence are designated by the same name. Destructive distilla-
tion yields a larger percentage of tar than partial combustion in an
atmosphere of air and steam.

Bituminous coals form different kinds of tar, depending upon
the nature of the process. Thus gas-works coal tar and coke-oven
coal tar are produced by the destructive distillation of bituminous
coal in gas-works retorts and coke-ovens respectively. Producer-gas

280 GENERAL METHODS OF PRODUCING TARS XIII

coal tar is derived from the partial combustion of bituminous coal
in an atmosphere of air and steam in a gas producer. Blast-furnace
coal tar results from the partial combustion of bituminous coal in a
limited access of air in a so-called "blast furnace," Destructive
distillation of wood results in the formation of wood tar, and of
bones in the production of bone tar.

In the order of their commercial importance, based on the quan-
tities produced annually, tars may be grouped as follows, viz.:
coal tar is produced in the largest quantity, water and oil-gas tars
come next, and wood tar follows in sequence. Insignificant quan-
tities of producer-gas coal tar, bone tar, blast-furnace tar, peat-,
lignite- and shale-tars are produced in the United States. Lignite
tar is produced in comparatively large quantities in Germany. The
production of peat- and bone-tar has not assumed great importance
anywhere.

The following tars have been described in the literature, 1 pro-
duced by the destructive distillation of the corresponding substance;
but have but little commercial value :

Montan-wax tar ; 2 beeswax-tar ; tars derived from the destruc-
tive distillation of vegetable and animal oils; linoleum tar derived
from linoleum waste; cork tar; leather tar; 3 tanning residues; sea-
weed tar; sulfite cellulose tar (tall oil tar) produced from the de-
structive distillation of sulfite cellulose liquor; 4 lignin tar; amber
tar, also tars derived from other fossil resins; straw tar; tars de-
rived from seed husks and hulls; 5 tobacco tar; bagasse tar; 6 mo-
lasses tar; 7 tar from beet residues in sugar manufacture; tar from
potato residues resulting from fermentation; 8 tars from fermenta-
tion residues of various sorts; yinasse tar; anthracene-oil tar ob-
tained as residue in anthracene oil distillation; fusel-oil tar obtained
on distillation of fusel oil ; asphalt tar obtained on destructive distil-
lation of natural rock asphalts (e.g., at Ragusa, Italy; Tyrol, Aus-
tria; and at other localities), etc.

The corresponding pitches are produced by distilling the respec-
tive tars listed above ; i.e., montan-tar pitch, beeswax-tar pitch, vege-
table- (or animal) oil-tar pitch, linoleum-tar pitch, cork-tar pitch,
leather-tar pitch, tannin-tar pitch, seaweed-tar pitch, sulfite-cellulose-
tar pitch (tall-oil pitch), lignin-tar pitch, amber-tar pitch, straw-tar
pitch, seed-tar pitch, tobacco-tar pitch, bagasse-tar pitch, molasses-
tar pitch, beet-residue-tar pitch, potato-residue-tar pitch, fermenta-

XIII DESTRUCTIVE DISTILLATION 281

tion-residue-tar pitch, vinasse-tar pitch, anthracene-oil-tar pitch,
fusel-oil-tar pitch, naphthylamine pitch, cumarone pitch, cresol pitch
(carbol pitch), asphalt-tar pitch, etc.

We will now consider the various processes for producing tars
in greater detail.

DESTRUCTIVE DISTILLATION

This process is used for destructively distilling infusible organic
substances including non-asphaltic pyrobitumens, pyrobituminous
shales, wood and bones. It consists in heating the substance to a
high temperature in a still from which air is excluded, and the dis-
tillation is continued until the volatile constituents are driven off and
the residue carbonizes. The volatile constituents are grouped into
two classes, viz,: non-condensable and condensable products, the
former including the permanent gases, and the latter, the aqueous
liquor and tar.

The nature of the ingredients formed during the distillation de-
pends largely upon the nature of raw material used and the tem-
perature at which it undergoes decomposition. As a rule, the older
the substance from a geological standpoint, the higher will be the
temperature at which it decomposes. At low temperatures, we find
aliphatic (straight chain) hydrocarbons in the tar, also varying
amounts of phenolic bodies, of toluene and naphthalene, but no
benzene or anthracene. This is true in the case of peat, lignite,
cannel coal and pyrobituminous shales. Where the destructive dis-
tillation takes place at a high temperature, aromatic hydrocarbons
will predominate, including benzene and anthracene. This is true
with bituminous coals. The aqueous liquor will show an acid reac-
tion in the case of wood and peat, and an alkaline reaction with
lignite, coals and pyrobituminous shales.

In general, the yield of tar depends upon five factors, viz. : the
composition of the substance, the temperature, the time of heating,
the pressure, and upon the efficiency of the condensing system.
These will be considered in greater detail.

The Composition of the Substance, (a) The Percentage of
Volatile Constituents. The greater the percentage of volatile con-
stituents, and conversely the smaller the percentage of "fixed car-
bon," the larger will be the yield of tan Figured on the basis of

282

GENERAL METHODS OF PRODUCING TARS

XIII

&\ja vrjLitju juzw*4rf *rj.jj.msjLsu I/JT i xti/Asi/ ujxv vj .x /3*Y4j ^VXAJL

the dry weight of the non-mineral constituents, the yield of volatile
matter will range as follows, commencing with the highest: wood,
peat, lignite, bituminous coal. The yields of tar follow in the same
sequence, viz. :

Wood 10 -20 per cent

Peat 7i~i5 per cent

Lignite 5 -10 per cent

Bituminous coal , 3 - 7 per cent

(b) The Percentage of Oxygen in the Fuel. As a general rule,
the greater the percentage of oxygen in the fuel, the greater will be
the yield of tar. Georg Lunge 9 cites the following figures to show
the relation between the percentages of oxygen, tar, and water,
based on the dry weight of fuel:

Fuel Contains
Per Cent

Yield Tar,
Per Cent

Yield Water,
Per Cent

Oxygen <-6i

310

A <8

Oxygen 65-7^

4.6c

<.86

Oxygen 7J~9

c.o8

6,80

Oxygen 9-1 1

$.48

8,60

Oxygen 11-13

r, ro

7 86

The Temperature, (a} The Temperature at which the Fuel
Decomposes. As stated previously, each type of fuel has a definite
temperature at which distillation commences. The older the fuel
from a geological standpoint, the higher will be this temperature,
and hence the greater will be the yield of coke, and the smaller that
of tar. It would appear that a preliminary decomposition approach-
ing a state of fusion occurs at this temperature, which remains fairly
constant until the carbonization is complete. The coke-forming
property of bituminous coals depends upon the presence of con-
stituents melting at a lower temperature than that at which carboni-
zation occurs.

(b) The Temperature at Which the Distillation Is Performed.
This is distinct from the preceding, and is determined by the quan-
tity and intensity of the heat applied externally to the retort in
which the destructive distillation takes place. It depends upon the
nature of the heating medium, and the manner in which it is applied.
The temperature may be close to that at which the fuel undergoes

XIII DESTRUCTIVE DISTILLATION 283

distillation, or it may be vastly in excess thereof. The higher the
temperature above that necessary to cause incipient decomposition,
the smaller will be the yield of tar, and the larger that of gas; more-
over, a high temperature results in the formation of a larger per-
centage of free carbon in the tar, due to greater decomposition
("cracking") of the distillate.

Aromatic hydrocarbons, upon being subjected to a gradually in-
creasing temperature (650-800 C), are transformed as follows:

Higher benzene homologues-*Lower benzene homologues-Di-
phenyl-Naphthalene- Anthracene.

At temperatures above 800 C., the anthracene is decomposed
into carbon and gas. 10

The Time of Heating, (a) Thickness of the Fuel Layer. The
deeper the layer of fuel in the retort or furnace, the greater the
super-heating, and consequently the smaller will be the yield of tar
and the larger that of gas. When the layer is deep, the volatile
portions are compelled to pass through a mass of incandescent fuel,
so that the temperature of the gases is increased, due to the greater
time of contact. This is the underlying principle in the manufacture
of generator gas.

It follows also that the greater the area of contact between the
fuel and the heating surface, the shorter time it will take to raise the
temperature of the former the requisite degree. Small charges of
fuel may thus be heated more rapidly, which is conducive to the
formation of a greater proportion of gas and tar and a smaller yield
of coke. Slow heating, on the other hand, results in the production
of a large proportion of coke, and smaller proportions of gas and
tar respectively. It is for this reason that comparatively small and
narrow retorts are used for the manufacture of illuminating gas, and
very much larger chambers where coal is treated to obtain coke.

(b) Size of the Fuel. The size of the lumps of fuel has an im-
portant bearing on the time of heating. If the lumps are too fine,
they will pack together to such an extent that insufficient space is left
between them for the transfer of heat by the gaseous products.
On the other hand, if the lumps are too large, it will take an abnor-
mally long time for the carbonization process to reach the center of
each lump, since the heat conduction of the fuel itself is poor.

284 GENERAL METHODS OF PRODUCING TARS XIII

(c) Construction of the Retort or Furnace. The thickness of
the walls, the method of heating, the size as well as the nature of
the material of which the retort is constructed, all tend to influence
the time of heating. Small units, the use of preheated gases for
supporting the combustion, and thin retort walls constructed of ma-
terials which have a relatively high conductivity at elevated tem-
peratures, serve to decrease the time of heating.

The Pressure. The greater the pressure, the longer are the
volatile products forced to remain in contact with the hot retort and
incandescent fuel, and the greater, therefore, will be the carboniza-
tion. The use of reduced pressure hastens the removal of the vola-
tile constituents and serves to increase the outputs of gas and tar,
and reduce the yield of coke* At the same time, the period of dis-
tillation is increased. In manufacturing illuminating or fuel gas,
modern practice consists in carrying out the distillation under a
moderate vacuum. On the other hand, when the main object is to
produce coke, the pressure of the gas inside the retort is purposely
allowed to increase somewhat.

The Efficiency of the Condensing System. As the vapors leave
the retort, oven, blast-furnace, or producer at 500 to 800 C M all
the constituents exist in the gaseous state, excepting the "free car-
bon" derived from the decomposition of the gases in contact with
the highly heated walls, and the particles of mineral matter which
are carried over mechanically. The vapors are composed of a mix-
ture of substances, .some congealing to solids, others condensing to
liquids, and still others remaining as permanent gases at atmos-
pheric temperature and pressure. As the vapors cool, the solids and
liquids separate out, forming the tar. This separation is progressive,
the higher boiling-point constituents condensing first, followed by
substances of lower boiling-points, and finally liquids boiling slightly
above atmospheric temperature. With this in view, the vapors may
either be cooled slowly, or they may be cooled rapidly, so that all
condensable constituents are caught together in the form of "tar,"
to be redistilled later into its components. It is a singular fact, that
even when the vapors have been thoroughly cooled, the tar will not
separate out completely, without further treatment. Part remains
suspended in the gases as infinitesimally fine globules, known as a
"tar fog." This term is most expressive, since its behavior is very

XIII PARTIAL COMBUSTION WITH AIR AND STEAM 285

similar to that of an ordinary fog, alluding to the weather. Mere
cooling will not condense a "tar fog," accordingly other means must
be employed.

PARTIAL COMBUSTION WITH AIR AND STEAM

This takes place in manufacturing producer gas. Several forms;
of producers are in use, and peat, lignite, pyrobituminous shale, or
bituminous coal are variously employed as fuel. The reaction which
ensues may be expressed as follows, in which "C" represents the
carbonaceous matter present in the form of fuel:

The resulting gas, known as "producer gas," is composed of carbon
monoxide with a smaller proportion of hydrogen. When anthracite
coal or coke is used as fuel, no tar results ; with bituminous coal, tar
is formed in certain types of producers but not in others; and with
peat or lignite, tar is produced in all types, on account of the readi-
ness with which they volatilize at low temperatures, and the com-
paratively large proportion of volatile constituents present These
tars correspond very closely in physical and chemical properties to
the ones obtained from the corresponding processes of destructive
distillation, but with the former the yield is smaller, since most of
the tarry matter is consumed.

Lignite carrying a moderate proportion of mineral matter (e.g.,
Messel lignite) is treated in a special form of producer to obtain a
small amount of gas and the largest possible yield of tar (4 to 14
per cent) . This is brought about by introducing a limited and care-
fully regulated quantity of air and steam, sufficient only to support
partial combustion. The same method is always followed in treat-
ing pyrobituminous shales, on account of the greater intrinsic value
of the tar, of which 5 to 25 per cent is recovered. These processes
approach destructive distillation closely, the object being to bring
about incipient combustion of the lignite or shale and the non-con-
densable gases derived therefrom, thereby raising the temperature
sufficiently to cause destructive distillation.

When peat, bituminous coal or lignite containing a large propor-
tion of mineral matter* is treated in a producer, it is always intended

286 GENERAL METHODS OF PRODUCING TARS XIII

to produce the largest possible yield of gas, and the smallest pro-
portion of tar.

PARTIAL COMBUSTION WITH A LIMITED ACCESS OF AIR

This process takes place in manufacturing generator gas, also
upon smelting ores in blast-furnaces. No tar is produced in manu-
facturing generator gas, hence this process ceases to be of interest
from the bituminologist's standpoint. In the case of blast-furnaces,
no tar results when anthracite coal or coke is used as fuel, but when
bituminous coal is used, as is sometimes the practice in England and
on the Continent, 2 to 3*4 per cent of its weight of tar is produced.
The air is forced into the blast-furnace from below, and travels
upward through a comparatively thick layer of incandescent fuel.
The oxygen on coming into contact with the fuel is first converted
into carbon dioxide, which on rising through the incandescent layer
combines with more carbon, forming carbon monoxide. The heat
generated volatilizes a certain amount of the bituminous coal in the
upper layers from which the tarry matters escape unconsumed.

CRACKING OF OIL VAPORS

In manufacturing oil-gas, crude petroleum or a heavy distillate
known as "gas-oil" is sprayed under more or less pressure into a
closed retort heated to redness. This causes the oil to decompose
into a permanent gas and from 5 to 10 per cent by weight of oil-gas
tar. The reaction, known as "cracking," results in the breaking
down of the hydrocarbons present in the petroleum or gas oil into
simpler substances.

Water-gas is produced by the combustion of anthracite coal or
coke in an atmosphere of steam according to the following reaction :

The gas consists theoretically of equal volumes of carbon monox-
ide and hydrogen. It burns with a non-luminous flame, and when
intended for illuminating purposes must be enriched or "car-
bureted." The highly heated water-gas as it is generated, is ac-
cordingly mixed with a spray of crude petroleum or gas oil, then

XIII CRACKING OF OIL VAPORS 287

passed into a carburetor in which the oil becomes vaporized, and
finally through a superheater maintained at a temperature suffi-
ciently high to crack the oil vapors into permanent gases. From 2
to 10 per cent of tar is produced, based on the weight of the petro-
leum or gas-oil used. This tar is known as water-gas tar and is
similar in its physical and chemical properties to oil-gas tar.

CHAPTER XIV
WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH

WOOD TAR AND WOOD-TAR PITCH

This chapter will deal with the treatment of wood, either by
destructive distillation, or by a combination of steam and destruc-
tive distillation. 1 The treatment of resinous woods by the steam
distillation process alone, for the recovery of turpentine and other
oils, does not fall within the scope of the present treatise.

Varieties of Wood Used. From the standpoint of destructive
distillation, woods may be divided into two classes, viz.:

Hard Woods, including the maple, birch, beech, oak, poplar,
elm, willow, aspen, alder, ash, hickory, chestnut and eucalyptus.

Resinous or Soft Woods, including the pine, fir, cedar, cypress,
spruce, hemlock, larch or tamarack.

The trees from which hard woods are obtained are known as
"broad-leaved" or u deciduous trees," and those producing resinous
or soft woods are termed "coniferous trees" or "evergreens." Soft
woods are distinguished from hard woods principally in that the
former contain larger quantities of turpentine and resin. The dis-
tillation of hard wood aims at the recovery of wood alcohol, ace-
tates, tar and charcoal, whereas the distillation of resinous wood
(soft wood) is directed to the recovery of turpentine, wood-tar
oils, tar and charcoal.

In the wood-distilling industry the basis of measurement is a
cord, which is taken to equal 128 cu. ft. of the closely stacked wood
containing 15 per cent of moisture. The weight of a cord varies
with different kinds of wood, from about 1700 Ib, in the case of
white pine and poplar, to about 4000 Ib. in the case of oak.

For purposes of destructive distillation, the wood should be as
dry as possible, since during the process all the moisture must be
evaporated before the wood decomposes. The smaller the per-
centage of moisture contained in the wood, the more rapid will be
the distillation process and the smaller the quantity of fuel required.

288

XIV

WOOD TAR AND WOOD-TAR PITCH

289

It is advisable therefore, to cut and stack the green wood containing
20 to 50 per cent of moisture from six months to two years, during
which the moisture content will fall to between 12 and 25 per cent
Yields of Distillation. The following figures will give a general
idea of the average yields upon distilling a cord of the respective
classes of wood:

Hard Woods

Soft (Resinous) Woods

Turpentine

5- 25 Gal.*

Wood-tar oils

30- 75 GaL

Crude -alcohol (containing acetone)
Tar

8- 12 Gal.
8- 20 Gai

2- 4 Gal.
30- 60 GaL

Charcoal

40- 52 Bu.

25- 40 Bu.

ico-^co Lb.

50-100 Lb.

* Sawdust yields 5 to 10 gal. of turpentine and light wood 10 to 25 gal. per cord,

The tar may be classified according to the type of carbonizing
apparatus employed, as follows: mound tar, pit tar, oven tar, retort
tar and generator tar.

Hard- Wood Distillation. The following figures show the yields
of tar and charcoal from the various hard woods in percentage,
based on the dry weight of the material : 2

Tar,
Per Cent

Charcoal,
Per Cent

Hickory

13.0

37,7

Maple . .

12.8

40.6

Birch

12.

40,6

Beech

9.4.

41 ig

Oak

7.8

4$. 7

Chestnut

4 .6

47-6

.A.

In the United States, the principal centers for hard-wood dis-
tillation are in the States of Pennsylvania, New York and Michigan.
Soft-wood distillation is carried on largely in the States of Florida,
Georgia, North and South Carolina and Alabama.

The crude products of the distillation of hard wood may be
grouped into four classes, viz. :

(1) Non-condensable gases , 20-30 per cent

(2) Aqueous distillate (crude pyroligneous acid) 30-50 per cent

(3) Wood-tar oils, and wood tar 5-20 per cent

(4) Charcoal > ; * *O-45 per cent

290

WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH

XIV

Method of Distilling. When hard wood is heated in a retort,
water passes off below 150 C., after which decomposition sets in.
With soft (resinous) wood, turpentine and water commence to
distil between 90 and 100 C. and continue to 150 C., whereupon
products of destructive distillation pass over. The distillation proc-
ess is practically complete at 430 C. In the case of hard wood,
the first group of products which pass over (between 150 to
280 C.) include acetic acid, methyl alcohol and wood creosote;
the second group (280 to 350 C.) consist of non-condensable gases
(about 53 per cent of carbon dioxide, 38 per cent of carbon monox-
ide, 6 per cent of methane, 3 per cent of nitrogen, etc.) ; the third
group (350 to 400 C.) are composed of solid hydrocarbons and
their derivatives. The yields of methyl alcohol and acetic acid in-
crease with a rise of temperature up to 300 C. beyond which they
decrease; moreover their yield is greater when the wood is heated
slowly, than when the distillation is forced.

The following fractions are obtained on distilling beech-wood
tar (specific gravity at 15 C. 1.05-1.10) :

Aqueous distillate (*) 15-20 per cent

Light tar oils (to 110 C.) 5-10 per cent (sp. gr. o. 90-0. 98)

Heavy tar oils (120-270 C.) 10-20 per cent (sp. gr. i .04-1 .05)

Soft wood-tar pitch 40-60 per cent

* Containing 10 per cent acetic acid and 3-5 per cent crude wood alcohol.

In distilling hard woods,
large rectangular iron retorts
are used, measuring 6 ft in
width, 7 ft. high and either 27
or 50 ft. long, depending upon
whether they are intended to
hold 2 or 4 carloads. The re-
torts are set in brickwork, and
provided with large air-tight
iron doors at the ends. The
wood is loaded on small iron
cars holding between I and 3
cords each (Fig. 91) which

are run on tracks directly into the retorts.

The arrangement of a modern wood-distilling plant is shown in

Fig. 92; where A represents a car; 5, the retort; C, first cooler; JD,

FIG. 91. Iron Cars Used in the Distilla-
tion of Hardwood.

XIV

HARD-WOOD DISTILLATION

291

second cooler; E 9 the acetate drying floor; a, condensers; b. liquor
trough; c } gas main to boilers; i, fuel conveyor; w, fireplace; w, ash
pit; o, hinged spout to deliver fuel from i to m. After the retort
is charged, the doors are closed and heat applied slowly, either by

FIG. 92. Modern Wood Distilling Plant.

FIG, 93. Plant for Refining Wood Tan

burning the non-condensable gases resulting from the distillation
process, or by atomizing the tar underneath the retort with a jet of
steam. Unless the gases are stored in a gas-holder, the process is
started by burning a small amount of wood on an auxiliary grate
beneath the retort.

292

WOOD TAR, WQOto-fAR PlTCti AND ROSIN PITCH

XIV

The vapor from the retort is passed through condensers, where
the pyroligneous acid, alcohol and other condensable constituents
are recovered. These are conveyed to large settling tanks, and al-
lowed to rest quietly until the tar settles out

The distillation process continues from twenty to thirty hours,
whereupon the fires are extinguished and the retort allowed to cool.
The small iron cars now carrying charcoal are quickly run from the
retort into large iron coolers, similar in size and shape to the retort
itself, and the doors are closed to prevent access of air.

Refining Processes. The general arrangement of a refining
plant is shown in Fig. 93, where A 12 represents the raw liquor
vats, B 15 represent the raw liquor settling tanks, C i the tar
still, C 23 the raw liquor still, D 1-2 the neutralizing vats,
E 13 the lime-lee stills, F 13 the alcohol stills, G the weak alcohol
storage tank and H the strong alcohol storage tank. Table XVII
shows a diagrammatic outline of the products obtained upon distill-
ing hard wood, and refining its distillates.

TABLE XVII

HARD WOOD

Distilled Destructively

Non-condensable Gases
(Burned under retort)

Condensable Distillate
Separated by settling into:

Charcoal Residue

Crude Aqueous Portion
Separated by distillation into:

Raw Tar
Distilled into:
1

i' I
Distillate, known as Tarry Residue

Distillate of

I
Residue of
Boiled Tar
^ Redistilled

KfoiitrnliTiwl with Hm* nnrl rliVfillorl ^^li _ *.

illate composed of Residue composed of crude
Tude dilute wood acetate of lime. Converted

i i i

Light oil Heavy oil Residue of
Wood-tar pitch

alcohol containing
acetone. Rectified
into:

by roasting into gray acetate
of lime. Then treated by
one of the following methods

11 A

Acetone Wood alcohol Distilled with G
Sulf uric acid o

mverted into
ther acetates

Distilled at a high
temperature alone

. i,

1 i

I i

Distiflate of

Residue of

Other

Acetone Light

Heavy Residue of

Acetone

Calcium

Acetates

Acetone

Acetone Calcium

Sulfate

Oils

Oils Carbonate

XIV HARD-WOOD DISTILLATION 293

After the pyroligneous acid and tar have been separated by set-
tling, the crude products are distilled independently to recover any
pyroligneous acid from the crude tar, and conversely, any tar re-
tained by the crude pyroligneous acid (dissolved in the alcohol and
acetone present). The method consists in heating the tar with
steam in closed coils until the water is driven off, and then blowing
live steam thrpugh the charge. 3

A continuous process, known as the "Badger-Stafford Process," 4
has been devised for treating scrap wood obtained in other manu-
facturing operations. The hogged scrap wood (averaging 70 per
cent maple, 25 per cent birch and 5 per cent ash, elm and oak) is
first passed through six rotary driers heated by flue gases entering
at 600 F. The scrap wood is discharged from the driers at 302 F.
and then fed into retorts 40 feet high and 10 feet in diameter. Air-
tight valves at the top and bottom allow the introduction of the
wood and the removal of the charcoal, respectively, without escape
of gas, which passes off at the top of each retort to four condensers
mounted around it. The average temperature in the central zone is
950 F., and at the bottom 490 F.

The products from the retorts are charcoal, which is passed to
coolers and conditioners; pyroligneous acid or "green liquor," which
is pumped from the condensers to the primary separators; and non-
condensable gas, which is used for heating the retorts and burned
under the boilers.

Each ton of wood produces 1 1 1 gal. of pyroligneous acid con-
taining approximately 4.5 per cent methanol and 12.5 per cent acetic
acid, also allyl alcohol, acetone, methyl acetate, suspended and dis-
solved tar, various oils and water. The pyroligneous acid is first
delivered to settling tanks where the suspended tar is largely re-
moved, and then pumped to the primary tar stills. The acid distil-
late from these stills is returned to the settling tanks, while the dis-
tilled heavy tar is sent to the pitch still, where creosote oil and pitch
are recovered by distillation under a vacuum of 27 inches with the
use of steam at 125 Ib. pressure.

The pyroligneous acid free of settled tar is distilled in six large
batch primary stills operating on a 30 hour cycle. The soluble tar
remaining as a residue in these stills is pumped under the boilers
where it is burned. The acid distillate passes to a separator where

294

WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH

XIV

the acid oils are removed, then through a sand filter, and finally to
the continuous stills, which yield crude 95 per cent methanol at the
top of thg column and 15 per cent acetic acid at the bottom. The
crude methanol, which contains allyl alcohol, acetone, methyl acetate
and alcohol oils, is first fractioned in two discontinuous stills, which
yield refined allyl alcohol and alcohol oils as final products, while
a 50 per cent methyl acetone, an intermediate methyl acetate, and a
99 per cent methanol are sent to the four-column continuous stills,
which in turn yield 75 per cent methyl acetone, 75 per cent methyl
acetate and C.P. methanol.

The 15 per cent acetic acid obtained from the first continuous
de-alcoholizing distillation is used directly in the production of
ethyl acetate from ethyl alcohol in the presence of sulfuric acid.

A flow-sheet of the process is illustrated in Table XVIII.

TABLE XVIII

FROM CARBONIZATION BUILDING

CRUDE METHANOL

ETHYL ALCOHOL

I | PLUS LIME |

ETHYL FORMATE

*j WEAK ACETIC ACID

PLUS CALCIUM CLORIDE '

IPLUS SULPHURIC ACID 1 | CRUDE ETHYL ACETATE | ^{

| PLUS LIME

| DRY ETHYL ACETATE f*^

HEAVY ACID OIL

ALLYL ALCOHOL

FINISHED KETONES

1WASHED ALCOHOL OIL

HIGH BOILING ESTERS

85% ETHYL ACETATE

| HEAVY NEUTRAL 01 L"

LIGHT ACID OIL

The following table gives the yields of the various intermediate
and{inal products per ton of dried wood treated:

INTERMEDIATE PRODUCTS

Total 100% spirits, gallons. .

FINAL PRODUCTS

Charcoal, Ibs 600

Non-condensable gas, cubic feet (290

B.t.u. per cubic foot) 5000

5,0 C, P. methanol, gallons 3.118

Methyl acetone, gallons o. 653

Allyl alcohol, gallons o. 048

Ketones, gallons 0.126

Methyl acetate, gallons o. 945

Soluble tar, gallons 22.0

XIV

SOFT-WOOD DISTILLATION

295

Settled tar, gallons n .o

Acetic acid (as 100%), Ibs 101 .0

Pitch, Ibs 66.0

Creosote oil, gallons 3.25

Ethyl acetate, gallons. 14-65

Ethyl formate, gallons i . 27

Various other processes have been devised for distilling wood
waste in the production of wood tar involving the treatment of
sawdust, shavings, splittings, wood bark, roots, refuse of one kind
or another. 5

The dehydrated tar, known as "boiled tar" or "retort tar,"
amounting to between 3 and 10 per cent of the weight of the wood,
may be utilized in one of the following ways:

( i ) It may be sold as such, and used for preserving wood.

? 2 ) It may be burned under the retorts as fuel.

(3) It may be subjected to fractional distillation to recover the
light oils boiling below 150 C, heavy oils boiling between 150
and 240 C., and the residual pitch constituting between 50 and 65
per cent by weight of the tar. The light oils are used as solvents in
manufacturing varnish, and the heavy oils after further refining are
marketed as commercial wood creosote which finds a sphere of use-
fulness as a disinfectant, wood preservative, and flotation oil.

Soft (Resinous) Wood Distillation. Method of Distilling. In
treating soft wood (resinous wood )a different method is followed.
Iron or steel retorts varying
in capacity from one to four
cords are used, constructed
either vertically or horizon-
tally, as shown in Fig. 94.
Low - pressure superheated
steam, or saturated steam un-
der high pressure, is intro-
duced into the retort to re-
move the turpentine, and then
the volatile oils (known as
"heavy oils") leaving a resi-
due of coke behind. Three classes of resinous wood are used for
the purpose:

( I ) "Light wood" containing comparatively large quantities of
turpentine.

FlG. 94. Retorts for Distilling Soft Wood.

296 WOOD TAR, tPOOD-TAR PITCH AND ROSIN PITCH XlV

"Stumps/' which also contain more or less turpentine
Saw-mill waste, which is rather poor in turpentine.

The wood is first "hogged/* or in other words, cut into chips
before it is introduced into the retort. The temperature is raised
gradually to 200 C. as the steam passes through the retort Water
and crude turpentine distil over first and are separated by settling.
As the temperature rises above 200 to 220 C. the wood commences
to decompose into tarry substances, and at about 250 C. the resins
present break up into "rosin spirits" and "rosin oils," Both the
crude turpentine and the heavy oils are redistilled separately, the
former producing purified wood turpentine and the latter pine oil,
rosin oil and pitch. Rosin spirits boils between 80 and 200 C,
wood turpentine between 150 and 180 C., pine oil between 190
and 240 C, and rosin oil between 225 and 400 C. This process
is illustrated diagrammatically in Table XIX.

TABLE XIX

LIGHT WOOD (PINE OR. RESINOUS WOODS)
Steam distilled up to 200 C., and then distilled destructively

Water Below 200 C, Above aoo C.

Condensable Distillate. Redistilled into: Destructive distillation occurs

I I | I i

Light oils Heavy oils Non-condensable Condensable Charcoal

(Fractioned) (Fractioned) gases Distillate Residue

| J ^ J J I Treated the same as in

Rosin Wood Part of Balance of Rosin Pine-tar Hard wood distillation

Spirits Turpentine Pine oil Pine oil oils pitch (See Table XVII)

In some cases the "light wood" is subjected to a process of
destructive distillation without using steam. The temperature is
raised slowly and the distillate under 200 C, caught separately to
avoid contamination with tarry matters. After the temperature
rises above 200 C., the process follows the same course as for hard-
wood distillation.

Refining Processes. The distillate under 200 C. is fractioned
into light and heavy oils respectively. The light oil is in turn redis-
tilled to recover the rosin spirits, wood turpentine and a part of the

XIV SOFT -WOOD DISTILLATION 2&7

pine oil. The heavy oil is similarly redistilled to separate the pine
oil, rosin oil and a part of the pitch. The crude tar obtained above
200 C, is distilled to recover any acetic acid, and the residue either
marketed as "pine tar" or distilled to separate the light and heavy
oils from the pine-tar pitch obtained as residue. A pitch-like prod-
uct may be obtained upon blowing rosin oil with air and superheated
steam. 8

Another treatment of soft wood consists in subjecting it to an
extraction process with solvents, which are recovered and used over
again. In this process, the wood is first ground into small frag-
ments, which may either be treated as such, or else subjected to a
treatment with live steam to remove the volatile f oils, including the
turpentine and pine oil. The rosin is extracted with hot petroleum
naphtha or benzol. The extract is thereupon distilled to remove
the solvent (also the turpentine and pine oil, where the wood was
extracted directly, without steaming). The rosin is extracted from
the residue by means of a petroleum solvent (sometimes after first
purifying by dissolving In furfural and subsequent evaporation),
leaving a form of wood pitch which tests as follows :

(Test 15^) Fusing-point (R, and B. method) 195-240 F.

(Test 23) Soluble in 88 petroleum naphtha 10-20 per cent.

(Test 370) Acid value 11-115

(Test $jd) Saponification value 140-170

(Test 37*) Saponifiable constituents 9*-95 per cent.

The wood, after treatment in this manner, may either be distilled
destructively, or used as a fuel, or used as a filler in other manufac-
turing operations,

Wood Tars, The bituminous products derived from the de-
structive distillation of wood are designated commercially as hard-
wood tar and pine tar ; hard-wood-tar pitch and pine-tar pitch.

Wood tar has also been termed "Stockholm tar" and "Arch-
angel tar."

Hard-wood Tar and Pine Tar. The physical and chemical
characteristics of the tars and corresponding pitches vary, depend-
ing upon the kind of wood used, as well as the exact method of
treatment The following figures will give a general idea of the

208 WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH XIV

characteristics of the dehydrated hard-wood tar and pine tar ordi-
narily encountered in the American market :

HARDWOOD PINE TAR (FROM
TAR RESINOUS WOODS)

.(Test i) Color in mass ..Black Brownish

(Test 7) Specific gravity at 77 F i . 10-1 , 30 i , 05-1 . 10

(Test 8) Viscosity Fairly liquid Viscous

(Test 9) Consistency at 77 F Liquid Liquid

(Test 15) Fusing-point. U Below 20 F. Below 50 F.

(Test 1 6) Volatile matter at 500 F., 5 hrs. . , 35-60 per cent 40-7 5 per cent

(Test 170) Flash-point 5-75 F- 60-90 F.

(Test 19) Fixed carbon 5- ao per cent 5- 15 per cent

(Test ai) Solubility in carbon disulfide 95-100 per cent 98-100 per cent

Non-mineral matter insoluble o- 5 per cent o- 2 per cent

Mineral matter o- i per cent o- x per cent

(Test 22) Carbines o- 2 per cent o- 2 per cent

(Test 23) Solubility in 88 petroleum naphtha 50- 90 per cent 65- 95 per cent

(Test 28) Sulfur o.o per cent o.o per cent

(Test 30) Oxygen 2-10 per cent 5-10 per cent

(Test 32) Naphthalene None None

(Test 33) Solid paraffins None None

(Test 34*) Sulfonation residue Trace to 5% Trace to $%

(Test 37*) Saponifiable constituents 25-85% 20-60%

(Test 37jr) Resin acids Up to 15% Up to 30%

(Test 39) Diazo reaction Yes Yes

(Test 40) Anthraquinone reaction No No

(Test 41) Liebermann-Storch reaction Yes Yes

According to David Holde, on shaking wood tar with water,
the aqueous extract will react acid (due to the acetic acid present),
and upon adding a few drops of ferric chloride, will at first form a
green and then a bluish- to brownish-green coloration. Birch-bark
tar gives a green color with ferric chloride, which on addition of
ammonia changes to an intense blue ; whereas birch tar gives a brown
color. Both hard-wood tar and pine tar are almost completely
soluble in absolute alcohol, glacial acetic acid and acetic anhydride.
On subjecting wood tar to distillation, the first portion passing over
shows 3, separation of water which will react acid. On continuing
the 4* s tiM at i n > oily matters are obtained which dissolve readily in
alcohol, and on treatment with concentrated sulfuric acid become
converted into wate^-soluble substances. Pine tar has a high acid
value, since it often contains as much as 30 per cent by weight of
res}n acids, and is characterized by the absence of sulfur, paraffins,
naphthalene and anthracene; and by the presence of phenol (Test
39) and resin acids (Test 41) which causes it to have a high acid
value (Test 374) and give an acid reaction to litmus.

XIV WOOD-TAR PITCHES 299

The following constituents have been identified in German tars : T

BEECHWOOD PINE

TAR TAR

Per Cent Per Cent

Unsaponifiable matter 18.0 53.5

Saponifiable matter:

Hydroxy acid anhydrides 9.5 o.o

Hydroxy acids 52.3 14.0

Resin acids 7.7 17.0

Reported as fatty acids* 3.2 6.0

Phenols 9.3 9.5

Total 100,0 loo. o

* Separated by TwitchelTs method, but not true fatty acids.

Wood-tar Pitches. Hard-wood-tar pitch and f>ine-tar pitch vary
in their physical properties, depending upon the following cir-
cumstances :

1 i ) The variety of wood used.

(2) The method by which the wood is distilled, including the
temperature, its duration, the kind of retort, etc,

(3) The extent to which the tar is distilled in producing the
pitch. The further it is distilled, the harder will be the pitch and the
higher its fusing-point.

Hardwood-tar Pitch and Pine-tar Pitch. These comply with
the following characteristics :

PINE-TAR PITCH

HARDWOOD-TAR (FROM RESINOUS
PITCH WOOD)

(Test i) Color in mass Black Brownish black

(Test 2) Homogeneity Uniform Uniform

(Test 4) Fracture Conchoidal Conchoidal

(Test 5) Lustre Bright to dull Bright to dull

(Test 6) Streak Brown to black Brown

(Test 7) Specific gravity at 77 F i , 20-1 .30 1 , 10-1 . 15

(Test gb) Penetration at 77 F 0-60 0-60

(Test gc) Consistency at 77 F 10-100 10-100

(Test 9</) Susceptibility index > ico > 100

(Test 10) Ductility Variable Variable

(Test 1 50) Fusing-point (K. and S. method).. 100-000 F, 100-000 F,

(Test 15^) Fusing-point (R. and B. method). . 1 15-005 P. 115-005 F,

(Test 1 6) Volatile matter Variable v Variable

(Test 19) Fixed carbon I5~35 PC* cent 10-05 per cent

(Test 01) Soluble in carbon disulfide 3-95 per cent 40-95 per cent

Non-mineral matter insoluble 5-70 per cent 0-60 per cent

Mineral matter , o-i per cent 0*1 per cent

800 WOOD TAR, WOODTAR PITCH AND ROSIN PITCH XIV

PINE-TAR PITCH

HARDWOOD-TAR (FROM RESINOUS
PITCH WOOD)

(Test aa) Carbenes 2-10 per cent 0-5 per cent

(Test 23) Solubility in 88 petroleum naphtha 1 5-50 per cent 25-80 per cent

(Test 28) Sulfur o per cent o per cent

(Test 30) Oxygen in non-mineral matter 1-5 per cent 2-8 per cent

(Test 32) Naphthalene None None

(Test 33) Solid paraffins. None None

(Test 340) Sulfonation residue 0-5 per cent 0-3 per cent

(Test 37*) Saponifiable constituents 60-95 per cent 45-75 per cent

(T$st37) Resin acids Up to 20 per cent Up to 40 per cent

(Test 39) Diazo reaction Yes Yes

(Test 40) Anthraquinone reaction No No

(Test 41) Liebermann-Storch reaction Yes Yes

The following constituents have been identified in German
pitches : 8

HARD BEECHWOOD- MEDIUM HARD

TAR PITCH, PINE-TAR PITCH,

Per Cent Per Cent

Unsaponifiable matter 6.0- 6.3 19.7

Saponifiable matter:

Hydroxy acids and anhydrides 77o- 65 .3 31 . 8

Resin acids o.o- o.o 35.2

Neutral tar resins 14.0- 25.4 1.5

Reported as fatty acids * 1.5- 1.5 a. 8

Phenols 1.5- 1.5 8.0

Mineral matter o.o- o.o I .o

Total 100. o 100,0 100,0

* Separated by TwitchelTs method, but not true fatty adds.

Soft and medium hard wood-tar pitches are fairly soluble in
ethyl alcohol, and as the hardness increases the solubility decreases.
Hard pitches are only sparingly soluble.

According to Benson and Davis, 9 wood-tar pitches are more
soluble in acetone than in carbon disulfide. Thus, hardwood-tar
pitches were found to be 15.631.9 per cent more soluble in acetone
than in carbon disulfide, and pine-tar pitches (obtained from the
Douglas fir) 8.0 to 57.8 per cent more soluble in the former solvent.

Wood-tar pitches are characterized by their extreme suscepti-
bility to changes in temperature, by the fact that they appear hard
and at the same time show a surprisingly low fusing-point, 10 and are
characterized by the absence of sulfur, paraffins, naphthalene and
anthracene. Wood-tar pitches are notoriously non-weatherproof.
They are extremely susceptible to oxidation on exposure to the
weather and are soon converted into a lifeless and pulverulent mass.

XIV ROSIN PITCH 301

However, their physical properties and weather-resistance may be
improved by fluxing with cashew-nut-shell oil, 11 or by blending with
fatty-acid pitch, which latter may be accomplished by heating to-
gether pitches of the same fusing-points, respectively, 12

Wood tar may be hardened and made more suitable for use in
black paints by treating with concentrated sulfuric acid removing
the water-soluble substances, 13 and the product may be dissolved
in acetone or methyl alcohol for use as lacquers. 14 Artificial
resins may also be produced by treating wood tar with formaldehyde
in the presence of a catalyst, 15 or by heating wood tar with 10 per
cent zinc oxide at 110 C., 16 or by treatment with chlorine in the
presence of A1C1 3 as catalyst, 17 in which latter case the product is
soluble in methyl alcohol. Wood tars may be hardened by heating
with sulfur, 18 or by blowing with air in the presence of a small
amount of sulfur, 19 or by blowing with air, ozonized air or oxygen
at 120-150 C 20

Wood tars have been utilized for the production of tar soaps,
lubricants, flotation agents, pharmaceutical products, etc. 21

ROSIN PITCH

Raw Materials Used. The sap of the long-leaf pine, known
chemically as an oleo-resin, is composed of a mixture of spirits of
turpentine and rosin. It is gathered by incising the bark one-half to
one inch, whereupon the oleo-resin slowly exudes and is collected in
small cups.

The oleo-resin is then distilled to separate the spirits of turpen-
tine from the rosin. The apparatus ordinarily used in the United
States for this purpose is shown in Fig. 95, consisting of a simple
type of copper still with a "worm" condenser. The capacity of the
still varies from 10 to 40 barrels, and usually between 15 and 20,
After the still is charged, the fire is started, and a mixture of spirits
of turpentine and water (since the oleo-resin contains between 5
and 10 per cent of water) appears in the condenser. When all the
water has boiled over, additional quantities are added in a small
stream during the distillation, since the introduction of water causes
the turpentine to boil at a lower temperature and prevents over-
heating, improving both the color and yield of the turpentine and
rosin. Towards the end of the distillation the stream of water is

302

WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH

XIV

shut off, and the rosin heated until all the moisture is expelled,
usually between 300 and 400 F. Before cooling, any foreign mat-
ter is skimmed off the surface of the rosin, after which it is strained
through a fine mesh screen and barreled, 22

Method of Distilling. Rosin, deprived of its turpentine, when
heated in a closed retort undergoes destructive distillation, yielding
a gas, an aqueous liquor 'and an oily distillate which may be sepa-
rated into several fractions. If the process is carried to completion,
coke will be left as residue. If the distillation is terminated before
the formation of coke, a pitchy residue will remain, known com-
mercially as "rosin pitch."

The rosin may be distilled either with or without superheated
steam. If the latter is employed, the quality of the distillate is im-

FIG. 95. Retort for Distilling Rosin.

proved, and a much better temperature control obtained. Distilla-
tion under vacuum is also used in many cases. The rosin may ac-
cordingly be distilled by any of the following processes :

( i ) At atmospheric pressure without steam.
(2)* With superheated steam.
(3) Under vacuum.

When the temperature of the rosin reaches 150 C. a liquid
distillate appears which separates into two layers, the lower con-
taining acetic acid, also other organic acids dissolved in water, and
the upper composed of oily substances known as u rosin spirits" or
"pinoline." When the temperature reaches 200 C. the receiver is
changed, and the distillate which ensues is either collected together
or separated into fractions. The temperature of the residue in the
retort is permitted to reach 350 to 360 C. but never to exceed the
latter. The distillate between 200 and 360 C. known as "rosin
oil.* 1 mav be separated into various fractions termed "yellow rosin

XIV ROSIN PITCH 303

oil," "blue rosin oil," "green rosin oil," etc., depending upon their
respective colors.

Products Obtained. In distilling rosin destructively at atmos-
pheric pressure, the following products are separated:

Non-condensable gases 9.0 per cent

Acid liquor 3.5 per cent

Rosin spirits or pinoline 3.5 per cent

Rosin oil 67.0 per cent

Rosin pitch 16.0 per cent

Loss (rosin adhering to walls of still, etc.) i .o per cent

According to Victor Schweizer, 23 when rosin is distilled with
superheated steam, the following yields are obtained:

Acid liquor 5.5- 5. 8 per cent

Rosin spirits 1 1 . 25-12 . o per cent

Blue rosin oil 49 ,o -50. 5 per cent

Brown rosin oil 10 . 25-10. 65 per cent

Rosin pitch 18.0 -19.0 per cent

The rosin pitch is run from the still while it is hot, and allowed
to cool in a suitable receiver,

Properties of Rosin Pitch. It is fairly uniform in composition
and conforms with the following characteristics :

(Test i) Color in mass Black

(Test 2) Homogeneity Uniform

(Test 4) Fracture Conchoidal

(Test 5) Lustre Dull

(Test 6) Streak Light yellow to brown

(Test 7) Specific gravity at 77 F i .08-1 .15

(Test 9^) Penetration at 77 F 0.5 ^

(Test 9^) Consistency at 77 F 50-100

(Test gd) Susceptibility index Greater than 100

(Test iof) Ductility at 77 F o

(Test i$a) Fusing-point (K. and S. method) 120-200 F.

(Test 15^) Fusing-point (R. and B. method) 135-225 F.

(Test 16) Volatile matter, 500 F., 5 hrs 10-18 per cent

(Test 17) Flash-point Above 250 F.

(Test 19) Fixed carbon 10- 20 per cent

(Test 21) Soluble in carbon disulfide 98-100 per cent

Non-mineral matter insoluble * o- 2 per cent

Mineral matter o- i per cent

(Test 22) Carbenes o- 5 per cent

(Test 23) Solubility in 88 petroleum naphtha 90-100 per cent

(Test 28) Sulfur o.o per cent

(Test 30) Oxygen in non-mineral matter 5-10 per cent

(Test 33) Solid paraffins o.o per cent

(Test 340) Sulfonation residue 0-5 per cent

(Test 37*) Saponifiable constituents 25-95 per cent

(Test 39) Diazo reaction Yes

(Test 40) Anthraquinone reaction No

(Test 41) Liebermann-S torch reaction Yes

304 WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH XIV

Rosin pitch is very much like rosin in its physical properties. It
is extremely susceptible to temperature changes, and as ordinarily
produced, is hard and friable at 77 F. It is characterized by the
presence of considerable quantities of unaltered resin acids (10 to
45 percent), and is free from fatty acids, glycerol, sulfur and paraf-
fin. It withstands weathering very poorly, and has therefore but a
limited use, including the lining of barrels and casks ("brewers'
pitch") . Upon being heated, it passes rapidly from the solid to the
liquid state, forming a melt of low viscosity. A product similar to
rosin pitch may be produced by heating rosin with sulfur at 250 C. 24
Burgundy pitch" is the name applied to the oleo-resin which
exudes from the Norway spruce (Abies excelsa}, found in the
Vosges Mountains and in the Alps; also from a species of pine ob-
tained in the United States (Pinus australis). The crude oleo-resin
is melted by boiling with water, and strained to remove any par-
ticles of bark or other impurities. It then constitutes the so-called
"Burgundy pitch" (Fix abietina], sometimes marketed under the
name "Vosges pitch/' These terms are misnomers, since the ma-
terial is not a true "pitch," but in reality an oleo-resin. It contains
more or less spirits of turpentine, which escaped expulsion during
the boiling process, also a quantity of emulsified water imparting to
it an opaque, yellowish-brown color. In consistency it is a more or
less brittle solid, largely susceptible to temperature changes. In
summer it softens and gradually flows, and in winter it appears very
hard and brittle. It melts easily, decrepitating because of the water
present, and has a strong odor because of the associated spirits of
turpentine. On aging it loses its opacity, due to evaporation of the
emulsified water, and turns first to a translucent, and then to a trans-
parent brown color, similar to that of rosin. Its composition is
substantially the same as rosin, containing in addition, spirits of
turpentine and emulsified water.

CHAPTER XV

PEAT AND LIGNITE TARS AND PITCHES

PEAT TAR AND PEAT-TAR PITCH

Formation of Peat. Peat * is derived from the decomposition
of vegetable matter in swampy places, such as marshes and bogs.
On the surface we find the growing aquatic plants; somewhat deeper
we find their decayed remains; and still deeper a dark colored pasty
substance containing a substantial percentage of moisture and con-
stituting the crude peat. The plants which result in the formation
of these deposits are mainly aquatic, including marine grasses, reeds,
rushes, hedges and various mosses. The transformation is caused
partly by oxidation in the presence of moisture, and also to some
extent by the action of certain forms of bacteria, molds and fungi.
As the mass of peat builds up in thickness, the lower layers are first
compacted by the resulting pressure, and then gradually carbonized.
The essential condition to peat formation is that the vegetable re-
mains shall be deposited at a rate exceeding that of their decompo-
sition. This does not prove to be the case in very warm climates,
where the remains are entirely decomposed. The organic matter
should only be partly decomposed, and since the products of partial
decomposition act as a preservative to inhibit further decay, we can
readily understand why the building up of peat beds is cumulative.
It progresses most rapidly at a mean atmospheric temperature of
45 F M which accounts for the fact that no peat bogs occur between
the latitudes of 45 N., and 45 S. It is estimated that there exist
in the United States 20 million acres of peat bogs, 30 million acres
in Canada, 50 million on the continent of Europe, also approxi-
mately 3 million in Ireland.

Varieties of Peat. The following constitute the most important
varieties of peat, based on the locality in which they are found :

(i) "Hill peat, n found at mountain tops and derived from
plants consisting of sphagnum and andromeda mosses, likewise
heath,

305

306 PEAT AND LIGNITE TARS AND PITCHES XV

(2) "Bottom peat," found near rivers, lakes, etc., in the low-
lands, including: (a) dark peat, approaching lignite in composition,
occurring at the lower parts of the deposit; (b) middle peat, which
is lighter in color and in weight than the preceding; (c) the top
stratum, which has a fibrous structure.

Peat varies in color from light yellowish, through various tints
of brown, to brownish black or black, all of which appear deeper
when the peat is moist The lighter shades generally darken to
brownish black or black upon exposure to air ; due largely to oxida-
tion* In texture, peat varies from light porous matter having a
fibrous or woody structure, to substances which are amorphous and
clay-like when wet, but appearing quite hard and dense upon drying.
When recently formed, the peat beds are but loosely compacted, but
as they accumulate, the under layers become compressed, so what
once was a foot thick may be concentrated to several inches. In
other cases the beds become covered with sedimentary rocks, which
augment the pressure, and gradually transform the peat into lignite.

The chemical composition of peat is but little understood. It is
regarded as a mixture of water, inorganic matter (calcium and iron
compounds), vegetable fibers and humus acids (such as humic,
ulmic, crenic, apocrenic, etc.). According to H. Borntrager 2 the
black varieties contain between 25 and 60 per cent of humic acids,
30 to 60 per cent of fiber, and 3 to 5 per cent of ash. Nitrogenous
compounds are also present, varying from I to 3 per cent of the
dry weight, resulting partly from the associated animal matter, and
also due partly to the humic acids combining with atmospheric nitro-
gen, forming what are known as azo-humic acids. Sulfur is also
present in amounts between o.i and 5,3 per cent based on the dry
weight.

Resinous substances are found in certain varieties of peat, to
which various names have been assigned, also bodies of a waxy
nature derived from the associated gelatinous algae, known as
"sapropel." In time, sapropel is converted into a coal-like sub-
stance, known as sapropelite, or sapropelite coal, which has been
regarded as the progenitor of cannel coal and boghead coal.

Methods of Collecting Peat. Peat is generally collected by
cutting trenches through the bog with a spade, and removing it in
sods about 3 to 4 ft. long. The deposits are worked in steps or

XV PEAT TAR AND PEAT-TAR PITCH 307

tiers. Mechanical excavators and dredges have also been used for
the purpose. The sods are allowed to drain, then air-dried and
finally heated to a high temperature in either stationary or revolv-
ing ovens, to remove the water. Peat as freshly mined contains 75
and 90 per cent by weight of water, which must of necessity be
removed before the product can be used as a fuel. Air-dried peat
carries 10 to 15 per cent of moisture, and the artificially dried
peat between a trace and 80 per cent of mineral ash, consisting
principally of sand and clay with smaller quantities of iron oxide,
calcium and magnesium salts. The maximum quantity of ash usually
considered allowable when used as a fuel is 25 per cent of the dry
weight. Peat with less than 5 per cent ash is considered good, be-
tween 5 and 10 per cent as fair, and over 10 per cent as poor,
with peat containing less than 10 per cent of ash in the moisture-
free state, the fixed carbon varies between 15 and 35 per cent,
averaging about 30 per cent.

Dehydrating Processes. It is customary to briquette the partly
dried peat, carrying 10 to 15 per cent of water, and then continu-
ing the drying until practically all the moisture is removed, and the
residual peat compacted into tough briquettes suitable for use as
fuel. It is briquetted under a pressure of 18,000 to 30,000 Ib. per
square inch, which generates sufficient heat to liberate some of the
tarry compounds of the peat, causing the sides of the briquettes to
assume a highly polished glaze. The product is claimed to have
a calorific value almost equal to that of coal. Various mechanical
contrivances have been devised for removing the water and mois-
ture from peat.

In Europe and Canada, attempts have been made to utilize air-
dried peat for generating producer gas. Various types of apparatus
have been devised for the purpose, which result in the recovery of
i to 2 per cent of peat tar, based on the dry weight of the peat 8
In generators (e.g., Mond gas generators) from '8 to 9 per cent of
tar is recovered, and in low temperature distillation processes from
8 to 25 per cent is recovered.

Methods of Distilling. Various methods have been used for
distilling peat, similar to those employed for treating coal. Dried
peat may be destructively distilled in closed retorts, obtaining a gas
suitable for use as a fuel, likewise tar, ammonia, and a good grade

308 , PEAT AND UGNITE TARS AND PITCHES XV

of coke, but in the United States this process has only been carried
on in a small experimental way. There are two classes of peat tar,
lamely retort peat tar and producer peat tar, both of which are
low-temperature products generated at not exceeding 600 C At
the present time the cost of drying and briquetting peat brings its
price higher than that of bituminous coal. For these reasons neither
peat tar nor peat-tar pitch are produced in commercial quantities.
The following represent the percentages by weight of by-prod-
ucts obtained per ton of the air-dried peat:

Gases and loss Ia -ao per cent

Aqueous liquor 30-40 per Cent

Peat tar 2-10 per cent

Coke 30-40 per cent

100 per cent

The composition of an average specimen of peat tar is as
follows :

Insoluble in ether (i.e., oxy-acids and their esters, also iron and cal-
cium derivatives) 3 per cent

Soluble in ether:

5 per cent

Unsaponifiable substances:

Solid portion 8 per cent

Liquid portion 55 p cr cent

Saponifiabie substances:
Oxy-^cids

Insoluble in ether 3 per cent

Soluble in ether 8 per cen t

Fatty acids 10 per cent

Phenols , 3i per cent

4i per cent

Total 100 per cent

The following yields are obtained from German peat:

Water-free peat tar 4 , 9 to 9,9 per cent

Light oils (sp. gr, o. 820-0. 835) 7-3 to 34. 6 per cent

Heavy oils (sp. gr, 0.830-0.885) 19.6 to 36.0 per cent

Paraffin '. 3.3 to 46.0 per cent

Peat-tar pitch 12.8 to w. 6 per cent

Creosote oil and loss 6.2 to 40.5 percent

Refining Processes. The tar is separated from the aqueous
liquor by heating the mixture with steam to the melting-point of the
tar, which then rises to the surface. It is a black, viscid liquid
with a disagreeable acrid odor, representing a to 20 per cent of

PEAT TAR AND PEAT-TAR PITCH

309

the dry weight of the peat used. The aqueous liquor contains am-
monia salts, acetic and other organic acids, wood alcohol, and pyri-
dine bases. The tar is slowly distilled, and after the water ceases
to pass over, the receiver is changed and the distillation continued
until 45 per cent of oily distillate has been collected. The receiver
is again changed, and heavy oils containing paraffin wax, totalling
about 30 per cent by weight of the tar, are caught separately,
leaving 15 to 20 per cent of peat-tar pitch in the retort, which is
finally drawn off. The oily distillate first obtained is redistilled
into light naphtha (density under 0.83), and heavy naphtha (den-
sity 0.85). The heavy oil is cooled and pressed to separate lubri-
cating oil from the paraffin wax. The products are treated first
with concentrated sulfuric acid and then with caustic soda to re-
move tarry impurities and creosote oil respectively, the latter being
recovered in the form of creosote or carbolic acid.
The dry peat tar yields the following :

Crude,
Per Cent

After Purification,
Per Cent

Light naphtha

Heavy naphtha

Lubricating oil

o^
1C

1 O

Paraffin wax

1 j
12

X 3

Peat-tar pitch

Creosote

frt

Loss

1 1

100

A diagrammatical outline of the various products obtained on
the dry-distillation of peat is given in Table XX.

TABLE XX

PEAT

(Dry distilled)

Gas (57%)

Aqueous liquor (46%)
Distilled:

Peat tar (4%)
Distilled:

Coke (ag%)

1 i
Wood Ammonia
alcohol (o.i6%>
(0,34%)

i i i

Acetic Losses and Light
acid water oil
(0.44%) (%)

1 I
Heavy Paraffin
oU (0.3%)

1 1
Phen- Pitch
olatc (0.2%)

310 PEAT AND LIGNITE TARS AND PITCHES XV

Properties of Peat Tar. Dehydrated peat tars in general, test
as follows:

(Test i) Color in mass Black

(Test 7) Specific gravity at 77 F 0.90-1 .05

(Test 9) Hardness or consistency Liquid

(Test i fa) Fusing-point (K. and S. method) 40-60 F.

(Test 16) Volatile matter at 500 F., in 5 hrs 50-85 per cent

(Test 17*) Flash-point 60-95 F.

(Test 19) Fixed carbon 5-15 per cent

(Test at) Soluble in carbon disulfide 98-100 per cent

Non-mineral matter insoluble o- 2 per cent

Mineral matter o- i per cent

(Test 22) Carbenes o- 2 per cent

(Test 23) Solubility in 88 petroleum naphtha 95-100 per cent

(Test 28) Sulfur Less than i per cent

(Test 30) Oxygen in non-mineral matter 5-15 per cent

(Test 33) Solid paraffins 5-15 per cent

(Test 34^) Sulfonation residue 5-15 per cent

(Test 37*) Saponifiable constituents 5-15 per cent

(Test 39) Diazo reaction Yes

(Test 40) Anthraquinone reaction No

(Test 41) Liebermann-S torch reaction No

Properties of Peat-tar Pitch. Peat-tar pitch is obtained by the
evaporation or steam distillation of peat tar. It is not an article
of commerce in the United States. Its hardness or consistency,
as well as its f using-point, depend upon the extent to which the dis-
tillation has been conducted. Ordinarily, peat-tar pitch tests much
the same as lignite-tar pitch, the results being included in Table
LXXXIV. It is highly susceptible to temperature changes, and
withstands exposure to the weather very poorly.

LIGNITE TAR AND LIGNITE-TAR PITCH *

Varieties of Lignite. The U. S. Geological Survey estimates
that 1,087,514,400,000 tons of lignite are available in the United
States, but it is used only in a limited way, due to the abundance
of other types of fuel. Large deposits occur also in Alberta, Sas-
katchewan and Manitoba, Canada. A zone covering about 1700
square miles has been located in Australia, and one small deposit
has been reported in England (at Bovey-Tracey in Devonshire).
In Germany, however, the lignite industry has made much more
rapid advances, owing partly to the scarcity of high-grade coals, and
partly to the fact that the deposits are located close to large cities,

XV LIGNITE TAR AND UGN1TE-TAR PITCH 311

making the cost of transportation low. The lignite is accordingly
used as a fuel for steam plants f for manufacturing producer gas,
and for distillation purposes to recover its valuable by-products.
The descriptions of the methods which follow are based on

German practice as carried out in the following localities, viz. :

1 i ) Near Horrem, a short distance west of Cologne in Rhine Prov-

ince;

(2) In the neighborhood of Halle on the Saale, in the Proyinces

of Saxony and Thuringia; and

(3) At Messel, near Darmstadt in Hessen Province.

The so-called browncoal (variety of lignite) is mined at the first
two localities. It is estimated that 20,000 to 25,000 tons are bri-
quetted daily in the Cologne mining district alone, where the beds
run from 30 to 350 ft. thick, averaging 75 ft; Browncoal differs
somewhat from American lignite in carrying a higher percentage
of moisture (about 60 per cent instead of 25 to 50 per cent).
American lignites generally resemble bituminous coal in hardness
and appearance, whereas browncoal is distinctly earthy in appearance
and is soft and friable enough to be dug with a spade. Moreover,
browncoal contains up to 13 per cent waxy constituents which are
of great value as a binder in briquetting, whereas American lignites
contain less than 1.5 per cent of binder, and are unsuitable for
briquetting when used alone. As mined, browncoal is soft and either
unconsolidated or but slightly consolidated. The Messel deposit
carries about 30 per cent clay and 45 per cent water, the organic
constituents apparently being combined chemically with the clay.
It is greasy in consistency, having a black color with a greenish cast.
The bed covers about 240 acres in hemispherical depression, and
measures 480 ft. in thickness, under a cover 13 ft. thick composed
of gravel and clay.

Mining Methods. Browncoal in the Cologne and Halle re-
gions is found in stratified beds in which the layers alternately ap-
pear lighter and darker in color. The lighter layers form a
brownish-black plastic and greasy mass when freshly mined, and a
yellowish to light brown pulverulent substance when dry. They are
characterized by the presence of waxy constituents (soluble in car-
bon disuifide, benzol, etc.) The darker layers form a black plastic

312 PEAT AND LIGNITE TA&S AND PITCHES XV

mass when fresh, and a dark-brown to black earthy substance after
drying. They differ from the light-colored layers, in being sub-
stantially free from waxy constituents. The two varieties are
sorted during the process of mining. The light-colored product
resembles the mineral pyropissite.

The lighted variety of lignite has been incorrectly termed
"bituminous lignite," and the darker, "non-bituminous lignite." For
purposes of differentiation, we will refer to them as "retort lignite"
and "fuel lignite" respectively.* Retort lignite ranges in specific
gravity from 0.9 to i.i and melts at ignition, whereas fuel lignite
has a gravity of 1.2 to 1.4, and does not melt,

It is assumed that these two varieties of lignite, since they occur
in the same deposit, result from differing conditions surrounding
their formation, as for example a variation in water level. Thus
if the original vegetable matter containing a large amount of waxy
constituents was protected from the action of atmospheric oxygen
by being surrounded with vfater until the transformation into lignite
had been completed, then the woody tissue was more or less pre-
served, and fuel lignite resulted. If, however, the water receded
and exposed the deposit to the action of air, then the woody tissue
became partly or wholly oxidized, leaving the more resistant ma-
terials behind, and resulting in the formation of retort lignite. If the
process of atmospheric oxidation had been carried to the greatest
pdssible extent, then the waxes only remain behind, in the form of
the mineral pyropissite, which, however, is no longer mined, since its
total available supply has been exhausted. Lignite as freshly mined
is more or less rapidly acted upon by atmospheric oxygen, the dark
variety being more susceptible than the light one. A typical lignite
vein carries about twice as much fuel lignite as retort lignite.

Lignite is mined by the open-cut method where the over-burden
is not very thick, or by driving shafts and tunnels when the bed is
situated sortie distance below the surface. In the case of open-cut
mJfiirig, the overburden is first removed with steam shovels, and the
ligijite excavated by mechanically operated chain and buckets, which
load the material into small skips.

la Gerpany they are termed "Distillation Coal 1 ' (SchwelkoUe) and "Fire Coal"

XV LIGNITE TAR AND LIGNITE-TAR PITCH 313

Shaft mining presents a number of difficulties owing to the soft-
ness and unstability of the crude lignite. The shafts must be well
timbered, and in many cases it is first necessary to freeze the lignite
before it can be handled.

Methods of Distilling. Retort lignite is treated in one of two
ways, viz. :

(1) It is subjected directly to low-temperature destructive dis-
tillation 6 or

(2) It is first extracted with a solvent to remove the montan
wax and the residue either distilled destructively or briquetted and
sold as fuel.

Fuel lignite is also treated in one of two ways, viz. :

(1) If it is comparatively free from ash, it is briquetted and
used as fuel ; or

(2) If it contains a large proportion of ash, as with Messel
lignite, it is used for manufacturing producer gas by combustion in
an atmosphere of air and steam, so that practically all the carbon-
aceous matter is consumed, leaving almost pure ash behind. Smce
Messel lignite in its crude state contains but 25 per cent of com-
bustible material, it is unsuitable for use as fuel, or for purposes
of destructive distillation.

When the lignite is to be used for fuel, it is converted into
briquettes by subjecting the granulated material to great pressure.
The heat generated during this operation softens the waxy sub-
stances present, and binds the particles into a solid mass. It is
unnecessary, therefore, to add any extraneous binding medium.

In manufacturing briquettes, the lignite is first crushed to about
the size of peas, then passed through a drier to reduce the moisture
to approximately 15 per cent. A tubular drier, heated with steam,
has been found most satisfactory for the purpose. 6 The lignite
powder is fed into a briquetting press, where it is subjected to a
pressure between 18,000 and 22,500 Ib. per square inch.

Retort lignite is unsuitable for fuel or manufacturing briquettes,
as the large quantity of waxy constituents present will soften when
heated, causing the briquettes to melt and drop through the grate

314

PEAT AND LIGNITE TARS AND PITCHES

bars. When the retort lignite has been extracted with solvents to
remove the "montan wax/' the residue retains enough waxy con-
stituents to enable it to be briquetted.

When the retort lignite is to be subjected to destructive distilla-
tion, it is used directly as
it comes from the mine,
without drying. In fact,
the presence of the water
materially assists the dis-
tillation process by pre-
venting the volatile prod-
ucts from decomposing
too extensively. The
water is converted into
steam which quickly re-
moves the vapors from
the hot retort and pre-
vents cracking, thus in-
creasing the yield of tar.
Taking the yield of tar
from freshly mined lignite
as loo, the yield from air-
dried lignite is about 74,
and from lignite dried at
105 C. approximately 56-.
Practice has shown
that the moisture content
should not be less than 30
per cent. In distilling lig-
nite, the humic acids pres-
ent are converted into the

so-called "neutral bodies," the cellulose derivatives into phenolic
bodies and unsaturated hydrocarbons, and the waxy constituents into
saturated hydrocarbons and paraffin wax.

It is claimed that the Rolle retort shown diagrammatically in
Fig, 96 has been found most satisfactory for treating 3-5 tons lignite
per day. It is 5 to 6 ft* in diameter by 20 to 25 ft. high, and works
continuously, the operation progressing in two stages, viz.:

FIG. 96. Retort for Distilling Lignite.

XV LIGNITE TAR AND UGNITE-TAR PITCH 315

1 i ) Drying the lignite.

(2) Decomposing the lignite into gas, water, tar and coke.

The contrivance is composed essentially of two concentric cylin-
ders, an outer one of fire brick and an inner one consisting of a stack
of conical rings assembled in louvre fashion, constructed of iron or
fire clay. The lignite after being crushed into lumps about i l /2, to
2 l /2 in. in diameter is introduced into the space between the con-
centric cylinders. The products of distillation pass out through the
flues A and B. The openings C represent the fire-flues; D ; the
stack of conical rings; E, the cap covering the rings; F, an inverted
cone of metal into which the coke falls after the lignite has been
thoroughly carbonized; G, a device for intermittently drawing off
the coke ; H, the combustion chamber ; /, vents for introducing the
gases; K y the pipes through which the gases enter; and L, the fire
place which comes into play when the retort is first started up. Coal
or lignite is burnt on the grate, until the process of destructive dis-
tillation commences, whereupon the resulting non-condensable gases
are introduced through K and /, and caused to burn in the flues C.
The space over the cap E is kept filled with lignite, and the rate of
travel through the retort is controlled by the frequency with which
the coke is removed from the chamber G.

The temperature at which the distillation takes place varies
between 500 and 900 F., and the vapors issue from the retort at
250 to 300 F. The products of decomposition are drawn from the
retort by a slight suction, and passed through a series of air con-
densers, which removes most of the tar, the high boiling-point oils,
and part of the water. The condensation is completed by passing
the gases through pipes surrounded by water.

The tar is separated from the condensed water by warming it
and allowing it to stand quietly in a suitable receptacle. The tar
being lighter than the water, rises to the surface, and is drawn off
when the separation is complete.

Products Obtained. A bituminous lignite containing 20-30 per
cent moisture and 15-16 per cent soluble in carbon disulfide,
yielded 24 per cent tar having a specific gravity of 0.885 at 50 C.,
a solidifying point of 37 C., and containing 16 per cent creosote
oils. Similarly, a non-bituminous lignite containing 15 per cent

316

PEAT AND LIGNITE TARS AND PITCHES

moisture and 3-4 per cent soluble in carbon disulfide, yielded 7.6
per cent tar having a specific gravity of 0.955 at 5 C., a solidi-
fying point 33 C, and containing 37 per cent creosote oils. On
fractional distillation with superheated steam, the former yielded
3.2 per cent pitch and the latter 8.5 per cent
The following yields are obtained :

Lignite tar (vertical retorts) up to 7 per cent

" " (low temperature) 7 to 12 per cent

Brown-coal tar (Rolle retort) 4 to 8 per cent

" " " (low-temperature) 8 to 24 per cent

A commercial product known as "kaumazite" is made from
Bohemian lignite by a process of low-temperature distillation.

In recent years the following
products have been recovered :

Water 50-60 per cent

Tar 5-10 per cent

Coke 25-35 per cent

Gas Balance

Treating Impure Lignite. The
Messel lignite carrying a large per-
centage of mineral matter is treated
in a special form of retort built in
batteries, as illustrated in Fig, 97,
The process takes place in three
stages, viz. :

1 i ) Drying of the lignite and ac-
companying generation of steam, tak-
ing place in the zones c.

(2) Distillation of the dried ma-
terial, taking place in zones b.

(3) Combustion of the residual
coke by means of air and the steam
generated in (i), taking place in
zones a. The steam liberated in
zones c is passed through the flues
G-tf, /-/, and G-^ ; respectively, into
zones a j as illustrated.

Fie. 97. Retort for Distilling
Impure Lignite.

In other words, the steam generated by the lignite itself, is used
to decompose the coke into producer gas, The gas is caused to burn

XV LIGNITE TAR AND LIGNITE-TAR PITCH 317

in the chambers A, B and C respectively, the products of combus-
tion passing through the openings o ) o. Pipe d represents the out-
let for the products of decomposition, and s represents the supply
pipe for the heated gas. The paths of the products are indicated by
the arrows. The yield of tar varies between 4 and 14 per cent,
averaging about ^ l / 2 per cent (19 gallons per ton), that of gas 6
per cent, water 44 per cent and coke 36 per cent. The residue dis-
charged from the bottom of the retort is composed of mineral mat-
ter carrying 8 per cent of undecomposed carbon. More gas is gen-
erated during the process than is required for heating the retort,
hence the excess is used for other purposes.

Lignite in either the air-dried or briquetted form is gradually
being used more and more, especially in Europe, for manufacturing
producer gas. About 60 cu. ft. of gas are produced from each
pound of the dry lignite, also l / to l / 2 per cent by weight of lignite
tar, which is separated from the producer gas in the usual manner.

In certain localities (e. g. northern Bohemia) lignite is carbon-
ized in a variety of coke-oven, similar to that used for treating
coal, to produce coke, during which process a tar is obtained known
as coke-oven lignite-tar. The carbonization takes place at 1100 C.
and the resulting tar has a specific gravity at 60 C. of 0.970.

Properties of Lignite Tar. Lignite tar has a buttery consist-
ency at ordinary temperatures and a dark brown to black color. It
is composed of liquid and solid members of the paraffin and olefine
series, together with a small quantity of the benzol series, also the
higher phenols and their derivatives ( fo to 25 per cent) . It is char-
acterized by the presence of a substantial proportion of solid paraf-
fin (10 to 25 per cent) and from 0.5 to 1.5 per cent of sulfur.

Four different varieties of lignite tar are recognized, viz. :

(i) Retort tar (e. g. from Rolle retorts).

(2} Low-temperature lignite-tar (produced below 6po C.),

) Producer-gas lignite-tar (e. g. from Messel lignite).

) Coke-oven lignite-tar (e. g. northern Bohemia).

Lignite tars are usually emulsified with water, which separates
with difficulty, and when derived from gas-producers they carry a
certain amount of free carbon (up to 3 per cent). Both may be
removed by centrifuging. Thus a tar carrying 1 1.7 per cent water
and 2.28 per cent free carbon, upon centrifuging at 4000 to 6000

318 PEAT AND LIGNITE TARS AND PITCHES XV

r,p.m. at 60-85 C., yielded a product carrying 0.7 per cent water
and 0.06 per cent free carbon.

In general, dehydrated lignite tar conforms with the following
characteristics :

(Test i) Color in mass Yellowish brown to

greenish brown to
brownish black

(Test 7) Specific gravity at 77 F o. 85-1 ,05

(Test 9) Hardness or consistency at 77 F Salve-like to buttery

(Test 10) Ductility at 77 F None

(Test 150) Fusing-point (K. and S. method) 60-90 F.

(Test 15^) Fusing-point (R. and B. method) 75-100 F.

(Test 1 6) Volatile matter at 500 F., 5 hrs 70-85 per cent

(Test 170) Flash-point (Pensky-Martens tester) 7 5-90 F.

(Test 19) Fixed carbon 5-20 per cent

(Test 200) Distillation test The boiling-point ranges

between 80 and 400
C., the greater por-
tion distilling between
250 and 350 C

(Test 2i) Soluble in carbon disulphide 96-100 per cent

Non-mineral matter insoluble o- a per cent

Mineral matter o- i per cent

(Test 22) Carbenes o- 2 per cent

(Test 23) Solubility in 88 petroleum naphtha 98-100 per cent

(Test 28) Sulfur o. 5-2 . 5 per cent

(Test 29) Nitrogen Less than o. i per cent

(Test 30) Oxygen 5-10 per cent

(Test 31) Free carbon o-i per cent

(Test 32) Naphthalene -1 per cent

(Test 33) Solid paraffins 10-25 per cent

(Test 34^) Sulfonation residue 10-20 per cent

(Test 37*) Saponifiable constituents 5-20 per cent

(Test 39) Diazo reaction Yes

(Test 40) Anthraquinone reaction No

(Test 41) Liebermann-S torch reaction No

Marcusson and Picard 7 have reported the following percent-
ages of saponifiable constituents present in normal tar from Saxon-
Thuringian lignite : saponifiable constituents 7.4 per cent, consisting
of oxy-acids soluble in ether 2.4 per cent; reported as fatty acids
3,0 per cent; and phenols 2.0 per cent Generator tar from Saxon-
Thuringian lignite: saponifiable constituents 14.0 per cent, com-
posed of oxy-acids soluble in ether 0.5 per cent; oxy-acids insoluble
in ether 4.0 per cent; reported as fatty acids 4.5 per cent; and
phenols 5.0 per cent.

Refining Processes. In practice, lignite tar is distilled to sep-
arate various oils and paraffin wax. The distillates are purified by

XV LIGNITE TAR AND LIGNITE-TAR PITCH 319

treatment with acids and alkali, and the paraffin by re-crystalliz-
ation.

The distillation is conducted in one of three ways, viz. :

1 i ) At atmospheric pressure, without steam.

(2 ) By means of steam, sometimes after treating with alkal

(3) Under vacuum, sometimes supplemented with steam.

Vacuum distillation is generally used, as it saves fuel, reduces
the time and prevents cracking of the distillates. The best prac-
tice consists in using a slight vacuum at the beginning of the distilla-
tion, and gradually increasing it until the paraffin begins to distil,
when it is maintained at 1 6 to 28 in. of mercury by a steam injector,
or vacuum pump.

With steam distillation, either plain or superheated steam may
be used and direct heating of the retort may be dispensed with in
the latter case.

The distillation may be intermittent or continuous. European
practice provides for the continuous distillation of the dehydrated
tar in a battery of vertical cylindrical stills with hemispherical bot-
toms, having dome-shaped tops. Each still is connected with a con-
denser composed of a circular coil of metal piping immersed in a
water tank. Between 10 and 20 stills are erected side by side on a
common brick setting.

Lignite tar is first distilled to % its original bulk, and the com-
bined residues of several stills are run into a separate retort. In
some cases the residues are distilled to produce lignite-tar pitch, but
in the majority they are distilled until nothing but coke remains.
By thus treating the residues in separate retorts, the lives of the first
retorts are lengthened materially, and the wear and tear concen-
trated on a few. The retorts in which the preliminary distillation
takes place are of course subjected to a much lower temperature
than those in which the residues are treated.

When lignite tar is distilled to coke, a certain amount of crack-
ing occurs and consequent formation of tarry matter in the distill-
ates, which is removed by treating with sulfuric acid. The result-
ing sludge is worked up into lignite-tar pitch as will be described
later.

Obviously the pitches derived in these two ways differ in their

320 PEAT AND LIGNITE TARS AND PITCHES XV

physical properties, and particularly in the quantity of associated
paraffin, which is smaller in lignite-tar-sludge pitch.

Products Obtained. The tar is fractioned into crude oil (about
33 per cent), a paraffinaceous distillate (about 60 per cent), red
oil (about 3 per cent), and yields permanent gases (about 2 per
cent), and coke (about 2 per cent).

The crude oil is re-distilled into naphtha, illuminating oil, clean-
ing oil, gas oil and light paraffin oil (vaseline oil). The paraffin-
aceous mass is cooled and pressed, which removes the heavy paraf-
fin oil from the paraffin wax. The paraffin wax is then re-crystal-
lized and separated into the soft paraffin wax and hard paraffin
wax respectively.

According to Waldemar Scheithauer, an average grade of lig-
nite tar will yield the following products, viz. : benzine 5 per cent,
lubricating oil 5 to 10 per cent, light paraffin* oils 10 per cent,
heavy paraffin oils 30 to 50 per cent, hard paraffin 10 to 15 per cent,
soft paraffin 3 to 6 per cent, dark-colored products 3 to 5 per cent/
coke, gas and water 20 to 30 per cent. If the distillation of lignite
tar is not continued to coke, lignite-tar pitch is obtained, amounting
to about 5 per cent by weight of the tar.

The diagram in Table XXI shows the essential steps in treating
lignite tar by fractional distillation, including the two alternatives of
running to pitch and coke respectively.

The fractions are purified by treating successively with weak and
strong sulfuric acid, followed by caustic soda, which improve the
color and odor, and enable the products to command a higher price.
The preliminary treatment with weak sulfuric acid removes a por-
tion of the basic constituents, including the pyridirie. The stronger
sulfuric acid extracts the remaining basic substances, the tarry mat-
ters which impart a dark color, a portion of the unsaturated hydro-
carbons and the resinous constituents. The alkali serves to neu-
tralize the acid, and to remove the creosote oils which would impart
a disagreeable odor and darken on exposure to light

After the chemical treatment, the acid and soda sludges are
settled off. The acid sludge is boiled with steam in lead-lined ves-
sels, which decomposes it into pitch and sulfuric acid (30 to 40
Baume). This acid is used for decomposing the soda sludge into
creosote oil and sodium sulfate (Glauber salt). The impure creo-

LIGNITE TAR AND LIGNITE-TAR PITCH

321

||H
1

^s
o

322 PEAT AND LIGNITE TARS AND PITCHES XV

sote containing tarry matters is mixed with the pitch separated from
the acid sludge, and after washing with water to remove all traces
of acid and alkali, the mixture is distilled with superheated steam.
The purified lignite creosote is recovered as distillate (having a
specific gravity of 0.940 to 0,980, and yielding 50 to 70 per cent
soluble in caustic soda) and the lignite-tar pitch remains as residue.
The extent to which the distillation is continued regulates the hard-
ness and fusing-point of the pitch, which is much harder in consist-
ency than that obtained from the direct distillation of lignite tar.
A black, glossy pitch of good quality may be produced by treating
lignite tar with 4 per cent sulfuric acid (60 Baume) at 160 C.
and the lower pitch-like layer heated with 20 per cent anthracene
oil at 250 C. 9

Properties of Lignite-tar Pitch. Lignite-tar pitches conform
with the following tests :

(Test i) Color in mass Hack

(Test 2) Homogeneity. Uniform

(Test 3) Appearance surface aged indoors one week. . Dull

(Test 4) Fracture Conchoidal

(Test 5) Lustre Very bright when fresh

(Test 6) Streak Black

(Test 7) Specific gravity at 77 F i .05-1 . 20

(Test 9^) Penetration at 77 F 0-60

(Test 9f) Hardness at 77 F., consistometer 10-100

(Test gd) Susceptibility index Greater than too

(Test 10) Ductility Variable

(Test 150) Fusing-point (K. and S. method) 90-250 F.

(Test 15^) Fusing-point (R. and B. method) 100-275 F.

(Test 16) Volatile matter Variable

(Test ija) Flash-point Usually above 250 F.

(Test 19) Fixed carbon 10-40 per cent

(Test 21) Solubility in carbon disulfide 95-99 per cent

Non-mineral matter insoluble * 0-2 per cent

Mineral matter o- i per cent

(Test 22) Carbenes 0-5 per cent

(Test 23) Solubility in 88 petroleum naphtha. ..... 60-85 per cent

(Test 25) Solubility in benzol 75-90 per cent

(Test 28) Sulfur i . 5-2. 5 per cent

(Test 30) Oxygen in non-mineral matter 2- 5 per cent

(Test 31) Free carbon Trace

(Test 32) Naphthalene Absent

(Test 33) Solid paraffins i- 5 per cent

(Test 34^) Sulfonation residue 5-15 per cent

(Test 37*) Saponifiable constituents o- 8 per cent

(Test 39) Diazo reaction Yes

(Test 40) Anthraquinone reaction No

(Test 41) Liebermann-Storch reaction No

XV LIGNITE TAR AND LIGNITE-TAR PITCH 323

The following figures are reported by Julius Marcusson : 10

(Test 9) Hardness

STRAIGHT-
DISTILLED
LIGNITE-TAR
PITCH

. . . . . M oderatelv hard

LIGNITE-TAR
PITCH
DERIVED FROM
ACID-SLUDGE

Hard and brittle
i 9 oi F.
20 per cent
> 2 per cent
4-4
13-4
6.0 per cent
36 per cent
8 per cent
26 per cent

(Test 150) Fusing-point (K. and S. method)88 F.
(Test 24) Free carbon , * . , . - 1 1 t5*r cent

(Test 28) Sulfur

< 2 per cent

(Test 374) Acid value

o, c

(Test 37^) Saponification value . .

2.8

(Test 37^) Saponifiable constituem
(Test 38^) Asphaltenes

ts .... 1.8 per cent

24 per cent

(Test 38^) Asphaltic resins

ii per cent

(Test 38*) Oily constituents*. . . .

48 per cent

* Salve-like;

light brown color.

Soft lignite-tar pitch is almost completely soluble in benzol and
turpentine, and less soluble in petroleum benzine or naphtha. The
solubility of hard pitches decreases in proportion to the extent they
have been distilled. Lignite-tar pitch derived from acid sludge may
be distinguished from straight-distilled pitches by the presence of
sulf uric-acid oxonium derivatives insoluble in 88 petroleum naph-
tha, as is the case with sludge asphalts derived from petroleum. Lig-
nite-tar pitches are distinguished from coal-tar pitches by the ab-
sence of anthracene, the presence of small quantities of paraffin wax,
and the formation of water-insoluble sulfo-derivatives upon treat-
ment with concentrated sulf uric acid (whereas coal-tar pitches form
soluble derivatives). Furthermore, the free-carbon separated
from lignite-tar pitches differs from that obtained from coal-tar
pitches by the fact that the former is completely converted into
soluble nitro-derivatives upon heating with fuming nitric acid. Lig-
nite-tar pitches are distingished from wood-tar pitches by the asso-
ciated sulfur and paraffin wax; also from asphalts, rosin pitch and
fatty-acid pitch by the diazo reaction. 11

A process of blowing lignite tar with air in, the presence of
mineral substances has been patented. 12 It has also been proposed
to blow a mixture of lignite-tar pitch and refined Trinidad asphalt. 18
Lignite tars may be hardened by heating with sulfur, 14 or by heat-
ing with spent iron oxide containing sulfur (obtained in the puri-
fication of coal gas) in the presence of FeQ 3 , MnSO 4 , or the like. 18
In Germany, where practically all of the lignite-tar pitch is pro-
duced, it is used extensively for manufacturing cheap paints.

CHAPTER XVI
SHALE TAR AND SHALE-TAR PITCH

Shale Mining. Scotland is the home of the "shale oil" indus-
try. The present chapter is based on the operations practiced in
Scotland, since in other countries the treatment of shales has not
been developed to what may be regarded as an industry scale. In
the United States, for example, the distillation of shales is more
or less in a process of development, and at the present writing is
still in an experimental stage.

At the present time, Scotch refineries are located at Pumphers-
ton, Broxburn, Oakbank, Addiewell and Uphall ; crude-oil works at
Addiewell, Broxburn, Dalmeny, Deans, Hopetoun, Niddry Castle,
Oakbank, Philipstoun, Pumpherston, Roman Camp, Seafield, Tar-
brax and Uphall; and candle works at Addiewell and Broxburn.

Shale is mined in the same manner as bituminous coal, by driving
shafts, and then extending drifts radially. Considerable timbering
is necessary, on account of the softness of the shale. When the
seams are over 4 ft. in thickness, they are mined by the "pillar-and-
stall" method, and when less than 4 ft. thick, by the "longwall"
method.

The mineral as mined is hauled to the surface by power, and
then run through a breaker, where the masses are broken into lumps
measuring 4 to 6 in. in diameter. The breakers consist of a number
of toothed iron discs mounted on two shafts revolving in opposite
directions. The shale, upon being crushed to the proper size, is next
conveyed up an iacline to the top of the retort.

Retorts Used for Distillation. The retorts used have been modi-
fied from time to time to increase their efficiency, add to their dura-
bility, hasten the speed of treatment, or to improve the quality of
the output. In all instances the distillation takes place in the upper
part of the retort where the shale is heated to 900 F. It is then
subjected to a higher temperature (1300 to 1800 F.) in the lower
portion, which is in reality a gas producer, steam and air being

824

XVI

SHALE DISTILLATION

325

admitted to convert the carbonaceous residue into carbon dioxide
and carbon monoxide. This generates sufficient heat to effect the
distillation in the upper portion of the retort. The admission of air
is carefully regulated to maintain the required temperature, with-
out causing excessive combustion of the by-products. The steam
serves to convert the nitrogen into ammonia, increases the value of
the shale tar, dilutes the gas vapors, increases the velocity of the
discharge, reduces the secondary decomposition of the vapors, in-
creases the yield of paraffin products, and equalizes the temperature.

' 1 '

FIG. 98. ^View of Pumpherston Works, Showing Mine-head, Retorts and Refinery.

The charge gradually passes downward in the retort at a speed
regulated by the removal of the spent shale at the bottom.

At present, the tendency seems to gravitate towards the use of
two types of retorts, viz.: the Pumpherston and the Henderson
retorts, of which the former is considered to be the more efficient.
Both types will now be described.

Pumpherston Retort. A view of the Pumpherston works,
showing the retorts and refinery is given in Fig. 98. A bank of the
retorts is illustrated in Fig. 99, and the equipment for condensing
the oils and ammoniacal liquors from the gases emanating from the
retorts is shown in Fig. 100. Similarly, a cross-section of a Pum-
pherston retort is given in Fig. 101. The shale is prevented from

326

SHALE TAR AND SHALE-TAR PITCH

XVI

Fia 99. Bank of Scottish Shale Retorts (Pumpherston Type).

FIG. loo. Plant for Condensing Shale Tar and Ammonia Water Emanating from the

Shale.

XVI

SHALE DISTILLATION

fluxing and choking up the retort
by keeping it moving continuously,
which is accomplished by support-
ing the column of shale on a disc
e, from which a revolving scraper
/ discharges the spent shale into
the hopper below. The shale is
introduced into an iron-charging
hopper c, whence it passes into
the upper cylindrical cast-iron por-
tion of the retort a, measuring
1 1 ft. high, 2 ft. in diameter at
the top and 2 ft. 4 in. at the bot-
tom. In this, the actual distilla-
tion takes place at 900 F., with
the formation of oil and gas. The
shale slowly works its way into
the lower portion b constructed
of firebrick, of circular cross-sec-
tion, measuring 20 ft in height
and enlarged at the bottom to 3
ft. in diameter, and finally into
the lower hopper d extending un-
derneath several retorts, converg-
ing in such a manner that a single
line of rails running below the
center will permit the spent shale
to discharge into small cars.
Steam is introduced into the
lower portion of the retort, a
short distance above the disc e,
and the gaseous products of dis-
tillation are burned with air in the
external flues at 1800 F. in the
zone b where the ammonia is
formed. The daily capacity of
the retort is 4 to 4^4 tons, de-
pending upon the richness of the
shale. Four retorts constitute an

FIG. 101. Pumpherston Type of Retort
for Distilling Shale.

828

SHALE TAR AND SHALE-TAR PITCH

XVI

FIG. 102. Broxburn Type of Retort for Distilling Shale*

XVI METHODS OF RECOVERING SHALE TAR 329

"oven," and 16 ovens a "bench.* 1 The maximum output of shale
oil amounts to 96 gal. per retort per day under the best operating
conditions.

Henderson or Broxburn Retort. This is illustrated in Fig. 102,
and consists of iron hoppers a on top, into which the crushed shale
is fed, next a rectangular cast-iron section b measuring 2 f t. 9 1 /2 in*
by i f t 2 y% in. at the top, and 3 ft J4 * n - by I f t. 5 % in. at the
bottom. This is 14 ft. long, and is joined by a fire-clay joint to a
fire-brick section c, 20 ft. long, of rectangular cross-section, measur-
ing 4 ft. 8 in. by i ft. 10 in. at the bottom. A pair of toothed iron
rollers d continuously discharge the spent shale from the bottom
into hoppers e, which are periodically emptied into cars under-
neath. The vapors pass out at the top through the ducts /, into
headers g. A slight vacuum is maintained in the retort and steam
is admitted into the bottom of the fire-brick portion. The tempera-
ture reaches 900 F. in the upper cast-iron section, where practically
all the oil is distilled, and the shale is subjected to an increasing
temperature, reaching a maximum of 1500 F, at the lower portion
of the fire-brick section, whereupon it is cooled by the incoming
steam before it is discharged. The retorts are heated by the fixed
gases evolved from the shale, supplanted by a proportion of pro-
ducer gas. The arrangement of the retorts in benches and ovens,
also the output, is the same for the Pumpherston type. 1

Methods of Recovering Shale Tar. The vapors which leave the
retorts are passed through air-cooled pipes (Fig. 100) which sep-
arate most of the tar and ammoniacal liquor. Sometimes an econ-
omizer is used, consisting of a tower filler with pipes, around which
cold water is circulated, and thus preheated for use in the steam
plant The vapors are next passed through a scrubber (filled with
coke or a checker-work of wood), and finally through a naphtha
scrubber where they are washed with the " intermediate oil" ob-
tained in distilling the shale tar (having a high boiling-point and
a specific gravity of 0.84 to 0.86) which extracts any light naphtha
not previously condensed (about 2 gal. per ton of shale). The
naphtha is separated from the scrubbing oil by heating the mixture
moderately in a still, and condensing the distillate (having a specific
gravity of 0.73)*

380 SHALE TAR AND SHALE-TAR PITCH XVI

The crude tar and ammoniacal liquor are allowed to flow from
the condensers to separating tanks, where upon standing, the tar
rises to the surface and is drawn off and piped to the refinery* The
crude tar is generally termed "shale oil/' but this name is just as
inappropriate as the expression "oil shale," often used to designate
the shale*

Products Obtained. Upon destructively distilling the Kim-
meridge Shales of England and the Lothian Shales of Scotland,
the following products are obtained :

(1) Non-condensable gases, averaging 9800 cu. ft per ton
(2000 Ib.).

( 2 ) Ammoniacal liquor yielding an average of 40 Ib. ammonium
sulfate per ton.

(3) Shale tar, Averaging 22 gal. per ton.

(4) Scrubber naphtha, averaging 0.4 gal. per ton.

(5) Spent shale, averaging between 75 and 85 per cent of the
raw shale (i.e., 1500 to 1600 Ib. per ton), and containing approxi-
mately 2j^ per cent unconsumed carbon.

The non-condensable gases are burned under the retorts, and
the spent shale discarded, as it has no further value. The valuable
products are the light naphtha, the shale tar and ammonium
sulfate.

The ammoniacal liquor separated from the tar is treated with
steam under a pressure of 20 to 30 Ib. in a tower filled with baffle-
plates. The liquor is run in at the top and the steam introduced at
the bottom. The ammonia is expelled in the gaseous state and re-
covered by passing it into sulfuric acid contained in a vessel known
as a "cracker box." The acid used for this purpose is usually the
waste product from the refining process. Crystals of ammonium
sulfate separate when the liquor becomes sufficiently concentrated,
and after being dried are marketed as such. In this manner the
ammonia is separated from the other nitrogenous bases, including
pyridine, contained in the aqueous liquor.

The following table gives the minimum and the maximum
yields of dehydrated shale tar in gallons, and ammonium sulfate in
pounds per ton of shale, obtained from the most important shate
deposits in different parts of the world, 2

XVI

PROPERTIES OF SHALE TAR

331

Yield of Shale Tar
(Gallons)

Yield of Ammonium
Sulfate (Pounds)

Lothian shale (Scotland)

Kimmeridge shale (England)

Coorongitic shale (New South Wales) .

Orepuki shale (New Zealand)

Albert shale (New Brunswick)

Arcadian shale (Nova Scotia)

Shales (Eastern United States)

Utah shales

Colorado and Wyoming shales

Kukkersite (Esthonia)

ro-55

10-40

14-150

20-40

30-51

4-45

6-10

10-68

70-80

6-70
10-50
20-30

67-1 1 1
9-40
o-io

40-50

22-34

5-15

Properties of Shale Tar. Shale tar usually appears black in mass
with a greenish fluorescence. It is similar in composition to lignite
tar, although differing from the latter in containing a larger per-
centage of nitrogen (i.i to 1.5 per cent). -Members of the paraf-
fin and olefine series constitute 80 to 90 per cent by weight of the
tar, and small quantities of cresols and phenols are present

Dehydrated shale tar tests as follows:

(Test i) Color in mass , Brownish black with a

greenish fluorescence

(Test 7) Specific gravity at 77 F o. 85-0.95

(Test 9) Hardness or consistency Salve-like to buttery

(Test 150) Fusing-point (K. and S. method) 60-90 F.

(Test 15^) Fusing-point (R. and B. method) 75~n 5 F.

(Test 1 6) Volatile matter at 500 F., 5 hrs 80-90 per cent

(Test ija) Flash-point (Pensky-Martens tester) 20-60 F.

(Test 19) Fixed carbon 5-10 per cent

(Test 21) Soluble in carbon disulfide 98-100 per cent

Non-mineral matter insoluble 0-2 per cent

Mineral matter o-i per cent

(Test 22) Carbenes 0-2 per cent

(Test 23) Soluble in 88 petroleum naphtha 95-100 per cent

(Test 24) Free carbon 0-2 per cent

(Test 28) Sulfur i . 5-2. 5 per cent

(Test 29) Nitrogen o. 25-1 .o per cent

(Test 30) Oxygen 1-5 per cent

(Test 33) Solid paraffins 5-15 per cent

(Test 34^) Sulfonation residue I5~35 per cent

(Test 37?) Saponifiable constituents 0-2 per cent

(Test 39) Diazo reaction Yes

(Test 40) Anthraquinone reaction No

(Test 41) Liebermann-Storch reaction No

The percentage of phenols contained in the shale tar is very
much smaller proportionately than that present in peat or lignite

332 SHALE TAR AND SHALE-TAR PITCH XVI

tars. Shale tar is distinguished from the latter by containing larger
percentages of nitrogen and sulfur, and smaller percentages of
oxygen, paraffin and phenols respectively.

Refining of Shale Tar. Shale tar may be distilled either inter-
mittently or continuously. In either case the process consists in
heating the tar in a still to expel the moisture, whereupon either
plain or superheated stam is introduced through a perforated pipe
under a pressure of between 10 and 40 Ib. The tar is distilled to
coke and the following products separated:

1 i ) Non-condensable gases ranging from i to 2 cu. ft. for each
gallon of shale tar.

(2) Crude naphtha having a specific gravity of 0.74 to 0.76.

(3) So-called "crude distillate," or "once-run oil/' or "green
oil" representing the fraction between the crude naphtha and coke.

(4) A residue of coke approximating 3 per cent by weight of
the shale tar.

The steam is shut off towards the end of the distillation, after the
"once-run oil" has passed over.

The stills used in Scotland are of the vertical type from 2000 to
2500 gal. capacity, constructed of a hemispherical cast-iron bottom,
and a soft malleable-iron cylindrical body to which is attached a
dome-shaped top bearing the exit pipe. Each still is connected with
its own condenser.

In the continuous distillation process, termed the "Henderson
Process," a battery of three horizontal stills and one or more ver-
tical pot-stills are used. The tar is first led into the middle hori-
zontal still where the naphtha is distilled off, and the residue caused
to flow continuously into the two side stills. These are heated
higher than the center still, causing the one-run oil to distil over
continuously. The residues from these second stills are led into the
pot-still, where they are evaporated to dryness, the distillate being
condensed and united with the once-run oil. Several pot-stills are
used, since the red-hot coke must be allowed to cool before it can be
removed, which prevents this part of the process being continuous.

The once-run oil is refined by agitating it with sqlfuric acid at
100 F. by compressed air. The acid sludge is run off, the oil
washed with water, and then treated in another agitator with caus-
tic soda in a similar manner*

XVI REFINING OF SHALE TAR 333

The refined once-run oil is fractioned either by an intermittent
or continuous steam distillation process, the following products be-
ing recovered :

1 i ) Heavy naphtha varying in gravity between 0.75 and 0.77.

(2) ^ Illuminating oils varying in gravity between 0.78 and 0.85,
and having a flash-point of 125 F,

(3) Gas-oil and fuel-oils varying in gravity between 0.85 and
0.87, and having a flash-point higher than 150 F. These are used
as fuel, or for manufacturing water-gas, or enriching illuminating
gas.

(4) Lubricating oils having a gravity from 0.87 to 0.91.

(5) Paraffin wax which is purified by re-crystallization or
"sweating, 1 * having a fusing-point between 110 and 130 F.

(6) Still grease, which represents the distillate passing over at
the close of the distillation.

(7) Still coke, which remains in the still at the close of the
operation.

The various distillates, with the exception of the still grease are
refined further with sulfuric acid and caustic soda, similar to the
method used for treating the once-run oil. The crude paraffin wax
is refined by the sweating process.

The various steps of the distillation and refining processes are
illustrated in Table XXII.

The following yields are obtained from dehydrated Scotch shale
tar:

Heavy and light naphthas 3-6 per cent

Illuminating oil 20-30 per cent

Gas-oil or fuel-oil 10-25 per cent

Lubricating oil > 1 5-20 per cent

Soft paraffin scale 3-5 per cent

Hard paraffin wax 7-9 per cent

Non-condensable gases 3-5 per cent

Acid and soda sludges and losses t . . . 20-25 per cent

Still coke 2-3 per cent

The acid and soda tars obtained from the various refining
processes are mixed together in such proportions that the free acid
and alkali will exactly neutralize each other. The resulting sludge
is ordinarily used as fuel for the stills, but experiments have been
made to convert it into pitch suitable for use as a wood preserva-
tive, pipe-dip, or the base of bituminous paints. Comparatively

334

SHALE TAR AND SHALE-TAR PITCH

XVI

TABLE XXII

FLOW SHEET ILLUSTRATING THE METHOD OF MANUFACTURE OF OILS, PARAFFIN WAX AND
SULFATE OF AMMONIA FROM SHALE. THE NAMES OF FINISHED PRODUCTS ARE UNDER-
LINED

SHALE

Liq

Scrubber
Naphtha

Treated & Distd.

Shale
Tar

Shale

Swfate

otArrimoriia

Motor

3E#

Wed

Cfude
Naphtha

TreatedWisrd

Treated

t
IS

de Shale CoJ*
Hate Rasm

tOtstd.

Ctoaners*

So/Wf

Crbdc
Burning

HeavyOtl \
contain/no CoAe
Solid paraffin

la/no fbber Signal tJtoise Crude
~ "O/L M

Cooled, filtered 3 pressed

B/ue-Ofl

Treattd&Distd

J$$d
faMffin

Cooled, Filtered

Baiching Lao. Oil

OH&Sonet QSolid

Paraffin Paraffin'

Cooted,rtHer*d Cookd.fi fared
$

UMll Solid
VnM Paraffin

'" \ -'

Residuum
Oil

XVI REFINING OF SHALE TAR 335

little has been accomplished in this direction, probably due to the
fact that other products are available for these purposes, costing
but little more and possessing superior weather-resisting properties.
Shale-tar pitch is similar in its physical properties and composition
to lignite-tar pitch,

A residue derived from Esthonian shale oil (obtained by the
destructive distillation of Esthonian "kukkersite" ) has been termed
"esto-bitumen" or "esto-asphalt," which unlike paraffin petroleum
asphalts is completely miscible with coal tar in all proportions. 8

CHAPTER XVII
COAL TAR AND COAL-TAR PITCH

Under the headings "Coal tar" and "Coal-tar pitch/' will be
included t^e tars and corresponding pitches recovered as by-products
from bituminous coal * in :

i) Gas works;

2} Coke ovens;

3) Blast furnaces;

4; Gas producers;

5) Low-temperature processes.

Water-gas tar and water-gas-tar pitch have been included by
some writers within the scope of the terms coal tar and coal-tar pitch
respectively, but in this treatise they will be considered separately,
since they differ in their composition and properties, due to the use
of petroleum products in their manufacture.

Bituminous Coals Used. Bituminous coals only are suitable for
the production of coal tar. Cannel, bog-head and anthracite coals
will not answer, since the former distils at too low a temperature,
and the latter contains insufficient volatile matter. Upon subject-
ing cannel coal to low-temperature distillation, there is obtained 20
to 40 per cent of cannel-coal tar having a specific gravity at 50 C.
of 0.9, containing much paraffin and 5 to 10 per cent phenols. At
20 C. cannel-coal tar has the consistency of butter. Upon subject-
ing bog-head coal to low-temperature distillation, 30 to 60 per cent
of tar is produced, having a thick, salve-like consistency and con-
taining solid paraffins, phenols and naphthenes, but no naphthalene
or anthracene. It is known as bog-head-coal tar. Torbanite on
distillation yields 20 to 35 per cent of torbanite tar having a spe-
cific gravity at 35 - C. of 0.90 to 0.95, and containing phenols and
a small amount of solid paraffin.

Bituminous coals are known as "gas coals'* when used for manu-
facturing illuminating gas, and "coking coals" when used for coking.
Western Pennsylvania, West Virginia, Virginia, eastern Kentucky

836

XVII TEMPERATURE OF TREATMENT 337

and Tennessee produce most of the bituminous coals used for these
purposes, and they comply with the following characteristics:

Air-dry loss of coarse material i -5 per cent

Moisture at 105 C. (powdered material) i . 5-7.0 per cent

Volatile matter on ignition 20 -40 per cent

Fixed carbon 50 -75 per cent

Ash Less than 1 5 per cent

Sulfur . . , . Less than a per cent

Hydrogen 4. 5-5. 5 per cent

Carbon 65-85 per cent

Nitrogen i~2 per cent

' Oxygen 5-1 5 per cent

Very little is known regarding the chemical composition of the
bituminous coal itself, due to the difficulty in converting the coal
into recognizable derivatives, and because of its slight solubility in
the usual solvents for bituminous materials. On subjecting coal to
high temperatures, the bodies present decompose into simpler sub-
stances which fail to give any clue as to their original structure and
composition. Recent researches lead to the conclusion that coal is
essentially a conglomerate of cellulose decomposition products, ad-
mixed with altered resins and gums originally present in the plants
from which the coal was derived.

Temperature of Treatment. D. T. Jones examined the tars
derived from the destructive distillation of bituminous coal in vacuo
at very low temperatures (below 450 C.). These were then sub-
jected at atmospheric pressure to successively increased tempera-
tures up to 800 C. Unsaturated hydrocarbons, naphthenes, paraf-
fins, phenols, aromatic hydrocarbons and pyridines were found to
be present in the low-temperature tar, whereas benzol and its homo-
logues, naphthalene, anthracene, phenanthrene and the solid aro*
matic bodies were absent. As the temperature was increased, the
naphthenes, paraffins, and unsaturated hydrocarbons were trans-
formed into olefines. As the temperature was further increased,
the olefines were in turn transformed into benzene and its homo-
logues. The percentage of olefines appears to reach a maximum
at 550 C., and a minimum at 750 C., at fahich latter temperature
hydrogen and naphthalene are rapidly evolved^ as well as methane.
The conclusion reached is that ordinary coal tar obtained from
bituminous coal at high temperatures results chiefly from tlie de-
composition of the tar previously formed at lower temperatures.

338

COAL TAR AND COAL-TAR PITCH

XVII

The following figures will give a rough idea of the effect of the
temperature on the yield and characteristics of the tar produced
from an average grade of British coal :

Tempera-
ture

Tar

(Gals:
per Ton)

Sp. Gr.
Tar at
77 F,

Free
Carbon
in Tar,
Per Cent

Distillate to 315 C.

Pitch
(Per
Cent by
Weight)

Naph-
thalene,
Per Cent

Paraffin,
Per Cent

Coke-ovens (narrow)

1300 C.
1100-1350 C.
900-1200 C.
1000-1100 C.
1000-1200 C.
400-700 C.

8.0
9-5

11.
12.
15-5
18.3

1.210
I. 200
I.I90

1. 155
1. 100
1. 035

20
IS

5.5
I

30-35

20-30
15-20
5-12

o
o
Trace

5
13
25

72
' 66
65
58
48
40

Horizontal retort

Inclined retort

Vertical retort ,.,..,..*

Low-temperature carbonization

By low-temperature carbonization of coal is meant its destruc-
tive distillation under ^700 to 800 C. Below this temperature
range there are evolved mostly condensable tars and oils, with a
minimum of fixed gases; whereas above this range, mostly fixed
gases are produced, due to secondary reactions. This is illustrated
.by the following figures applicable to i ton of average coal con-
taining 25 to 30 per cent volatile matter:

Low-temperature
(Coalite Process)

High-temperature Processes

Gas Works

Coke Ovens

Temperature of vapors. .....
Yield gas

550 C
6,000-6,500 cu. ft.
rich gas (700-750
B.t.u.)
lo gal. tar (*)
15 Ib.
14 cwt.

1,000 C.
12,000 cu.ft. medium
gas (550 B.t.u.)

10 gal. tar
25 Ib.
13$ cwt.

1,200 C.

11,500 cu. ft. lean
gas (450 B.t.u.)

8 gal. tar
28 Ib.
14-14$ cwt.

Yield liquid products. .......

Ammonium sulfate

Yield coke

* Absence of naphthalene and anthracene distinguish this tar from high-temperature tars.

The percentage yield of tar, figured on the weight of coal
treated) will approximate the following:

Gas works (horizontal retort) 5-7 per cent

Gas works (vertical retort) 4-6 per cent

Cokevovens 2-6 per cent

Low-temperature carbonization 8-13 per cent

ation *.,..* 5" IQ P cr cent

XVII

PRODUCTION OF GAS- WORKS COAL TAR

339

The commercial processes for obtaining coal tar will now be
considered.

Production of Gas-works Coal Tar. In manufacturing illumi-
nating gas, bituminous coal is heated in comparatively small fire-

t/5

2
c

clay retorts, of D-shaped, oval or round cross-section about 16 to
24 in. in diameter. The D-shaped retort is ordinarily used in

840 COAL TAR AND COAL-TAR PITCH XVII

modern gas-works because it is least liable to distortion under the
>action of heat, and moreover presents the greatest area at its base,
enabling the contents to be heated more rapidly. In some cases the
retorts are ''single-ended," measuring 8 to 9 ft. in length, but mod-
ern practice favors the use of "double-ended" retorts composed of
three Sections joined together, measuring 15 to 25 ft over all. In
the single-ended retort a metal mouthpiece is bolted to one end, to
which in turn the gas outlet pipe is fastened. With the double-
ended retort, metal mouth-pieces are bolted fast to both ends, From
6 to 9 retorts are set together in a common brick setting, consti-
tuting a "bench" which is heated by a single furnace.

Retorts Used. The retorts are supported in either a horizon-
tal, inclinfed of vertical position. The inclined or vertical retorts
seem to meet with greater favor since they avoid overheating, pre-
vent the formation of "free carbon" in the tar, and at the same
time permit the coke to be handled by gravity. The vapors leave
horizontal retorts at 1600 to 1800 F. and the vertical and inclined
retorts at 1300 to 1400 F.

The retorts are heated with water-gas obtained by passing air
and steam through incandescent coke beneath the "bench." The
coke used for this purpose is derived as a residue from a previous
charge of bituminous coal, amounting to 15 to 25 per cent of the
total coke produced. The water-gas is burnt in flues surrounding the
retorts and the process of combustion controlled by the introduction
of air. This method of firing results in a higher and more uniform
terfiperature with the minimum consumption of fuel. The tempera-
ture in the combustion chamber ranges from 2800 to 3200 F., and
in the flues surrounding the retorts from 1900 to 2200 F. An im-
proved installation of horizontal retorts is shown in Fig. 103, in-
clined retorts in Fig. 104, and vertical retorts in Fig. 105. Con-
tinuously operating. vertical retorts are now being adopted exten-
sively, in which the coal is fed through the retort in a constant
stream, the coke being withdrawn continuously at the bottom.

Formerly, the retorts were charged and discharged by hand,
using a shovel and rake respectively. Mechanical devices are now
used for the purpose, the double-ended horizontal retorts being
charged ;* both^tids with a scoop, fed from an overhead hopper,
operated ei thereby, compressed air or electricity. About 600 Ib, of

XVII

PRODUCTION OF GAS-WORKS COAL TAR

341

coal are introduced into the double-ended retort, and subjected to
heat from 3 to 6 hours. The inclined and vertical retorts are
charged through the top and discharged by gravity from the lower
end. Horizontal retorts are discharged by a pneumatic or an elec-
trically driven ram, which
forces out the coke at the far-
ther end. Inclined retorts are
set at an angle between 25 and
35, which is sufficient to en-
able the coal to feed into the
low r er end, where it is held in
place by a metal cover. In
the inclined and vertical types
the volatile constituents are
withdrawn from the upper
end.

The vapors are subjected
to the highest temperatures in
the horizontal retort, due to
the longer contact with the
heated internal surfaces,
which results in a larger per-
centage of free carbon, and a
tar of higher specific gravity.

Methods of Recovering
Gas-works Coal Tar. The
volatile products pass from
the retort into the hydraulic
main, which forms a water-
seal, permitting any retort to
be charged, and at the same
time preventing the gas gen-
erated in the other retorts es-
caping through the open one.
The hydraulic main reduces the temperature of the vapors to 130-
160 F.

After leaving the hydraulic main the vapors are subjected to
the following treatment in modern gas-works :

From "Coal and Coke," by F. H. Wagner
FIG. 104. Inclined Gas- Works Retort.

342

COAL TAR AND COAL- TAR PITCH

XVII

(1) The gases are passed through a "primary condenser"
which may either be air-cooled or water-cooled, or both.

(2) The gases are then passed through a tar-extractor.

(3) Then they are passed through an exhauster to relieve the
pressure on the retorts and force the gases through the ensuing
train of apparatus.

(4) The gases are next passed through two "scrubbers," pref-
erably of the rotary type. In the first scrubber the gases are washed
with a heavy tar oil, such as anthracene oil, to remove the naphtha-

FlG, 105. Vertical Gas- Works Retort.

lene, and in the second with an alkaline solution of ferrous sulfate
to remove the cyanogen.

(5 ) The gases are then cooled to about 60 F. by passing them
through a "secondary condenser," similar to the first one.

(6) The ammonia is next removed by passing the gases through
a third scrubber through which a stream of water is allowed to
trickle. Formerly a tower scrubber filled with a checker-work of
wooden boards was used for this purpose, but this is being replaced
by a rotary scrubber similar to tnat used for extracting the naph-
thalene and cyanogen.

XVII PRODUCTION OF GASWORKS COAL TAR 343

(7) The last step consists in passing the gases through a series
of "purifiers," consisting of low cylindrical chambers llled with
trays or sieves. Some of the purifiers are filled with slaked lime to
remove carbon dioxide and a portion of the sulfur compounds, and
others with iron oxide to remove the remainder of the sulfur com-
pounds (mostly hydrogen sulfide).

Products Obtained. The following percentages of tar are col-
lected from the hydraulic main, condenser, washer and scrubber,
also the tar extractor respectively:

Hydraulic main 61 per cent

Condensers 12 per cent

Washer and scrubbers i per cent

Tar extractor 12 per cent

Total 100 per cent

The operations which take place in the final handling of illuminat-
ing gas before it enters the mains, cease to be of interest in relation
to the production of tar, and will accordingly be omitted.

In the United States, temperatures to which the retorts are
heated vary from 900 to 1500 C. In England the average tem-
perature is 1 1 00 C. In Germany horizontal retorts are heated
between 1000 and 1 100 C., and inclined retorts between 1 100 and
1200 C. The quantity and yield of the tar depend largely upon
the temperature. In the low-temperature production of illuminating
gas, an average of 16 gal. of tar is produced per ton of coal, and in
high temperature processes an average of 8. The maximum varia-
tion ranges between 4 and 20 gal. of tar per ton. High-tempera-
ture processes are preferable, as they increase the yield of gas, but
have the disadvantage of reducing its illuminating power.

The following represent the yields from an average grade of
bituminous coal in manufacturing illuminating gas:

Gas 17 per cent (10,000 cu. ft.)

Aqueous liquor 8 per cent

Tar 5 F r cent

Coke 70 per cent

Total loo per cent

Of course, these figures are subject to variation, and depend
upon the quality of bituminous coal used, the temperature at which
it is distilled, etc. Thus the yield of gas per ton of rich coal will
vary from 5000 to 15,000 cu. t M and the residual coke from 55 to
75 per cent.

344 COAL TAR AND COAL-TAR PITCH XVII

The tar collected from the hydraulic main, condenser, washers
and scrubbers is run into wells constructed of metal or masonry,
sometimes heated with steam-coils and allowed to settle as long as
possible, to permit the aqueous liquor, which is lighter than the tar,
to rise to the surface, where it is drawn off and treated separately
to recover the ammonium compounds. The well-settled gas-works
tar carries between 4 and 10 per cent of water. In exceptional
cases the water may run a$ high as 40 per cent, although this is not
regarded with favor.

Production of Coke-Oven Coal Tar. 2 As stated previously,
about 78 per cent of the coal tar produced annually in the United
States is obtained from coke-ovens equipped to recover by-products.
This only represents between 60 and 70 per cent of the total quan-
tity of bituminous coal converted into coke. The remaining 30 to
40 per cent is coked in brick "beehive" ovens, constructed in the
form of a beehive, and not adapted to recover the gas, ammonia or
tar, which are allowed to burn away through an opening iri the top
of the oven, thus constituting a reckless waste of our national re-
sources, running into many millions of dollars annually. For years
this wasteful practice remained unchecked, but happily the present
tendency is to replace the beehive ovens with types adapted to
recover by-products, and it is probably only a matter of a few years
more before all the coke-ovens will be equipped to recover the gas,
ammonia and tar. This same wasteful tendency is reflected in a
patent granted in the United States and describing the production
qf coal-tar pitch by the simple expedient of igniting coal tar and per-
mitting the more volatile constituents to burn off (sic!). 8

In European countries, on the other hand, where the tendency
has always been towards a greater economy, coke-ovens have long
been perfected to recover these by-products. In this connection it
must be borne in mind, whereas it is absolutely necessary to remove
the tar in manufacturing coal gas for illuminating purposes, this
does not prove to be the case where the coal is converted into coke
for metallurgical industries. This, and the comparative cheapness
of bituminous coal in the United States, also the low price com-
manded by the by-products until recently, will account for the laxity
4% conserving them.

The temperature of coking varies between 1000 and 1100 C,

XVII PRODUCTION OF COKE-OVEN COAL TAR 345

and rarely above the latter inside the retort. The external tempera-
ture of the retort may run as high as 1700 C. The adaptability of
coal for coking purposes is indicated with a fair degree of certainty
by the ratio of hydrogen to oxygen, together with the. percentage
of fixed carbon calculated on the moisture-free basis. Practically
all coals with an H : O ratio of 59 per cent or over, and less than 79
per cent of fixed carbon, possess that quality of fusion and swelling
necessary to good coking. Bituminous coals with a ratio down to
55 will produce a more or less satisfactory coke, whereas coals with
a ratio as low as 50 are unsuitable for coking purposes.

Retorts Used. The present systems of by-product oven con-
struction resolve themselves into two types depending upon whether
the flue construction is horizontal or vertical. In either type the
coking takes place in a narrow, retort-shaped chamber about 33 ft
long, from 17 to 22 in. wide, and about 6 l / 2 ft. high. The width
of the chamber averages 19 ft, which has proven suitable for com-
pleting the coking within twenty-four hours. The retort holds be-
tween 12 and 14 tons of coal.

The ends of the retort are closed by means of iron doors lined
with fire brick, which after being closed as tightly as possible are
luted with clay to prevent the entrance of air. The coal is charged
into the top of the oven, then pushed into place and leveled by me-
chanical devices. At the end of the coking, the doors are opened
and the coke removed by a ram, the red-hot coke being immediately
quenched with water.

The number of ovens in a battery varies between 40 and 100,
depending upon the type of construction. The oven walls are con-
structed of fire brick containing about 95 per cent of silica, which
on account of its very high fusing-point enables the ovens to be
worked at high temperatures, and at the same time proves to be an
excellent conductor of heat.

For a detailed description of the various types of coke-ovens
in use, the reader is referred elsewhere.

The coking in the by-product oven is in reality a destructive
distillation process, the heat required being supplied by burning a
portion of the gases evolved. A large excess of gas is produced
amounting to between 40 and 60 per cent of the total

Products Obtained. The following yields per ton are recovered :

346 COAL TAR AND COAL-TAR PITCH XVII

Gas. ....... t 15.0-16.0 per cent (8,500-10,500 cu. ft.)

Ammonium sulfate 0.8- 1.3 per cent

Tar 3.0- 6.4 per cent

Coke 70.0-75.0 per ent

Approximately 20 per cent of the nitrogen present in the coal is
converted into ammonium compounds, part of which is found in
the tar as pyridine, quinoline, etc. About half of the nitrogen re-
mains in the coke, and may be regarded as lost.

The vapors emanating from the coke-ovens are passed through
various forms of condensers and scrubbers to separate the am-
moniacal liquor and tar, which are sirhilar to those used in gas
works. The yield of tar recovered from coke-ovens varies from 4
to 15 gal. per ton, depending upon the kind of coal used, as well as
the type of coke-oven. Over 90 per cent of the tar (anhydrous)
condenses in the collector main and primary coolers, 2 per cent in
the exhausters, and 7 per cent in the tax-extractor.

The following constituents have been identified in coke-oven
coal tar produced in the United States : 4

Light oil: Per Cent

Crude benzene and toluol 0.3

Coumarone, mdene, etc ' 0.6

Xylenes, cumenes and isomers . i . i

Middle and heavy oils:

Naphthalene . 10.9

Unidentified oils in range of naphthalene and methylnaphthalenes i . 7

a-Monomethylnaphthalene I . o

j8-Monomethylnaphthalene 1.5

Dimethylnaphthalenes ^ 3.4

Acenaphthene 1.4

Unidentified oils in range of acenaphthene i .o

Fiuorene 1.6

Unidentified oils in range of fluorene 1,2,

Anthracene oil:

Phenanthrene 4.0

Anthracene i . i

Carbazol and kindred nonbasic nitrogen-containing bodies 2.3

Unidentified oils in range of anthracene 5.4

Phenol 0.7

Phenol homologues (largely cresols and xylenols) 1.5

Tar bases (mostly pyridine, picolines, lutidines, quinolines and acri-

dine) 2,3

Yellow solids of pitch oils 0.6

Pitch greases * 6.4

Resinous bodies 5,3

Pitch (460 F. fusing-point) f 44. 7

Total 100. o

XVII PRODUCTION OF BLAST-FURNACE COAL TAR 347

Production of Blast-furnace Coal Tar. 6 Most blast-furnaces in
the United States employ coke as fuel and a few use anthracite
coal. Since all the volatile constituents have been removed from
coke, and as anthracite coal contains only a very small percentage,
no tar is obtained when either of these is used for smelting ores in
blast-furnaces. In such cases the gases evolved are subjected to a
purification process merely to remove the entrained dust, before
using them for heating purposes.

Owing to the scarcity of anthracite and the high cost of bitumi-
nous coal in Europe and Great Britain, there is a tendency to reduce
the operating expenses by using the latter in its raw state, without
first converting it into coke. A non-coking bituminous coal must be
selected for this purpose. In such cases the gases emanating from
the blast-furnace carry a certain amount of tar, derived from the
volatile constituents of the coal, which must be removed before they
can be used for heating or power purposes. The gases also carry a
comparatively large amount of dust derived from the ores in the
blast furnace, of which a good portion is removed by passing the
hot gases through a device known as a u dry dust-catcher/ 1

Methods of Recovery. After being dry-cleaned, the gases are
subjected to a wet-cleaning and cooling process by passing them
through coolers, scrubbers, or washers. The centrifugal washer is
usually preferred as it operates rapidly and economically. A part
o/ the tar condenses in the coolers, and the balance in the scrub-
bers and washers. , It carries a large quantity of the wash water,
which may be separated.

Approximately 7 gal. of blast-furnace tar and 29 Ib. of ammo-
nium sulfate are obtained from each ton of bituminous coal fed into
the blast-furnace. It appears that the iron ore and other minerals
introduced with the coal, influence the yield of tar. Thus the same
bituminous coal gave the following weights of tar per ton under
varying conditions:

Distilled alone in gas works 114 Ib. of tar

Distilled with English iron ore 66 Ib. of tar

Distilled with sand 170 Ib. of tar

The tar derived from blast-furnaces always carries a substantial
proportion of mineral matter, which the dust-catchers fail to re-

348 COAL fAR AND COAL-TAR flTCH XVII

move, and which serves to distinguish it from the other varieties of
coal tar.

Blast-furnace coal tar on distillation yields a greenish-brown
creosote of low viscosity, with 30-35 per cent phenolic content, also
a pitch of rather paraffinoid character. A typical tar tests as fol-
lows: specific gravity at 60/60 F., 1.151; water by volume, 0*2
per cent; phenols in tar, 14.6 per cent; bases in tar, 2.5 per cent;
pitch at 315 C., 56.6 per cent of medium hardness and paraffinoid
character; and distillate to 315 C., 43,4 per cent, having a specific
gravity at 60/60 F. of 0.980; naphthalene little to none; and min-
eral matter 13.0 per cent

Production of Producer-gas Coal Tar. 6 Unless the producer-
gas plants are of a large capacity (above 4000 horse-power) it does
riot pay to recover the by-products. The smaller producers are
designed to decompose the tar vapors and convert them into per-
manent gases, to avoid the expense of operating a tar-separating
plant on one hand, or the trouble occasioned by the tar clogging the
pipes and valves on the other. In plants where the producer gas is
used without separating the tar, it is necessary to shut down about
one day a week to clean out the gas lines. In spite of this, it is
only in tin-plate plants, where particularly clean gas is required, that
the practice is followed of scrubbing the producer gas to remove the
tar. Of the larger installations, the Mond by-product gas producer
is virtually the only one which is designed to recover the tar and
ammonium sulfate. Upon operating this type of producer at low
temperatures, as high as 150 Ib. of water-free tar is recovered per
ton of coal, consisting of paraffins, olefines and naphthalenes, with
smaller quantities of aromatic hydrocarbons and phenols.

Production of Low-temperature Tars. 7 Low-temperature car-
bonization processes are carried on at 400 to 700 C., or an average
of 600 C, in layers about 4 in. thick. The industry dates from
1906, when Thomas Parker (who originated the term "coalite")
patented a plant for carbonizing coal at low temperatures. The
yields are roughly as follows per ton of coal carbonized:

(1) Gas, 3000 to 3500 cu. ft. from externally heated retorts,
or 20,000 to 25,000 cu, ft from internally heated retorts.

(2) Tar, 20 to 25 gal

XVII

PRODUCTION OF LOW -TEMPERATURE COAL TARS

349

(3) Ammonium sulfate, 10 to 25 Ib.

(4) Coke, 15 cwt.

Low-temperature tars are of a liquid consistency and contain a
comparatively small quantity of free carbon. They consist of 50
to 80 per cent of hydrocarbons and 20 to 50 per cent of tar acids.
The hydrocarbons are mainly paraffins and saturated cyclic hydro-
carbons, with varying amounts of naphthenes and unsaturated hy-
drocarbons. Benzol, toluol, and other aromatic hydrocarbons are
entirely absent, or present only in traces. The tar acids consist
mostly of the higher phenols of viscous to resinous character, with
very little true phenol, and comparatively little cresol or xylenol.
They also contain but small quantities of nitrogen and sulfur de-
rivatives.

The type of coal used exerts a greater influence upon the char-
acter of the tar than does the particular mode of treatment, and in
general, much variation occurs in the composition and character of
the tars produced commercially. The creosote oils derived from
low-temperature tars are too low in specific gravity to meet the
current specifications in the United States. Less pitch is obtained
than with high-temperature tars, and its character is quite different,
and generally poorer in quality.

The following yields are obtained from an average British me-
dium-coking coal, subjected to various carbonizing temperatures,
expressed in percentage by weight of the moisture-free coal :

400C.

45o e C.

joo'C.

55oC.

6ooC.

65oC.

7ooC.

Tar (per cent)

l.o

5.62

7.06

8.00

7.60

6.00

6.24

Tar (gal* per ton)

9. i

12.8

16.0

17.6?

l6.4

14.15

12. O

Tar (specific gravity at 60 F.)
Aqueous distillate (per cent) * .

0.958

5.6

0,980

7.OI

0.986

7.02

1.015

7.70

1.039

8.12

1.078
8. 20

1. 080
7.18

Gas (per cent)

2.2

3. 12

4. O<

7. 14

Q.IO

IO.54

14. $8

Coke (per cent) .

88 2

8l.7<

80. <o

77.OO

75.00

71.00

7I.OO

Loss (per cent)

O.I

O.1O

O.47

0.16

0.18

0.16

I.OO

Pitch (per cent in tar) ,..,.,.,

22.2

28.8

27.

11.4

14.6

41.0

52. I

Pitch (fusing-point degrees C.)

41.2

17.

52.2

64.5

go.5

01. C

95.8

Pitch (specific gravity at 60 F.) .......

1. 11

1. 12

1. 14

1. 17

1.21

1,25

1. 20

Pitch (free carbon per cent) .

14.. 2

<, 1

4.6

11.

28.1

26.8

25.1

In Germany, low-temperature tar is termed "Urteer," and in
Great Britain it is known under various names, such as "coalite

350 COAL TAR AND COAL-TAR PITCH XVII

tar," "carbocoal tar," "Mond tar," "Delmonte tar," etc., depend-
ing upon the particular type of apparatus in which it is produced.

The reader is referred to other sources for a complete descrip-
tion of the numerous types of retorts which have been devised for
the low-temperature process of carbonizing coal.

Properties of Coal Tars. As stated previously, the expression
"coal tar" is properly applied to tars derived directly from coal
without admixture of petroleum. Coal tars differ in their physical
properties, depending upon their method of production. The fol-
lowing types are distinguished:

( i ) Gas-works coal tar

(a) Horizontal retorts

(b) Inclined retorts

(5) Low-temperature coal tar.

The figures in Table XXIII will give a general idea of the
physical properties of the main types of coal tar in their dehydrated
state :

The following colorimetric test may be used to detect low-tem-
perature tars: on shaking 1-2 ml. of the oily distillate with 5 ml.
aqueous ferric oxalate or ferric citrate, the aqueous layer will as-
sume a dark blue coloration, which will turn a lemon-yellow upon
acidifying with N/io sulfuric acid and then regain its blue tint on
neutralization, but turns purple and then bright red upon adding an
excess of alkali. High-temperature tar oils will not give this
reaction. 3

Methods of Dehydrating Coal Tar. It is customary to dehy-
drate coal tars at their point of production, to avoid paying freight
charges on the water content. Provision is usually made for the
gravity -separation in storage tanks of as much water as possible,
but the amount that may be removed in this manner varies in the
case of different tars, their mode of production, and other factors.
With high-temperature coal tars the settled product is In the nature
of an emulsion, with the water as the disperse phase. The amount
of water held in stable suspension is greater in the ca& of horizontal

XVII

PROPERTIES OF COAL TAR

351

I 2 .

H M 1
i5 O i

dd'

8 *,

45^8

O
M *o O

8 ^

>D a

O O O O OOHe*

55 ^

rr
feig feiifefc

I fr'f*
5 lifts

HjUMnljtyi^

I
3

till

.4MilIillii MlPl!

G&ff&K&gS3&&*ff&& ' s

ft tn to "tt '

S fi ^eee&

II iiijilsiii Hi

bfc bbbfcbbfcfcbb bbb

352

COAL TAR AND COAL-TAR PITCH

XVII

gas-retort tar than in coke-oven and vertical gas-retort tar, and still
less with water-gas tar, ranging from 3 to 10 per cent in the case of
the first named, down to i to 2 per cent in the last Sometimes, the
emulsion is of a different nature, in which the tar forms the disperse
phase and the water content ranges from 15 to 70 per cent. Such
emulsions are most difficult to break up by the usual means of set-
tling, even at high temperatures. They may, however, be treated
by a partial distillation, as will be described later.

Dehydration may simply imply the removal of the bulk of the
water from a tar, so as to render it suitable for distillation, or as is
the case in Great Britain, it may include the removal of the light
oils as well, resulting in the production of a refined tar suitable for
road purposes or other uses.

The following methods have been used for dehydrating tars:

(i) Settling. When the tar is allowed to settle in storage
tanks, the water rises to the surface, where it is drawn off through a
series of outlet pipes in the side. This process may be facilitated,'

? articularly in the case of viscous tars, by heating to about 200 F.
y means of steam coils in the bottom of the tank, supplied with
exhaust steam from other plant operations. Many variations of
simple settling have been suggested, but at best they remove but a
portion of the water, and are generally supplanted by one of the
methods which follow*

(2)' Use of Centrifuges. This method has been used with
more or less success abroad, and only in the case of tars with tars of
low free-carbon content, so as to avoid the necessity of frequent
cleaning. The tar is first heated to a temperature of 40 to 50 C.

and run into the rapidly revolving
drum of a centrifugal separator,
illustrated in Fig. 106. The tar
being heavier than the water is
forced to the periphery, the water
forming a cylindrical layer inside.
An annular diaphragm A attached
to the upper part of the centrifugal
has a ring or perforations where it
comes in contact with the drum at
B. The crude tar is introduced
through thepipe C below the dia-

FIG. 106. Centrifugal Tar Dehydrator* phragm. The speed with which

the drum revolves causes the tar
to flow through the perforations into the upper portion of the cen-

XVII METHODS OF DEHYDRATING COAL TAR 353

trifugal, where it is removed through the pipe D. The water is
drawn off through E below the diaphragm, which bars its passage
into the upper section. This method is particularly suited for treat-
ing tars having approximately the same specific gravity as water, as
for example water-gas tar. The centrifugal is revolved at a speed
between 2000 and 3000 r.p.m. Tars containing between 30 and
90 per cent of water will have the percentage reduced to less than
i per cent in one treatment. A large portion of the free carbon
contained in the tars is also removed, and affixes itself to the inner
walls of the drum from which it must be scraped occasionally.

( 3 ) Horizontal Stills. These are used to a considerable extent
in Great Britain according to the continuous dehydrating methods
proposed by Hird, Chambers and Hammond. 9 They depend upon
the use of a horizontal still heated by tubes at the bottom, through
which the furnace gases are passed. The tar to be dehydrated is
caused to flow through the still to a depth of about 6 in. over the
tops of the heating tubes, and a heat-exchanger is used on the incont*
ing wet tar and the outgoing^ hot dry tar, so as to preheat the for-
mer. Two or several stills in series may be employed, depending
upon the amount of water carried by the tar and the tonnage to be
treated per day.

(4) Tube Heaters. This process has been devised by T. O.
Wilton, 10 and has met with favor in Great Britain. The tar is
treated continuously upon being heated to 170 to 190 C. under a
pressure of 30 to 50 Ib. per sq. in., by pumping through a coil of
pipes in a furnace heated with coke. It is then released into a vapor
chamber at atmospheric pressure, whereupon the water and light
oils evaporate, since they are maintained at a temperature consider-
ably higher than their boiling points. This is accompanied by
copious frothing, due to the fact that each volume of water is
converted into 1640 volumes of steam. As this method involves the
charging of hot tar to the tube heater, no heat exchanger is used.

(5) Cascade System. In Great Britain, this system has been
patented by William Blakeley, 11 who allows the heated tar to flow
over a series of trays arranged in a casing, the trays being intercon-
nected by pipes which also serve to support them. The tar is intro-
duced in the top tray and is allowed to flow from tray to tray, while
the steam or other heating medium is introduced in the pipes at the
bottom tray, and is conducted from tray to tray upwards. A devel-
opment of this process has been used successfully in the United
States in a cascade dehydrator, consisting of a rectangular steel
chamber enclosing a series of steel pans fitted with steam coils. 12
The pans are set at an incline w r ith alternate pans sloping in oppo-
site directions, so as to form a cascade. Pumps are provided for
handling the crude and dehydrated tar, also the distillate. The tar

354 COAL TAR AND COAL-TAR PITCH XVII

is introduced through a manifold at the top of the casing wKich
delivers it to a distributing box over the top pan, whence it over-
flows from pan to pan and leaves the bottom of the casing free from
water* The vapors are conducted to a combination vapor-condenser
and tar-preheater whence they are condensed by the raw tar on its
way to the distributing box. A second water-cooled condenser is
provided as a safeguard. The distillate is withdrawn from the
second condenser by a vacuum pump, which serves to maintain a
vacuum of 3 to 4 in. of mercury on the casing. The dehydrator is
operated so that the exit tar attains a temperature of 275 to
285 F., which assures its complete dehydration. A sufficient pres-
sure is applied to the tar before entering the casing to prevent the
evolution/ of vapors, this particular feature being similar to the
Wilton system. A dehydrating unit of this type handles 37,000 gal.
of gas-works coal tar in twenty-four hours, reducing the water con-
tent from 7.7 per cent to o.i per cent; likewise 60,000 gal. of tar
containing 4 per cent water, and 100,000 gal. containing 1.8 per
cent water; in both of the latter instances reducing the water con-
tent to o.i per cent

Methods of Distilling Coal Tar. 18 Coal tar is transported from
the gas-works or coke-ovens in cylindrical steel tank-cars 7 to 8 ft.
in diameter and 28 to 30 ft. long holding about 10,000 gal., pro-
vided with a dome on top and heating coils inside for the introduc-
tion of steam in cold weather to reduce the fluidity. It is transported
by water in tank-vessels constructed similarly to those used for pe-
troleum, holding up to 300,000 gal. At the distilling plant, the tar
is generally stored in covered vertical cylindrical steel tanks larger
in diameter than height, having a capacity up to 2 million gallons.
A certain amount of water separates during storage which is tapped
.through pet-cocks in the side. Less often the tar is stored in rectan-
gular reinforced concrete tanks built underground.

Tar when heated to a temperature, usually in the neighborhood
of 700 F., will crack and decompose, giving off permanent gas with
the formation of insoluble matter, known as "free carbon." This
reaction increases in velocity as the temperature increases, and
varies of course with different tars. The effect of this reaction is a
smaller yield of distillate to a given consistency of pitch residue, or
in other words, it means that the pitch is produced at the expense
o the yield of oils. Since the oil is the more valuable product, the
cracking is regarded as undesirable. The amount of cracking is a

XVII METHODS OF DISTILLING 'COAL TAR 355

function of both temperature and time, increasing directly with
either of these factors. The ideal system of tar distillation may be
regarded as one which exposes the tar to the lowest temperature for
the shortest possible time necessary to obtain the desired product.
The practical effect of these factors may be exemplified by some
results on a coke-oven tar run to a pitch of 300 fusing-point A
reduction in the time of heating from twelve to one and one-half
hours resulted in an increase of 16 per cent in the yield of oils and
a corresponding decrease in the amount of pitch. Similarly, where
the time was kept constant, a lowering of the final still temperature
by 200 F. accomplished approximately the same result. Greater
yields of oil may be obtained by decreasing both the time and tem-
perature, although the effects are not necessarily additive.

One method consists in increasing the still heating surface, so as
to increase the heat input in a given time, and this leads to the
continuous tube-still of one type or another, where the time factor
is reduced materially over the batch stills. Another method is to
reduce the still temperature by lowering the vapor pressure of the
oils through the use of steam, vacuum, or inert gases, as will be
described presently.

The following methods have been used for distilling coal tars :

( i ) Simple Batch Stills. The first stills used in the tar industry
in Europe^were constructed in the form of a "pot" or verticaf still
having a concave bottom, as illustrated in Fig. 107, where i repre-
sents the manhole; 2, safety-valve connection; 3, swan neck; 4, swan
neck stool; 5, dipping tap; 6, steam inlet; 7, steam pipe; 8, tar inlet;
n, tar outlet. The concave bottom is claimed to have the advan*
tages of providing a larger heating surface, also to assist in draining
off the pitch and to accommodate the expansion and contraction of
the metal plates without setting up dangerous strains. Steam is
introduced during the process of distillation through a perforated
pipe (910) at the bottom and serves to carry off the vapors more
rapidly, also reduce the time of distillation. English stills hold 20
to 40 tons (4000 to 6000 gal.) of tar, and are mounted on suitable
brick settings adapted for direct heating with coal or producer gas.

The vapors leave the still through a large pipe connected with
the condenser coils immersed in water in a rectangular tank. These
coils are constructed of pipes ranging from 6 in. down to 3 in^in
diameter. The distillate is run into small measuring tanks which
in turn empty into large storage tanks. Each fraction is caught

356

COAL, TAR AND COAL-TAR PITCH

XVII

separately, four fractions all told being recovered, viz.: light oil or
crude naphtha, middle or carbolic oil, heavy or creosote oil and
anthracene oil.

In the United States the customary form of batch still consists
of a horizontal cylinder with convex ends, heated directly with oil,
coal or gas, constructed to hold in the neighborhood of 50 tons

(10,000 gal.) tar. Such stills
are about 9 ft in diameter by 20
ft. long, and about half the
diameter, or 500 sq. ft, is avail-
able as heating surface. They
take ten to twenty hours to com-
plete distilling a charge to a
pitch, where 40 to 45 per cent of
oil is removed from the tar. A
typical still is illustrated in Fig.
1 08. The tar enters through a
pipe into the top of the still, and
the vapors are drawn off through
another pipe of large diameter
attached directly to the top of
the still, at the center. The stills
are not usually provided with
domes, as is the case with petrol-
eum stills. The outlet pipe for
the pitch is located at the bot-

From "Coal Tar Distillation,"
by A, R. Warnes.

FlC.

107. Vertical Still
Coal Tar.

for Refining

torn, together with inlet pipes for
steam or air agitation. The stills
are mounted on a brick setting provided with a fire arch to in-
sure uniform heating, and prolong the life of the bottom. The
process is an intermittent one. After the tar has been distilled to
the desired fusing-point or consistency, the residue of pitch is dis-
charged by gravity, pumping or blowing out with air,

In recent years the batch stills have been somewhat improved by
the use of internal flues to increase the heating area and serve to
reduce the time of distillation, also to minimize the carbon deposi-
tion. A modern installation is illustrated in Figs. 109 to 113, con-
sisting of two primary stills of 9000 gal. each and three secondary
stills of 8000 gal each. The primary stills are of the vertical type
and serve as preheaters, since they are equipped with spiral steel
flues through which the gases from the secondary stills are passed,
as illustrated in Fig. in. From the primary 'stills the heated tar is
run into the secondary stills, where direct heat is applied, and the
bulk of the distillation takes place; these are shown in Fig* 112.

XVII

METHODS OF DISTILLING COAL TAR

357

The pitch is run from the secondary stills to the pitch copiers of
about 5000-gaL capacity each, which are illustrated in Fig. 113*
The vapors are condensed in a vertical shell-and-coil type of con-
denser filled with water, which is located directly below the primary
stills, from which the distillate is run into the storage tanks.

Another arrangement consists in operating the batch still in
connection with a dehydrator of the continuous type, which has the

of The 'Barrett Company.
FlG. 108. Horizontal Still for Refining Coal Tar.

advantage of conserving heat and also obviates the danger of foam-
ing during the distillation process.

(2) Vacuum Distillation. Vacuum of 26 to 28 in. mercury
may be used to advantage in connection with batch stills when run-
ning to a hard pitch of 280-300 F. fusing-point Much better
yields of oil are obtained (e.g., about 10 per cent at a 300 F.
fusing-point pitch) than by distillation under atmospheric pressure,
and the reduction in cracking also has the effect of lowering the per-
centage of free carbon in the pitch. In general, the use of vacuum
does not materially influence the products until a pitch of 140 F.
fusing-point is reached, but from there on the vacuum has Decided
advantages as compared with ordinary operations, although when

358

COAL TAR AND COAL-TAR PITCH

XVII

the fusing-point of the pitch reaches a fusing-point of 300 F. or
thereabouts, a certain amount of cracking begins, accompanied by
the evolution of gas, which makes it impractical to maintain the

HO-J30. t l

;|| t

J!^ Ammonia 5,000 Gaf. U J > ~Vg^

<? \4^~~T) -J $<

^ ^Pumped to Ammonia &

5tomqeby*IOPump

wi Oil Heavy Ot /s ^ C///5

25,OOQ6a/ t 25flOQQaL 25 t OOOGai 2$0006al,

O" O 1 O"" 0"'

IW2W 230-270* 270-300' 300'+

Pumped from Pumped f/vm Pympedf/vm Pumped from

AccJankfhru Rec Jan k thru RecJanksihru Rcclanksthru

*IQPump *lOPump *IIPump *HPump

Tar

SYMBOLS

------ Oil-230-270

-------- 0,1-270'- 300*

------- OiL300'+

FIG. 109, Flow Diagram of Dry Tar to Light and Heavy Oils.

FIG. no. Cross-section of Tar Distillation Plant

necessary degree of vacuum. In distilling to a pitch of 220 F.
fusing-point, the final still temperature is 750 F. at atmospheric
pressure, in comparison to 570 F. when distilled under a vacuum

XVII

METHODS OF DISTILLING COAL TAR

359

of 28 in. mercury. In a vacuum distillation plant, the oil receivers
must be in parallel, connected with suitable piping, so that one may
be released to empty it, without disturbing the vacuum on the rest
of the system.

K- - ~ 3-(f J

FIG. in. Primary Tar Still.

An alternate procedure consists in agitating the tar with steam,
using a vacuum of about 15 in. of mercury. The following figures
were obtained on coke-oven tars of 9 per cent free carbon :

360

COAL TAR AND COAL-TAR PITCH

XVII

Final Still
Temp. C.

Per Cent by Weight

Pitch Tests

Pitch

Oil

Air M. Pt.

Free Carbon

Atmospheric

400
300

64-3
55-9

34-9
43' I

220 F,

216 F.

35 -3 per cent
26.1 per cent

Vacuum of 28-in. . . ,

FIG. 112. Direct-fire Secondary Tar Still.

' In general, the softer the pitch produced, the less will be the
advantage of vacuum distillation.

Heating in a bath of molten metal under vacuum has also been
suggested. 14

(3) Steam Distillation. The passage of superheated steam
through the contents of the batch still also serves to reduce the dis-

FIG. 113. Pitch Cooler.

tillation temperature and to minimize the cracking, 15 but the amount
of steam required is so great, that its use has not proven practicable
from the standpoint of cost and on account of the greatly increased
condenser surface required. This, however, does not apply to the
use of a small amount of steam to agitate the contents of the still,
where th$ distillation takes place at atmospheric pressure.

The effect of large volumes of steam is indicated by the follow-

XVII

METHODS OF DISTILLING COAL TAR

361

ing figures/ 8 where steam was passed at a rate of o.i i cu. ft. (cor-
rected at 77 F. to 760 mmj per gallon of tar per minute, ap-
plicable to a coke-oven tar of 8.5 per cent free carbon content:

Final Still

Per Cent by Weight

Pitch Tests

Temp. C.

Pitch

Oil

Air M. Pt.

Free Carbon

Ordinary distillation.

413

57.8

40.1

280 F.

40. 7 per cent

Steam distillation. . .

340

47.0

50.6

*79 F.

28,8 percent

It may be noted that the steam consumption was such that the
condensed water approximately equaled the volume of the "oil"
recovered on distillation.

(4) Gas Re circulation. By circulating an inert gas such as
nitrogen or carbon dioxide through the contents of the regular batch
stills at the rate of i to 20 cu. ft. per 100 gal. tar, per minute, the
vapor pressure of the oil vapors is lowered, coupled with a reduc-
tion of the still temperatures and an increase in the yield of distil-
late. 17 This procedure merely involves the addition of a gas recir-
culation pump and closed distillate receivers to the batch-still equip-
ment. In practice, no provision is made for the inert gas, as the
system may be filled with air at the start, since in a short time the
oxygen is used up and the recirculation gas becomes nitrogen. The
formation of free carbon is minimized, and the distillation may be
carried to a much further point without danger of coking of the
still contents. Whereas pitches of about 300 F. fusing-point rep-
resent the hardest that may be produced commercially by the fore-
going distillation methods, with the recirculation method, pitches of
400 to 450 F. fusing-point may readily be obtained, and with a
correspondingly greater yield of distillate. Thus, with a coke-oven
tar of 8.5 per -cent free carbon content, 65 per cent by weight of
distillate was obtained upon running to a pitch of 400 F. with a
carbon deposit in the still no greater than was the case upon run-
ning to a 250 F. fusing-point pitch by the ordinary method, with
only 40 per cent distillate.

A comparison of the oil yield by the gas-recirculation method
on the same type of coke-pven tars referred to under the captions
"Vacuum Distillation" and u Steam Distillation," is given below*
The gases were recirculated at a rate of 0.33 cu. ft \ corrected to
77 F. and 760 mm.) per gallon of tar per minute, in the case of
CO 2 , and at the rate of 0.40 cu. ft. (corrected to 77 F* and 760
mm.) per gallon of tar per minute, in the case of N 2 : r

.16

362

COAL TAR AND COAL-TAR PITCH

XVU

Final Still
Temp. C

Per Cent by Weight

Pitch Tests *

Pitch

Oil

Air M. Pt.

Free Carbon

Atmospheric.

4i3
358
33i

57.8
46.9
46.4

40.1
52.6
52.0

280 F.
277 F.
*77 F.

40 . 7 per cent
29.0 per cent
27 . 2 per cent

Recirculated COz
Recirculated N2

(c) Continuous Stills. Various expedients have been pro-
posed 18 to transform the batch distillation process into a continuous
operation, as for example placing several stills in series and flowing
the tar through them consecutively and taking different fractions
from each still^ allowing the pitch to flow from the last in the series.
In Great Britain two continuous systems of tar distillation are in
use, as devised by H. P. Hird and E. V. Chambers Respectively.
The Hird process 19 involves the use of four stills, three of which
are connected in series, the first two being heated by internal flues
and the third being arranged for the introduction of steam. The
fourth still is used for the production of pitch. Separate condensers
for each still and suitable heat exchangers are provided. The first
still is maintained at 190 C, the second at 240 C., the third at
325 C, (producing creosote oil), and the fourth at 275 C. The
stills are provided with a series of vertical baffles and the tar flows
through the system in a comparatively thin layer. The Hird system
is only adapted to producing pitches ranging in fusing-point up to
200 R

The Chambers process is a modification of the cascade system
used for dehydrating tars. It involves the use of two stills provided
with cascades, three condensers and one heat interchanger. The
crude tar is preheated by flowing through the heat interchanger,
and then caused to flow down the cascade in still No. i, followed
by a return through the bottom of the still which is kept about one-
third full of tar. The tar then passes through the 'still No. 2 in a
similar manner, and finally into Still No. 3 which is not equipped
with a cascade, where the residue is distilled to pitch with the intro-
duction of steam. Still No. i is maintained at 210 C. and pro-
duces light oil, still No. 2 is kept at 260 C. and produces light oil
and creosote, still'No. 3 is kept at 320 C. and produces anthracene
oil and a residue of pitch. It is claimed that a plant of this type
will successfyilly handle a Mond or water-gas tar containing as
much as 30 per cent of water.

(6) Tube Stills. These operate on the principle of heating the
tar by passing it through a coil of pipe surrounded by the heating
medium, and then allowing the vaporization of the oils to take

XVII METHODS OF DISTILLING COAL TAR 363

place in a vapor chamber at the exit of the coil, thus handling the
tar continuously.

In Great Britain the Wilton process 20 has met with much favor,
and consists of a modification of the method described previously
for dehydrating tar. The Wilton tube-still for the continuous dis-
tillation process consists of two successive heating coils in series,
.followed by a cylindrical still in which superheated steam is intro-
duced, with expansion chambers in between each unit. The first
coil heats the tar to 200 C. under a pressure of 30 to 50 Ib. per
sq. in. and removes the light oils and water. The second coil heats
the tar to 230300 C. and removes the creosote oil. The last
still removes the anthracene oil by means of the superheated steam
at 360 C M and separates the pitch.

Other types used in Europe include the so-called "Sadenwas-
ser" 21 and "Leinweber" 22 stills, named after the makers.

Similar stills are in use in the United States with very satisfac-
tory results. 23 They utilize a single heating coil when running to
pitches of about 200 F. fusing-point, and two heating coils when
running to a 300 F. pitch, which is about as hard as can be pro-
duced in this type of apparatus. The crude tar is first introduced
as cooling means in the various oil condensers, whereby it is heated
sufficiently, so that when released into an expansion chamber, the
water and light oils are vaporized and condensed, whereupon the
dehydrated tar is pumped through the first heating coil. After
passing through the first coil, the tar is sprayed into a second ex-
pansion chamber where the creosote oil is taken off to fractional
condensing means, and the residual intermediate pitch pumped
through a second coil in the same furnace as the first coil, but in a
hotter zone, and the same process repeated. For the softer grades
of pitch the second stage may be omitted. The use of vacuum in
the second stage will serve to still further reduce the operating
temperatures. 24 The smallest still of this type handles from 30,000
to 50,000 gal of tar per day, depending upon the character of the
tar and the grade of pitch desired, whereas the largest unit in op-
eration in the United States has a capacity of 90,000 to 140,000
gal. tar per day. The yield of oils in such stills will run 10 to 15
per cent better than the ordinary batch still in producing pitch of
300 F. softening-point, due entirely to a reduction in the time of
heating to less than one-fifteenth that required in the latter. The
general flow relationship of a well-developed tube-still installation in
the United States is shown in Fig. 114. *

^ Continuous fractional condensing columns have been developed
which separate the vapors into sharper fractions than were previ-
ously obtainable^ in the batch stills. Furthermore, a number of
closely cut fractions may be obtained simultaneously and continu-

364

COAL TAR AND COAL-TAR PITCH

XVII

ously from the mixed tar vapors, in a properly designed and con-
structed condensing column, including* the separation of creosote oil,
naphthalene oil, heavy oil and anthracene oil.

(7) Collector-main Condensers. A process has been devel-
oped 25 in the United States, in which tars of the desired consistency
may be separated directly in the collector-main of the coke-oven, by
scrubbing the hot vapors with the preheated tar, or else with some,
of the recovered oils, yyhich are introduced in the form of a spray.
These serve to remove the tarry matter from the vapors, which are

H..C.~ HEAT EXCHANGE COMtH$tR3.

FIG. 114. Flow Diagram of Continuous Tube-still for Coal Tar.

thereby cooled and at the same time the gases are enriched. The
equipment is illustrated diagrammatically in Fig. 115.

The process operates as follows : the hot gases from the ovens
pass up the ascension pipes, i, into the collector main, 2, which is
connected at one end with the 'foul gas or air-cooled main 3. The
two mains have a continuous fall in the direction of gas flow, and
tar is circulated through them by the pump, 4, and gravitates back
to the tank, 5, accompanied by the heavier tar fractions which have
condensed from the gas.

The essentially valuable feature of the process is that road tar
of any required standard can be withdrawn from the air-cooled or
foul gas mam at point 6, at which the temperature of the gas is
stiirabove the dew point of the lighter tar constituents, which are
carried forward with the gas. By a simple manipulation of this
fundamental ohvsical condition or the foul eas stream, road tar

XVII RECOVERY, TREATMENT OF COAL-TAR DISTILLATES

365

may be produced, continuously or intermittently, the tar so ob-
tained being superior in essential respects to that produced by de*
hydration or distillation in stills. Perfectly dry road tar may be
run while hot from the seal pot, 12, to the receiver, 11, where the
viscosity is checked and adjusted, if necessary, by mixing with oil
or road tar of suitable consistency.

With a pitch run to 300 F. fusing-point, a 70 per cent oil yield
is claimed, as compared with 44 per cent in a batch still. Creosote
oil as well as hard pitch may be collected in a similar manner. Hard
pitch may be burnt as fuel, or returned to the coke-ovens with the
charge of coal.

This process represents quite a forward step, and is rapidly
being adopted in by-product coke-ovens, both in the United States

FIG. 115. Collector-main Condenser for Coal-tar Distillation,

and abroad, since it is both more efficient and economical than the
use of condensers and scrubbers.

Recovery and Treatment of Coal-tar Distillates. On refining
coal tar by any of the distillation processes previously outlined, one
or more of the following distillates are obtained:

(1 ) Light Oil. At the commencement of the distillation proc-
ess, the light oil or u crude naphtha" distils over, and comprises the
entire distillate lighter than water, being obtained below a vapor
temperature of 200 C, This fraction is first washed with alkali
to remove the tar acids, and then redistilled and fractioned into
crude benzol, toluol, solvent naphtha (xylol) and heavy naphtha.

(2) Middle Oil This is generally considered to include the
fraction boiling between 200 and 250* C In some cases it is mi^ed

366 COAL TAR AND COAL-TAR PITCH XVII

with the ensuing fraction the heavy oil provided the mixture will
meet existing specifications for creosote oil. In other cases the
middle oil is first extracted with caustic soda to remove the tar acids
before it is mixed with the heavy oil, for use as creosote. Still
another alternative consists in redistilling the middle, oil in fire-
heated stills to separate it into the following fractions : crude naph-
tha up to 210 C, acid-naphthalene oil from 210 to 250 C, and
creosote oil above 250 C. The crude naphtha is treated with
caustic soda to remove the tar acids and then worked up with the
light oil fractions. The acid-naphthalene oil is first cooled in pans
to crystallize out the naphthalene, whereupon it may either be mar-
keted as such under the designation "tar-acid oil," according to the
percentage of tar acid content (e.g., 15 per cent, 25 per cent, 50
per cent, etc., as the case may be), or it may have the tar acids
removed and marketed as naphthalene oil.

In Germany, the practice consists in distilling the middle oil in
a fire-heated vacuum column still, which gives much closer boiling
fractions, as follows: crude heavy naphtha up to 200 C., a second
fraction from 200 to 220 C. containing the bulk of the cresylic
acid and comparatively little naphthalene, next a closely cut naph-
thalene oil fraction carrying a high percentage of crude naphtha-
lene, leaving a residue of so-called creosote oil.

The tar acids extracted from the various fractions ^ obtained
principally from the middle oils are obtained as their sodium salts,
which in turn are treated with carbon dioxide to liberate the tar
acids, phenols, etc. These acid products are separated and mar-
keted under the following designations: phenol, cresols, 97-^99 per
cent straw-colored cresylic acid, 95 per cent dark cresylic acid,
ortho-cresol, meta-cresol, para-cresol, etc. They are variously used
for the production of emulsifiable disinfectants, cattle sprays, and
as flotation oils for the concentration of certain grades of mineral
oils.

(3) Heavy Oil. This is variously known under the terms
heavy oil, creosote oil and dead oil, and may either represent the
fraction between 250 C. to the end of the distillation, or the frac-
tion between 250 C. and the anthracene oil fraction. United
States practice consists primarily in adjusting the heavy oil fraction
to meet the various specifications established for creosote oil for
use in wood preservation. 26 This may be accomplished by con-
trolling the distillation range of the fraction, or by mixing together
various fractions obtained from the middle and heavy oil respec-
tively. In either case, it is advisable to remove any naphthalene by
cooling and filtering.

(4) Anthracene Oil Unless it is intended to extract anthra-
certfe, the anthracene oil fraction is not made, and the entire cut is

XVII RECOVERY AND TREATMENT OF COAL-TAR RESIDUALS 367

worked up for creosote oil. Where it is intended to produce an-
thracene, the anthracene oil fraction is cooled in pans or tanks until
the anthracene crystallizes out, whereupon it is filter-pressed to
obtain a cake containing 2030 per cent anthracene, or else sub-
jected to a hot hydraulic pressing to remove more oil and produce
a cake containing 30-40 per cent anthracene. The anthracene is
used principally to produce alizarin and other coal-tar dyes.

Recovery and Treatment of Coal-tar Residuals. At the close
of the distillation process the residual product consists either of
coal-tar pitch, or else refined coal tar, depending upon its physical
characteristics. There is no sharp line of demarcation between the
two, although, in general, residuals having a fusing-point above
80 F. (cube method Test 15^) are known as pitches, whereas
those fusing below are considered refined coal tar. The charac-
teristics of a given residual will vary with the nature of the tar,
the particular method of distillation, and the quantity of distillate
removed. When the distillation has been completed, the hot pitch
is run into coolers illustrated in Fig. 113, and when the temperature
falls to 250 to 300 F. the product is either run into barrels or into
a large rectangular concrete enclosure known as a "pitch bay,"
where it is allowed to solidify. Various methods have been sug-
gested to facilitate the handling of hard pitches, 27 consisting in
molding it, 28 rapidly cooling the pitch and breaking it into frag-
ments, 29 comminuting the product, 30 dropping the melted pitch from
an elevation into a body of water, 81 forming an aqueous suspension
with a peptizing agent, 82 etc.

If the distillation is continued to the desired point, then the
residue is known as "straight-run coal-tar pitch." On the other
hand, if the distillation is carried to a point where the residue is
harder and more infusible than desired, and is thereupon fluxed to
the desired consistency and fusing-point, either with certain frac-
tions of the distillate 3S or a flux of different origin usually of little
value commercially or with other tars, 84 then the pitch is known
as "cut-back coal-tar pitch." S5

It has been claimed that coal-tar pitch treated with petroleum
distillate (e.g., naphtha) and steam in a heated vessel with agita-
tion, and then being allowed to settle, will separate into (a) a
clear supernatant liquid suitable for use as a paint vehicle, and (b)

368 COAL TAR AND COAL-TAR PITCH XVII

a pitch-like mass suitable for the manufacture of roofing com-
pounds. 86 Processes have been described in which low-temperature
coal tar is distilled to a pitch in the presence of NaOH ; * r likewise
the steam-distillation of coal-tar pitch with Fe 2 3 and FeCl 3 in com-
bination with montan wax, whereupon distillates are said to be ob-
tained composed of waxy and resinous products. 88

The crystallization* of naphthalene, anthracene, phenanthrene,
etc., from coal tars and their distillates may be inhibited by adding
a small percentage of stearyl chloride. 89

Coal-tar residuals have found many uses in the arts, among
which may be cited the following: very soft pitches and refined
coal tars are used for saturating felts ; for dust-laying purposes on
roads and pavements; as the base of various kinds of paints and
protective coatings for metals, masonry, and other structural ma-
terials. Moderately soft pitches having a fusing-point between 80
and 120 F. are used principally for road binders and sometimes
for waterproofing work. Medium hard pitches having a fusing-
point between 120 and 160 F. are used for constructing "pitch-
and-felt roofs"; for laminated membranes used in waterproofing
foundations of buildings, tunnels, subways and bridges; as pipe-
dips ; as a binder in constructing bituminous concrete and macadam
pavements; for filling the joints in block pavements; and for manu-
facturing the better grades of bituminous paints. Hard pitches
having a fusing-point between 160 and 212 F. are used principally
as a binder for fuel briquettes. Very hard pitches having a fusing-
point above 212 F. are employed as a binder for sand-cores in
forming castings of iron and steel; for manufacturing electric-light
carbons, battery carbons, carbon brushes for motors and dynamos,
black "day pigeons" for target shooting, and sundry plastic com-
positions for insulating purposes, as a filler for rubber goods, 40 etc*
It has been pointed out 41 that very hard coal-tar pitches (fusing-
point between 300 and 400 F.) may be cut-back upon melting with
pitches of a lower fusing-point.

Coal-tar pitches are remarkably resistant to the disintegrative
action of water, and are therefore well adapted for sub-soil water-
proofing. They are more weather resistant than wood-tar pitch,
rosin pitch, lignite-tar pitch; shale-tar pitch and bone-tar pitch, but

XVII RXCOrERY AND TREATMENT OF COAL-TAR RESIDUALS 369

are Inferior to carefully prepared residual asphalts obtained from
jaetroleum, blown petroleum asphalts, wurtzilite asphalt, fatty-acid
pitches and pure native asphalts containing approximately the same
percentage of volatile matter.

J The manufacture of pitch-coke has assumed considerable irnpor-
ance in recent years, for use in the metallurgical industries, espe-
cially in the production of certain high-grade castings, on account of
,fts extreme purity and freedom of deleterious mineral constituents
Whkh are present in coke produced directly from coal, also^ for
manufacturing electrodes. Pitch-coke results when coal-tar pitch
fc distilled in a retort until ail the volatile ingredients have been
Driven off. As the distillation proceeds beyond the anthracene oil,
the character of the distillate assumes a grease-like consistency,
\vhich thickens as the distillation proceeds. At the same- time a
strong evolution of gas (mainly hydrogen) takes place, accom-
panied with a certain amount of ammoniacal liquor. The residue
at this stage is very pasty and of a high fusing-point and there is
Considerable danger of the still foaming over. As the heating is
continued, the mass cokes and the distillate appears as a transpar-
ent ruby-red resinous substance, having a specific gravity above 1.22,
known as "pitch resin," which melts between 40 and 100 C. 4 * The
temperature at the close of the distillation ranges between 800 and
1000 F. . The yield of resin may be increased by distilling the
pitch with steam in the presence of Fe 2 O 8 and FeCX 48 Another
type of pitch resin (fusing-point 105-110 C) may be obtained
fft>m the sludge produced in refining the light oils with sulfuric
a$id, which is neutralized with caustic soda and distilled to 225-
300 C, under a vacuum of 28 in. 44 The character of the pitch-
coke varies, depending upon the type of apparatus in which the
pitch is coked, the time of heating, and the final temperature at-
t^ined. It consists of practically pure carbon, except for 0.2 to
0.5 per cent ash. In Europe the distillation is performed in
special cast-iron pot stills with large doors or man-holes to facili-
t$te cleaning, holding i to 2J4 tons of pitch, which are run on a
thirty-six hour cycle. The resulting coke is quenched with water
and then chopped out of the still by hand. The pitch charged
ifsually has a fusing-point of 60 to 75 C., and the products ob-

37$ COAL TAR AND COA&TAR WZTJEf ^ .

, . * * ' ' ' ' $ *

tamed include 30 to 40 per cent of aa 0range<plored waxy grft*s?
(specific gravity 1.14 to 1.22); 4 to 6 per cent of pitch-resin^
traces of aimmonia; and 56 to 60 percent of pitch-coke. :' '*

In the United States a large quantity of pitch-coke has^b^eh
produced by first preparing d pitch having a fusing-point of 400 t
450 F. by the recirculation method of distillation, 45 which is therj
coked in a bee-hive type'of coking oven, 46 no attempt*being rrfadfe
to. recover the by-products which are employed to furnish the hea^
required for the coking operation. The pitch used has a fusing?
point (cube method Test i$c) of 440 F. and fixed carbon (Teit
19) 63 per cent. A charge of 6.5 tons may be coked in sixty-foil^
hours at a maximum temperattire of 1100 F. The coke is the^
quenched with water and removed, whereupon it contains i pe
cent of volatile constituents, 0.48 per cent ash and 0.38 per cent
sulfur, being, approximately 98 per cent pure carbon. The usual
unit is a 5000 gal. still with a 4000 to 4500 gal. charge, operating
on a 48 hour cycle, yielding 60 to 75 per cent oil from coke-oven
tars, A modified type of pot-still is also used, consisting of a cyliri*
drical still set horizontally in brickwork, so that its entire circum*
ference is surrounded by the hot gases, thereby preventing con-
densation and speeding the distillation process. 47 Alternate pro-
cedures consist in distilling in vacuo; mixing the pitch with coke
breeze and charging same into'the coke ovens; 45 spraying the melted
pitch with steam into the coke-oven chamber ; 40 etc. A cellular pitch
coke suitable for use as a decolorizing agent may be obtained by
distilling coal-tar pitch with NaOH, KOH, MgO, or CaO. 50 *

The successful coking of pitch has provided the necessary oi#-
let for the surplus production, which cannot be disposed of through
the regular channels.

Table XXIV gives a schematic outline of the various products
derived from coal upon distilling it destructively, including the
commercial substances produced from coal tar, as practiced in the
United States.

Properties of Coal-tar Pitches. The figures in Table XXV will
serve to give a general* idea of the limiting physical characteristics
oi the pnhcipal types of coal-tar pitdht ' in

: Chttrch and Wfeiss examined representative Specimens of coal-
tar pitches,** with the following results, in which A represents gas-

TABLE XXIV

PRODUCTS DERIVED FROM COAL,

COAL

. I , .

| .A. |

GAS LIQUOR * 1 COKE |

1 1 I I I 1 1 1

II III II 1 1

1 D?. A o" 1 1 BEN20L 1 1 TOLUOL 1 1 XYLOLS 1 1 SULF UR ||CVANOGE^|"- 1 - UM 3 ,NAT.N!JJ ryEL M |

|T;;T,A S I 1 s& \ \*T\ K^\\^^^nfo^i\ \'SKS&M \ f ETAL co u K\ CICAt l 1 ** \ \ TO TIC 1 tem^l

II |

i .

1 | _

iii

[xANIHATCEjI^^^IJJ [sULPOCYANIDEJ (FenROCYANIDtj | 1

1 1 |LUBRICANT| [CRUCIBLE) [iLECTHooEs|

j ;'.._.._ -L -. T/>

r"x||*j]o N J f CYANIDE | |FERRICYANIDE| f~ l '''S!e* N ~l

1 , 1

I ... I

|,M^1| . ||P*,HT| |. OOF,NG||T MM K W ,H.|

[ HARD

PITCH [

XVIl

PROPERTIES OF COAL-TAR PITCHES

371

ill

i iJ

!U*

j! 3S,

B j ' H'~ I 't!'^'~ l S $J StS^-^S 4> fc*^^

1 Hli

'^^KSS^Iig f-a-s 'aff^ifta^ll Si?
UBIXIIIIIIiSlI III IIIII'I2|J ||8

eeeeebbebbbb

372

COAL TAR AND COAL-TAR PITCH

XVII

works coal-tar pitch obtained from horizontal retorts, B gas-works
coal-tar pitch from inclined retorts, C gas-works coal-tar pitch from
vertical retorts, D Otto-Hoffman coke-oven coal-tar pitch, E Semet-
Solvay coke-oven coal-tar pitch, and F Scotch blast-furnace coal-
tar pitch.

TABLE XXVI

(Test 7) Sp.gr. a t6o/6oF...
(Test 9*) Hardness at u 5 F . . , .
Hardness at 77 F

1.30

Too soft

1.28

Too soft

1.19

Too soft
44

1.25

Too soft
4*

1.25

Too soft
39

1.23

3*4
4 1

Hardness at 32 F
(Test i$c) Fusing-point (cube
method) F

I2<

2
123

2
125

3
126

2
126

8
135

(Test 19) Fixed carbon (per cent)
(Test 21) Sol. in carbon disul-
fide (per cent)

41-5
64,9

37-0
67.8

I6. 3
89.5

28.5
79*9

28.2
82.5

14.4
58.2

Non-mineral matter
insoluble (per cent).
Mineral matter (per
cent)

34-9

0.2

32.0

0.2

10,3
0.2

19.7
0.4

17.4
O.I

30.0
11. 8

(Test 22) Carbenes (per cent)
(Test 31) Free carbon (per cent)

3-5

34-9

2.8
30.8

" 5-3
8.0

7-4
21. 1

5-9
18.3

2.6

28.4

"A sample representing a well-advertised brand of straight-run
gas-works coal-tar pitch marketed for built-up roofs was tested by
the author with the following results :

(Test 7) Specific gravity at 77 F i.*S

(Test 9*) Hardness at 1 1 5 F 95

Hardness at 77 F ao

Hardness at 32 F o

(Test 9*) Consistency at 115 F 5-

Consistency at 77 F

.Consistency at 32 F

(Test 9<f) Susceptibility index

(Test 10*) Ductility at 115 F

Ductility at 77 F

(Test 9^) Ductility at 32 F

(Test 1 1) Tensile strength at 1 1 5 F

Tensile strength at 77 F 4-05

Tensile strength at 3* F 8.5

(Test 15*) Fusing-point (cube method) "* F,

(Test 16) Volatile matter, 500 F. in 5 hrs 8.2 per cent

(Test 17*) Flash-point * 3$o F,

The consistency, tensile strength (multiplied by id) and duc-
tility curves of this specimen are shown in Fig* 116. *

24.7
> 150

> IOO

35
75-5
o

0.15

XVII

PROPERTIES OF COA^TAR PITCHES

373

Coal-tar pitches are characterized as follows: 52

1 ) Jet-black streak on porcelain,

2) Carbonaceous matter clearly visible under microscope.
3 ) Comparatively high specific gravity.

4) High susceptibility index. This means that they are
largely influenced by changes in temperature, becoming brittle in
winter, and softening under extreme summer heat.

77'

115

140
ISO
120
110
100
90
60
70
60
50
40
30
20
10

ll /"

LEGEND
Hardness

_. , jffgjyfafajQ)

. Ductility

O Fusing fVnt

\
\

r
i

{ .

*^V

15.5

46.5

\ AOL

( 3

^. \

ft,

hJHB

^l.

F* 1 !

rjri-rr

=233

BBtaM

its

t i

10 20 30 40 SO 60 70 80 90 100 110

Temperature, Degrees Fahrenheit

FlG. 1 1 6. Chart ot Physical Characteristics of Coal-tar Pitch*

(5) High ductility when tested at temperatures ranging be-
tween the solid and fluid states.

'6) Characteristic odor on heating.

^7) Pass rapidly from the solid to the fluid state.

[8) Comparatively high percentage of volatile constituents

i heated at ?oo r . for five hours.

when

(9) Comparatively high percentage of fixed carbon. ,

(10) Comparatively high percentage of non-mineral matter in-
soluble in carbon disulfide ("free carbon").

N ( 1 1 ) Comparative insolubility in petroleum naphtha,
(12) Comparatively small percentage of sulfur.

374 COAL TAR AND COAL-TAR PITCH XVII

( 13 ) Naphthalene present in most instances.

(14) Solid paraffins are either absent or present in small
amounts.

15) The sulfonated constituents are soluble in water.

(16) The distillate to coke contains a comparatively large
tmount of tar acids.

(17) Give the diazo reaction.

( 1 8 ) Very slightly soluble in ethyl alcohol, forming a yellowish-
brown solution, with an intense greenish-blue fluorescence.

Low-temperature coal-tar pitches may be differentiated from
high-temperature pitches, since the former:

contain more phenolic bodies.

contain solid paraffins.

contain traces to no naphthalene and anthracene.

Attempts have been made to oxidize coal-tar pitches in the fol-
lowing ways : heating in air with MnO 2 or HNO 3 ; 53 heating in air
with MnO 2 and NH 4 C1; 54 blowing at an elevated temperature (e. g.
370 C.) by the same process used for treating petroleum as-
phalts ; 55 blowing with air under pressure ; 56 blowing with air in the
presence of sulfur; 57 blowing with air in the presence of sulfur,
CaO and KC1O 8 ; 58 blowing with air in the presence of MeCHO
and NH a ; 59 blowing with air in the presence of H 2 SO 4 ; 60 blowing
with air in the presence of H 2 SO 4 and a persulf ate or perborate ; 61
blowing with air in the presence of Fe 2 O 3 ; 62 blowing with air in
the presence of FeCl s or Fe 2 O 3 containing sulfur; 68 treating with
oxygen at an elevated temperature in the presence of boric, phos-
phoric or hydro-iodic acid; 64 blowing with oxygen in the presence
of nitrous oxides; 65 first emulsifying a mixture of coal-tar pitch and
heavy tar oils with an aqueous solution of Na 2 CO 3 and Na 2 SiO 3 and
then adding BaO 2 . 66 Processes have also been described for blowing
a mixture of coal-tar pitch with saponified vegetable oil, 67 or with
asphalt or lignite-tar pitch. 68

The presence of comparatively large amounts of volatile con-
stituents results in disproportionately high losses in the blowing
operation. Samples tested by the author showed a slight lowering
of specific gravity, a decrease in the hardness for a given fusing-
point, a decrease in the susceptibility factor (L e*, the material was
less affected by changes in temperature) and no appreciable change

XVII PROPERTIES OF COAL-TAR PITCHES 375

in the ductility. Blown coal-tar pitches have not been marketed,
nevertheless they warrant further development.

Coal-tar pitches may be vulcanized by heating with sulfur; 69
or a mixture of sulfur and alum; 70 or a mixture of sulfur and
CaOCl 2 ; 71 or with an alkaline polysulfide or antimony sulfide ; 72 or
with spent Fe 2 O 3 (obtained in the purification of coal gas) in the
presence of FeCl 3 or MnSO 4 ; 73 or with S 2 C1 2 (with or without sul-
fur) 7 * or by heating with H 2 SO 4 ; 75 or by heating with H 2 SO 4 and
subsequently heating to a higher temperature until the acid is de-
composed; 76 or with organic nitro- or sulfochloride derivatives; 77
or with SaCla or thionylchloride and then combined with phenol-
formaldehyde resin; 78 or by treating a mixture of coal-tar pitch
and vegetable oil with nitric acid and vulcanizing with sulfur; 79
or by heating a mixture of coal tar and vegetable oils or fats with
H 2 SO 4 . 80 These processes serve to raise the fusing point of the
pitch and make the product more resistant to temperature changes.
In Germany, sulfurized coal-tar pitch has been marketed under the
name "Holzzement" for cementing together layers of coal-tar satu-
rated felt in constructing built-up roofs. 81

A type of coal-tar pitch suitable for use in constructing steep
built-up roofs and which will not run or flow at high sun tempera-
tures when exposed at angles in excess of 30 may be prepared as
follows: distilled coal-tar pitch or coke-oven-tar pitch is heated
to 550 F. and 2 to 3 per cent of ammonium sulfate or zinc sulfate
is incorporated, the heating being continued until dissolved. During
this treatment the pitch is hardened and its fusing-point (Test i$c:
cube-in-air method) raised to about 400 F. It is thereupon cut
back with 30 to 40 per cent anthracene oil. The final product,
known as "rubber pitch" has a low susceptibility, and tests as fol-
lows:

(Test 7) Specific gravity at 77 F i . 240

(Test 9^) Penetration at 115 F 55 to 65

Penetration at 77 F 20 to 22

Penetration at 32 F 5 to 9 *

(Test ij<r) Fusing-point (cube method) 180 to 190 F.

(Test 31) Free carbon 33 to 36 per cent

Coal tars and coal-tar pitches may be deodorized by treating
with formaldehyde or paraformaldehyde in the presence of acids or
alkalies followed by blowing steam through the heated mass. 82 Coal

376 COAL TAR AND COAL-TAR PITCH XVII

tars may be hardened and toughened, and thereby rendered less sus-
ceptible to temperature changes, by converting the phenols, cresols,
etc., in situ, into formaldehyde condensation products (i.e., phenolic
resins) as follows: coal tar (1000 parts) is mixed with formal-
dehyde (10 parts) and ammonia of sp, gr. 0.880 (5 parts), then
digested 8 hours at 70 C. in a closed vessel, whereupon a catalyst
(e.g., CuSO 4 or FeSCX) is added and the mass blown with air for
I o to 30 hours, during which process the temperature is gradually
increased to 193 C. The resultant product has been marketed
under the name "Bitural". 88 Similarly, synthetic resins may be pro-
duced from the fraction of low-temperature coal tar, distilling be-
tween 170 and 230 C. (containing phenols), by heating to 100 C.
with aqueous 40 per cent formaldehyde and a basic catalyst, such as
caustic soda, pyridine, trimethylamine, or tri-ethylamine, until three
layers are formed. The upper layer consists of neutral oils and
unaltered phenols, the middle layer is aqueous, whereas the lower
layer consists of phenolic resins. 84

Coal-tar pitch may be treated with chlorine in the presence of
a chlorine carrier, which serves to increase its lustre, hardness and
fusing-poirit, resulting in a product which resembles asphalt. 85 An
asphalt-like product may also be obtained by mixing coal-tar pitch
either with the insoluble constituents precipitated from coal tar by
treatment with benzol, or with cumarone resin which has been
heated to 270 C .*'

A process of cracking at 510-750 C. in a tube-still serves to
convert coal tars into a product which sulfonates completely upon
digesting with H 2 SO 4 . 87

The percentage of free carbon in coal tars and coal-tar pitches
may be increased by heating under pressure between 700 and
820 R* 8

The following pitches are produced in small amounts, princi-
pally in Germany, as by-products in the refining of coal-tar deriva-
tive^:

Anthracene Pitch. (Anthracene-oll-tar Pitch}. This is ob-
tained as^a residue upon the purification of anthracene by distilla-
tion^ and is characterized by being hard, black and glossy. Anthra-
cene pitch may be hardened by heating with sulfur, or with spent
irbn oxide obtained in the purification of coal gas. 90 Anthracene

XVII NAPHTHOL AND CRESOL PITCHES 377

pitch may be used for various purposes, including briquette
binders. 91

Naphthol Pitch. This is obtained in the refining of betanaph-
thol or naphthylamine. 92 It is a glossy black solid, fusing at about
120 C, and is almost completely soluble in solvent naphtha (xylol)
chloroform and pyridine. Upon boiling with aqueous caustic soda
it yields naphthol, which may be identified qualitatively. Its f using-
point may be increased by heating with formaldehyde in the pres-
ence of a mineral acid, 93 and a rubber-like product is obtained upon
fluxing with a vegetable oil and adding fillers. 94 Naphthol pitch
may be used in the manufacture of lacquers and for molding com-
positions. 95 Naphthylamine pitch is obtained as a by-product in the
refining of naphthylamine.

Cresol Pitch. This is obtained as a residue in the distillation of
crude cresol, and is known in Germany under the names "Karbol-
pech," "Kresolharz" and "Phenolpech." It has a fusing-point of
60 to 80 C., a decided cresol odor on heating and a brownish-black
color. It is more or less soluble in aqueous caustic potash and al-
most completely soluble in alcohol and mixtures of alcohol and
benzol. 98 It is similarly used in the manufacture of lacquers.

CHAPTER XVIII
WATER-GAS AND OIL-GAS TARS AND PITCHES

Water-gas tar, oil-gas tar and their corresponding pitches are
not classified with "coal tar" and "coal-tar pitch/' as they are inter-
mediate in their properties between the latter and petroleum
asphalts, on account of the petroleum products used in their manu-
facture. They are accordingly included in a separate chapter.

Carburetted Water-gas Tar. The mechanism of this process
has already been briefly described. A modern water-gas plant hav-

Generator Carbureter , Superheater

Scrubber Condenser

FIG. 117, Lowe Water-gas Plant.

ing a capacity of 1 1 / 2 to 3 million cubic feet of gas per day is illus-
trated diagrammatically in Fig. 117. This is known as the Lowe
type of apparatus. Either anthracite coal or coke may be used as
fuel. The fuel is charged into the generator and allowed to under-

378

XVIII CAREURETTED WATER-GAS TAR 379

go partial combustion by admitting a limited amount of primary air
through the pipe A below the bed of fuel. The gases then pass
downward through the carbureter and the combustion almost com-
pleted by means of a carefully regulated supply of secondary air
introduced through the valve B. From the carbureter the products
pass upward through the superheater, where the temperature may
be controlled by admitting a tertiary supply of air through the valve
C ) and the products of combustion finally passed into the atmos-
phere through the stack D.

When the fuel in the gas-generator has been properly ignited,
and the carbureter and superheater brought to the required tem-
peratures, the air blasts are cut off in the sequence : C, B, and A 9 and
the stack valve D closed. Steam is introduced into the generator
through the valve E below the bed of incandescent fuel and results
in the production of "blue-gas," according to the following reaction:
C + H 2 O = CO + H 2 . This is passed into the carbureter where
it mingles with a spray of carbureting oil consisting of "gas oil" or
"fuel oil" introduced through F. The mixture is passed downward
through the carbureter whereby the oil becomes vaporized. Frorri
the carbureter, the gases are passed up through the superheater, the
temperature of which is very carefully regulated at 1200-1300 F.
to crack the oil vapors into permanent gases, and this incidentally
results in the formation of tarry matters.

The formation of carbon monoxide and hydrogen by the action
of steam on incandescent fuel results in a lowering of the tempera-
ture, on account of the absorption or storing up of thermal energy,
so that it becomes necessary to turn off the steam and reintroduce
the air. The "blowing up" process is then repeated. At the same
time the oil spray is turned off the carbureter, as its temperature has
fallen to a point below which the oil would not be superheated suffi-
ciently to convert it into a permanent gas. The "blowing" or "up
run" lasts three to five minutes, and the "gas making" or "down
run" lasts two to four minutes.

The water-gas and accompanying tarry vapors derived from
the gas oil are passed from the superheater through the pipe G into
a wash-box which corresponds to the hydraulic main in a coal-gas
plant The vaporization of water in the wash-box reduces the
temperature of the gases from 1200 to 190 F. The gases next

380 WATER-GAS AND OIL-GAS TARS AND PITCHES XVIII

pass upward through a scrubber and are then passed downward
through a water-cooled condenser which reduces their temperature
to 140-150 F., and thence into a relief gas-holder. Most of the
tar is condensed in the wash-box and smaller quantities in the scrub-
ber and condenser. An exhauster draws the gases through the fore-
going train of apparatus and then forces them through a tar extrac-
tor, to remove the last traces of tar* The temperature of the gases
as they pass through the tar extractor is in the neighborhood of
110-115 F. They are finally passed through the purifier filled
with trays of ferric oxide to remove the sulfur compounds, and
thence into the main gas holder.

The carbureting oil, known also as "gas oil" or "enriching oil"
varies in composition, depending upon the character of the petro-
leum from which it is derived. Experience demonstrates that oils ob-
tained from a paraffin-base petroleum generate the greatest propor-
tion of gas and the smallest quantity of tar. Oils containing unsatu-
rated straight-chain hydrocarbons are less efficient, and those con-
taining unsaturated ring hydrocarbons are almost valueless. The
yield of tar expressed in percentage by volume, based on the various
types of petroleum used, is as follows:

Paraffin-base naphtha 2- 4 per cent

Paraffin-base gas oil 6-10 per cent

Paraffin-base crude oil 8-12 per cent

Asphaltic-base gas oil 10-15 P er cent

Asphaltic-base crude oil 12-18 per cent

The quantity of carbureting oil ordinarily used varies from 2.5
to 4.5 gal. per 1000 cu. ft. of gas manufactured, depending upon the
statutory requirements in the territory where the gas is distributed,
as to its illuminating and heating values.

Properties of Water-Gas Tar. On account of the low specific
gravity of water-gas tar, it readily forms an emulsion with the as-
sociated water and separates with great difficulty. The water thus
retained may run as high as 85 per cent and the greater the per-
centage of water present, the more viscous will be the emulsion. 1
The water is practically free from ammonia compounds, thus differ-
ing from coal tar, and the tar is very much thinner in consistency,
containing but a small amount of free carbon. The methods for
dehydrating crude water-gas tar are similar to those used for coal

XVIII , PROPERTIES OF WATER-GAS TAR 381

tars. The dehydrated water-gas tar complies with the following
tests :

(Test i) Color in mass Black

(Test la) Homogeneity to the eye Uniform

(Test 2^) Homogeneity under microscope Absence of carbonaceous

matter

(Test 7) Specific gravity at 77 F x.oo~i.x8

(Test 8) Viscosity at 212 F. (100 cc.) 25-50

(Test i5<r) Fusmg-point (cube method) Less than o to 10 F.

(Test 1 6) Volatile matter at 50x3 F., 5 hrs 60-85 per cent

(Test 1 6) Distillation:

By weight

Up to 1 10 C. (Naphtha) o - 5 per cent (Sp. gr. o. 85-0. 90)

iio-i7oC (Light oils) 0.5- 5.0 per cent (Sp. gr. 0.88-0.90)

170-235 C. (Middle oils) 5 ~35 per cent (Sp. gr. o. 98-1 .00)

235-270 C. (Heavy oils) 7-30 per cent (Sp. gr. i .00-1 .07)

270-350 C. (Anthracene oil) . . 10 -25 per cent (Sp, gr. 1 . 07-1 . 10)
Residue (Water-gas-tar

pitch) ... 20 -70 per cent

(Test 17*) Flash-point Low

(Test 19) Fixed carbon 10-20 per cent

(Test 21) Solubility in carbon disulfide 95 -100 per cent

Non-mineral matter insoluble 0.2- 5 per cent

Mineral matter o - \ per cent

(Test 22) Carbenes o - 2 per cent

(Test 23) Solubility in 88 petroleum naphtha 20 - 75 per cent

(Test 26) Carbon 90 - 95 P^r cent

(Test 27) Hydrogen 3 - 6 per cent

(Test 28) Sulfur o. 5-2.0 per cent

(Test 29) Nitrogen o. 5-1 .o per cent

(Test 30) Oxygen i - 2 per cent

(Test 32) Naphthalene Less than 10 per cent

(Test 33) Solid paraffins o - 5 per cent

(Test 34^) Sulfonation residue i - 25 per cent

(Test 37*) Saponifiable constituents Tr. - 2 per cent

(Test 39) Diazo reaction Yes

(Test 40) Anthraquinone reaction Yes

Water-gas tars consist principally of aromatic hydrocarbons and
contain less naphthalene than coke-oven tars, negligible phenols and
bases, also small amounts of solid paraffins and considerable naph-
thalenes. According to Downs and Dean, 2 water-gas tar contains
substantial amounts of benzene, toluene, xyienes, naphthalene and
anthracene. The nitrogenous bases and phenols are absent or
nearly so. Weiss reports further that the percentage of free carbon
varies from 1.04 to 1.087 per cent, with water-gas tars ranging in
specific gravity from i. 078-1. 090.* Water-gas tar may be vulcan-
ized by heating with 5 to 8 per cent of sulfur. 4

382

WATER-GAS AND OIL-GAS TARS AND PITCHES

XVII]

Oil-gas Tars. These are manufactured from petroleum alon<
without the use of coal or coke. Several methods have been used
all embodying the same principle but differing in detail, the mosl
important of which are as follows:

Pintsch Gas. This is manufactured by spraying gas-oil derived
from petroleum in a closed retort constructed of iron or fire clay and
heated to a temperature of 900 to 1000 C. by combustion of oil,
gas or tar underneath. The shape of the retort is shown in Fig.
1 1 8. The vapors pass to the rear and thence downward and through
a lower chamber into the hydraulic main in front The gases are
passed successively through a scrubber, condenser and purifier.

O/J and Sfectm

Oilond
Steam

FIG. 1 1 8. Pintsch Gas Retort

fffiffi^"$^^
FIG. 119. -Oil-water Gas Plant.

Pintsch gas is used extensively for railroad and buoy lighting. It
may be stored in holders under a pressure of 5 to 25 atmospheres,
without suffering in illuminating power, as would prove to be the
case with most other gases adapted for lighting purposes.

About 10 per cent tar is recovered in the rintsch process, the
characteristics of which will be described under the heading "oil-gas
tar" below.

Oil-water Gas. This process is used almost exclusively on the
Pacific coast for manufacturing illuminating gas, owing to the ab-
sence of coal deposits. The installation is shown diagrammatically
in Fig. 119, and operates similar to a water-gas plant, except that
petroleum is used instead of coal or coke.

It requires about 8 to 8j^ gal of fuel oil per 1000 cu. ft of gas

XVIII REFINING OF WATER-GAS AND OIL-GAS TARS 383

(550625 B.t.u.) of which about one-fifth is required for heating
and four-fifths for gas-making. Higher temperatures are used for
cracking than is the case in the manufacture of Pintsch gas or Blau
gas, in consequence of which heavier tars are obtained, higher in
free carbon and aromatics.

Oil-water-gas tar has also been termed "fuel-oil gas tar" and
"reformed-gas tar." 5 At room temperatures it has a soft, semi-
solid to almost solid consistency. Those produced at medium tem-
peratures have a specific gravity at 60 F. of 1.15 to 1.20; insoluble
in benzol 12 to 15 per cent; sulfonation residue 2 to 5 per cent.
Those produced at high temperatures have a specific gravity at
60 F. of 1.30 to 1.35; insoluble in benzol 25 to 40 per cent; sul-
fonation residue less than 0.5 per cent.

Blau Gas. This is a further development of Pintsch gas, and is
made by cracking oil vapors at a temperature lower than in the
Pintsch process (i.e., 550 to 600 C.), but in a similar form of re-
tort. The resulting gases are first purified by passing in the usual
manner through hydraulic mains, coolers, cleaners and scrubbers to
remove the tar, which amounts to 4-6 per cent of the oil used, and
then compressed in a three- or four-stage compressor to 100 atmos-
pheres, which causes the high boiling-point constituents to liquefy
and absorb a large proportion of the non-liquefiable gases. The
excess of the latter is used for running the compressor and heating
the retorts.

The compressed Blau gas is so constituted that upon releasing
the pressure, the dissolved and liquefied constituents are evolved in
such proportions that the composition of the gaseous mixture re-
mains constant. Blau gas is used principally for marine lighting
purposes and is transported in cylinders of about I cu. ft capacity,
carrying 20 Ib. of the compressed gas, which will expand to about
250 cu. ft at atmospheric pressure. Its illuminating value is
greater than that of Pintsch gas.

The tar recovered from the Blau gas process (about 1520
per cent), is similar in its physical and chemical properties to the
oil-gas tars described previously. 6

Properties of Oil-gas Tars. Dehydrated oil-gas tars produced
by the Pintsch process, the Blau gas process, and the oil-water gas
process comply with the characteristics given on the following page*

Oil-gas tar may be vulcanized by heating with sulfur, 7 or by
treating with sulfur dichloride. 8

Refining of Water-gas and Oil-gas Tars. Oil-gas and water-
gas tars when suitably dehydrated may be distilled in accordance
with the methods used for "coal tar." Sometimes, either water-gas-

384

WATER-GAS AND OIL-GAS TARS AND PITCHES

XVIII

Oil-gas Tars

Low Temperature
(Pintsch- and Blau-
gas Tars)

I
High Temperature
(Oil-water-gas Tars)

(Test i) Color in mass. *

Black

Uniform
Comparatively free
from carbonaceous
matter.
0,95-1,10
25-50
o

Black
Gritty
Contains consider-
able carbonaceous
matter.

i.iS-i-35
Over 50
o to 5

30-100 F.

(Test id) Homogeneity to the eye

(Test 2^) Homogeneity under microscope.

(Test 7) Specific gravity at 77 F

(Test 8*) Viscosity at 212 F. (100 ml.)

(Test 9*:) Consistency at 77 F

(Test 15^) Fusing-point (R. & B, method)

(Test 15^) Fusing-point (Cube method) . . .*

<0-20F.

35-70 per cent
30-75 per cent

(Test 1 6) Volatile at 500 F. in 5 hrs. . .

25-50 per cent

20-50 per cent
1.05-1.12
50-80 per cent
ioo-i5oC.
Low
15-35 percent
70-90 per cent
10-30 per cent
0-0.5 per cent
0-2 per cent
25-70 per cent
< i per cent
1-2 per cent
0-5 per cent
Trace
Trace to 10 per cent
Trace
Yes (marked)
Yes

(Test 1 6b) Distillation Test:
Distillate to 315 C. (vol.)

Sp. gr. ditto at 6o/6o C

Residue at 31 5 C. (wt.)

25-70 per cent

Fusing-point ditto (R. & B. method) .
(Test 170) Flash-point . ,

Low

10-25 per cent
99-100 per cent
0-0.2 per cent
0-0.5 per cent
0-2 per cent
50-85 per cent
< i per cent
1-2 per cent
Trace
0-5 per cent
20-40 per cent
Trace
Yes (slight)
Yes

(Test 19) Fixed carbon

(Test 2i) Soluble in carbon disulfide

Non-mineral matter insoluble ........

Mineral matter

(Test 22) Carbenes

(Test 23) Soluble in 88 petroleum naphtha
(Test 28) Sulfur

(Test 30) Oxygen . . . *

(Test 32) Naphthalene

(Test 33) Solid paraffins

(Test 34^) Sulfonation residue

(Test 37*) Saponifiable constituents

(Test 39) Diazo reaction

(Test 40) Anthraouinone reaction

tar pitch or oil-gas-tar pitch is mixed with coal-tar pitch in suitable
proportions.

Properties of Water-gas-tar Pitch and Qil-gas-tar Pitch. Water-
gar-tar and oil-gas-tar pitches may be distinguished from coal-tar
pitches by:

(1) The small percentage of "free carbon" (non-mineral mat-
ter insoluble in carbon disulfide).

(2) The possible presence of paraffin wax (when non-asphaltic
or semi-a&phaltic petroleums are used).

On the other hand, water-gas-tar pitch may be distinguished
from oil-gas-tar pitch by the following:

XVIII WATER-GAS-TAR PITCH AND OIL-GAS-TAR PITCH

385

1 I ) Lower specific gravity of water-gas-tar pitch.

(2) Larger percentage of sulfonation residue from oil-gas-tar
pitch. The sulfonated constituents are soluble in water, which
serves to differentiate them from lignite- and shale-tars and pitches.

Water-gas-tar and oil-gas-tar pitches comply with the following
tests :

Water-gas-tar
Pitch

Oil-gas-tar
Pitch

(Test |} Color in mass .

Black
Uniform
Small amount o
Variable
Conchoidal
Bright
Black
1.10-1.25

O-IOO
>IQO

Variable
Variable
80-275 F.
100-300 F.
110-320 F.

5-i5
300-400 F.

25-45
75-98
2-25
o-*

5-10

50-70

<4
0-2

0-5
0-15

O-I

Yes (*)
Yes

Black
Uniform
f carbon visible
Variable
Conchoidal
Bright
Black
I.I5-I-35

O-IOO
>IOO

Variable
Variable
80-275 F.
100-300 F.
i 10-320 F,
5-15
300-400 F.
20-35
70-98
2-30
o~i
5-10

60-80
<4

O-2

0-5
20-40

O-I

Yes (*)
Yes

(Test 20) Homogeneity to the eye

(Test 2^) Homogeneity under the microscope

(Test 4) Fracture

(Test 5) Lustre

(Test 6) Streak

nVt V\ Snecific crravitv at *77 F

(Test 9^) Penetration at 77 F i . .

(Test (\\ Susceptibility index

(Test 10) Ductility

(Test n) Tensile strength at 77 F

(Test 1 50) Fusing-point (K. and S. method)

(Test i$b) Fusing-point (R. and B. method)

(Test i 5^) Fusing-point (cube method)

(Test 1 6) Volatile matter 500 F., 5 hrs. (per cent) . .
(Test 170) Flash-point

(Test 19) Fixed carbon (per cent)

(Test 21) Solubility in carbon disulfide (per cent)
Non-mineral matter insoluble (per cent)
Mineral matter (per cent) ...,.,,,,,,

(Test 22) Carbencs (per cont) .

(Test 23) Solubility in 88 petroleum naphtha (per
cent)

(Test 28) Sulfur (per cent)

rryjt -30^ Oxvcren (oer cent}

(Test 33) Solid paraffins (per cent)

(Test 34^) Sulfonation residue (per cent) ............

(Test 37^) Saponifiable matter (per cent)

(Test **(\\ Diazo reaction ......... , ,

(Test 40) Anthratjuinone reaction ............ r , n r -

Slight contain but a trace of phenols.

Both of these pitches are largely susceptible to changes in tem-
perature, they are highly resistant to the prolonged action of mois-
ture, and they are adapted for manufacturing low-priced solvent
paints because of their ready solubility in "coal-tar naphtha/'

CHAPTER XIX
FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH

These are classified together because all are derived from sub-
stances containing animal or vegetable fats or oils, although in
manufacturing bone tar and bone-tar pitch the crude materials carry
but a small proportion.

FATTY-ACID PITCH

Various generic terms have been used to designate this prod-
uct, including candle tar, "Kerzenteer" (German) "goudron"
(French), candle pitch, fat pitch and "Fettpech" (German). Spe-
cific names have also been applied, descriptive of the raw materials
used in producing the pitch, such as stearin pitch, palm-oil pitch,
bone-fat pitch, cotton-seed-oil pitch, cotton pitch, cotton-stearin
pitch, cotton-seed-foots pitch, corn-oil pitch, corn-oil-foots pitch,
packing-house pitch, garbage pitch, sewage pitch, fullerVgrease
pitch, wool pitch, wool-grease pitch, wool-fat pitch, cholesterol
pitch, cotton-oil pitch, cotton-seed-oil-foots pitch and stearin-wool
pitch.

The fatty-acid pitches are obtained as by-products in the follow-
ing manufacturing processes :

( i ) Production of candle and soap stocks.

(2) Refining vegetable oils by means of alkalies.

(3) Refining refuse greases.

(4) Treatment of wool grease.

The raw materials used include the vegetable oils and fats, ani-
mal oils, fats and waxes (wool grease), also the waste greases de-
rived from the foregoing. Vegetable and animal fats and oils are
combinations of the fatty acids with glycerin, known as "triglycer-
ides," and illustrated by the following generic formula, in which "R"
represents any fatty acid radicle:

C 3 H 5 eOR
N OR

XIX FATTY-ACID PITCH 387

Fats and oils may be purified or refined in two ways :

(1) By treating vegetable oils with a small amount of caustic
soda to remove the coloring matter, free fatty acids and other im-
purities, without, however, breaking up the triglycerides. This
process is used for refining vegetable oils when they are to be used
for edible purposes. The residue is treated with mineral acid to
break up the soaps, and then distilled with steam to recover the
fatty acids, whereupon a residue of fatty-acid pitch is obtained.

(2) By decomposing or "hydrolyzing" the triglycerides into
glycerin and free) fatty acids, and then distilling the latter with
steam, whereby fatty-acid pitch is obtained as a residue. The object
of distilling the fatty acids is to improve their color or odor and
thereby adapt same (a} for the manufacture of candles (which are
commonly light-colored or white), or (b] for manufacturing soaps
(such as toilet soaps, etc.) which must be odorless and preferably
light-colored.

Production of Candle and Soap Stocks. These are obtained
from various animal and vegetable oils and fats, also from waste
greases. It is always necessary to subject the fatty acids to a proc-
ess of hydrolysis and steam distillation for producing candles, but
not for manufacturing soaps, unless the fatty acids are too dark in
color for the character of soap required or possess a disagreeable
odor, in which event they are purified by distillation. Various
methods of hydrolysis may be used, but they all depend upon the
same reaction, in which the triglyceride combines with water and
decomposes into glycerin and fatty acids, as illustrated in the fol-
lowing equation:

OR OH

-OH

C 3 H 5 A)R + 3H-OH - CaHsf-OH + jR-OH
fc>OR X OH

Triglyceride Water Glycerin Free Fatty Acid

(fat or oil)

It is necessary to hydrolyze the fats or oils before distilling the
fatty acids, since the triglycerides themselves are not capable of be-
ing distilled without decomposition. The following methods of
hydrolysis have been used:

(a) Hydrolysis by Means of Water. Formerly, water alone
was used for the purpose, the fat or oil being heated in an autoclave
with 30 per cent of its weight of water at 220 Ib. pressure (corre-
sponding to a temperature of 200 C.) for eight to twelve hours.

388 FATTY-ACW PITCH, BONE TAR AND BONE-TAR PITCH XIX

This decomposes the triglyceride into fatty acids and glycerin, but
with water alone it is difficult to break down the fat completely.
It has been found that the addition of 3 per cent of lime or mag-
nesium oxide, and preferably the latter, assists the reaction and
produces a larger yield of a better product, and at a much lower
temperature. Accordingly, the fat or oil is heated at 120 Ib. pres-
sure in a horizontal or vertical cylindrical vessel provided with
a stirring device, with 20 to 25 per cent by weight of water and
3 per cent of lime or magnesium oxide. The breaking down of
the fat is practically complete at the end of eight to ten hours, and
in addition the color is very much better, as there is less decom-
position, due to the lower temperature employed. The fats or oils
used for this purpose may consist of animal or vegetable tallow,
palm oil, bone fat, lard- or cotton-seed stearin (crystallized at low
temperatures from lard or cotton-seed oil respectively), shea butter,
etc.

At the end of the process, the free fatty acids rise to the sur-
face and are skimmed off, leaving the aqueous liquor containing the
glycerin (together with the hydrated lime or magnesia, when the
Fatter are used). The glycerin is recovered by a special process
which, however, does not fall within the scope or this treatise. The
fatty acids are subjected to steam distillation to deodorize and
whiten them, also to purify them by separating any non-hydrolyzed
fat The fatty acids are run into lead-lined tanks w r here they are
first treated with dilute sulfuric acid to remove any traces of mag-
nesium oxide, etc., then washed with water, heated to expel the
moisture, after which they are fed into a retort and distilled with
superheated steam with or without the use of vacuum. The fatty
acids suitable for distillation should not contain more than 5 per
cent of non-hydrolyzed fat (neutral fat) nor more than 0.2 per cent
of mineral matter. To obtain a distillate of good quality, care
should be taken not to distil the fatty acids at too high a tempera-
ture, as they are extremely susceptible to overheating and decom-
position into dark-colored hydrocarbons (unsaponifiable), which
would, of course, depreciate the value of the product. 1 The still
should be constructed so that the flames will not come into direct
contact with the bottom and cause local overheating. The tem-
perature of the material in the still should preferably be maintained
between 230 and 250 C, and although in certain instances it is
permissible to reach a temperature of 270 C., under no circum-
stances should this be exceeded.

Two methods are used for conducting the distillation. The
first consists in continuously replacing the tatty acids as they distil,
with an equivalent quantity of undistilled material, as long as the
distillate snows a satisfactory color and is free from unsaponifiable

XIX

FATTY-ACW PITCH

389

hydrocarbons. The effect of the distillation is to concentrate the
impurities and unsaponified (neutral) fats or oils in the still. A
typical installation is illustrated in Fig. I20. 2

The heating element in the still, a, consists of two copper coils
of approximately 270 square feet (25 square meters) mean sur-
face. Steam at about 450 pounds per square inch (32 kg. per
sq. cm. ) gage pressure is supplied by a motor-driven compressor, b.
Vacuum is maintained at 7 to 10 mm, of mercury by use of steam
ejectors, c. Approximately 10,000 pounds (4536 kg.) of crude
fatty acid are charged to the still at the start of a run, and there-

To Primary

Evacuating

System

FIG. 120. Distillation of Fatty Acids.

after for about 20 hours the feed is continuous to maintain an even
level. The crude stock going to the still is preheated by passing
through a heat exchanger, d, which also serves as a partial con-
denser for the fatty acid vapors. Most of the distillate is con-
densed in the jacketed coolers, e. A small amount of stock is con-
densed and baffled out in separator / and measured in receiver g.
The bulk of the distillate is received in h and pumped out, under
vacuum, to storage. The residue in the still a consists of soft fatty-
aqid pitch.

The second method consists in replacing the distilled fatty acids
for but sixteen to twenty-four hours, then discontinuing the addi-

390 FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH XIX

tion, and distilling the contents of the retort until the distillate
ceases to be of suitable quality, as is evidenced by a change in its
color. The residue consisting of soft fatty-acid pitch is then drawn
off into a separate still known as the 4< pitch still," the first still
recharged, and the process repeated, until after a sufficient number
of distillations, a sufficient quantity of soft fatty-acid pitch accu-
mulates for further treatment. It is claimed that the second
method gives better results and yields a distillate lighter in color,
containing a smaller percentage of hydrocarbons.

In either case the soft residue is distilled separately with super-
heated steam and vacuum. When the neutral fats increase in con-
centration to 12 to 15 per cent they commence to decompose into
hydrocarbons, some of which distil with the fatty acids and some re-
maining with the residue. On distillation, the saturated fatty-acids
pass over first and the residue contains an increasing proportion of
unsaturated and hydroxy-acids, such as hydroxy-stearic acid, which
at higher temperatures is converted into iso-oleic acid. At still
higher temperatures the fatty acids are converted into hydro-car-
bons, which are principally unsaturated. The final residue consti-
tutes the so-called "fatty-acid pitch" which amounts to between 2.5
and 5 per cent of the fatty-acids distilled.

(b) Hydrolysis by Means of Concentrated Sulfuric Acid? The
fats or oils are first freed from moisture by heating to a tempera-
ture of 120 C. It is essential that all the moisture be removed to
prevent excessive decomposition. The mass is then rapidly mixed
with 4 to 6 per cent of concentrated sulfuric acid (66 to 67 Be.)
and heated in a cylindrical vessel provided with a mechanical agi-
tator. The heating is continued just long enough to break up the
triglycerides and no longer. The sulfonated mass is then imme-
diately run into boiling water and agitated by a steam jet until the
sulfonated acids hydrolyze. The mass is then allowed to stand
quietly until the free fatty acids rise to the surface, leaving the
glycerol and sulfuric acid in the lower layer.

The fatty acids produced in this manner are dark colored and
must be distilled. They are first washed with water until neutral,
then heated to expel the moisture and finally distilled with super-
heated steam, with or without a vacuum as previously described,
whereupon a residue of soft fatty-acid pitch is obtained. According
to modern practice, this residue is again treated with concentrated
sulfuric acid to hydrolyze any neutral fats remaining, and inci-
dentally remove the accumulated mineral matter (including any
copper or iron derived from the stills). It is then washed free from
the acid and redistilled, leaving a residue of medium to hard fatty-
add pitch. The dark-colored distillate, known as "still returns,"

XVIII FATTY-ACID PITCH 391

is worked up in small quantities with the crude fatty acids under
going their first distillation.

The yield of stearin known in this case as "distillation stearin"
is greater than that obtained in the aqueous process of hydrolysis,
due to the fact that some of the olein (in this case known as "dis-
tillation olein" or "distilled olein") is converted into a solid prod-
uct (consisting of stearolactone, isomeric oleic acid, etc.). The
olein and stearin are separated by cooling, exactly as in the fore-
going process, A smaller yield of glycerin is obtained due to its
partial decomposition by the acid, and that of fatty-acid pitch is
also less and of a darker color.

To avoid losing the glycerin, which constitutes one of the most
important and highest priced products, a "mixed process" is now
used consisting of a combination of the foregoing. ^

(c) Hydrolysis by the "Mixed Process" This is a combina-
tion of the two foregoing processes, and consists in first hydrolyz-
ing the fats or oils in an autoclave with water and an alkaline accel-
erating agent (such as lime or magnesium oxide), and in this way
recovering the full amount of glycerin. The resulting fatty ^ acids
are dehydrated and treated with concentrated sulfuric acid in ac-
cordance with process (b) to increase the yield of stearin and com-
plete the hydrolysis of any neutral fat which may have escaped the
first treatment, and thus minimize the formation of hydrocarbons
in the distillate,

(d) Hydrolysis by Means of Sulfo-compounds. This process,
known as the E. Twitchell method, is rapidly replacing the others,
and is now employed in soap factories for treating the fats or oils
before soap-making, as it separates a purer glycerin and at the same
time results in a greater yield (88 to 90 per cent of the theoretical
quantity contained in the fat or oil w. 80 to 84. per cent obtained
in the direct caustic soda saponification method for soaps). More-
over, the liquor separated in the Twitchell process is not contami-
nated with the sodium chloride used for "salting out" the soap in
the ordinary method, and it contains 15 per cent by weight of gly-
cerin against 3 to 4 per cent in the liquor obtained on direct saponi-
fication of the fats or oils with sodium hydroxide. The former
therefore effects a saving in evaporation.

The fat or oil is first purified by steaming with I per cent of
60 Be, sulfuric acid for about two hours. It is then transferred
to a wooden vessel equipped with perforated steam pipes, also a
well-fitting cover to exclude air which would cause the fatty acids
to darken, and mixed with 50 per cent water and 1.5 per cent of the
Twitchell reagent The latter is prepared by allowing an excess of
sulfuric acid to act on a solution of naphthalene (or other aro-

392 FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH XIX

matic hydrocarbon) in oleic acid, which results in the production
of a body having the general composition:

/SOaH
6 <
X

CioHe

Naphthalene-sulf o-stearic acid.

It is advisable to introduce a small percentage of free fatty acids
to start the hydrolysis which otherwise takes a little time to begin.
The material is steamed for twenty-four hours, whereupon a small
quantity (o.i to 0.2 per cent) of 60 Be. sulfuric acid is added to
break up the emulsion and permit the fatty acids to rise to the sur-
face and the glycerol to pass into the aqueous liquor below. About
0.05 per cent of barium carbonate is finally added to neutralize the
mineral acid.

The resulting fatty acids are dark in color and must be distilled.
This is usually affected after a preliminary treatment with concen-
trated sulfuric acid as in method (b) to increase the yield of stearin,
which is of special importance when the product is to be used for
manufacturing candles. The yield is the same as obtained from
the saponification or mixed process respectively, depending upon
the exact method of treatment.

(e] Hydrolysis by Means of Ferments. This method is also
meeting with some favor, as it produces a large yield of glycerin
uncontaminated with salt or other solids difficult of separation.
Many soap manufacturers accordingly hydrolyze their stock by
means of ferments to separate the glycerin, and then saponify the
resulting fatty acids with sodium carbonate, either directly, or after
first purifying them by steam distillation.

The ferment is derived from the castor plant by grinding the
decorticated castor beans with water and filtering through cloth,
whereupon a white creamy filtrate is obtained which is set to one
side and allowed to ferment spontaneously. The ferment which
rises to the surface is skimmed off and used while fresh. It is com-
posed of a thick creamy substance containing approximately 38 per
cent of fatty acids derived from castor oil, $8 per cent of water and
4 per cent of an albuminoid substance containing the active material.

The fat or oil to be treated is mixed with 40 per cent water, 5
to 8 per cent of the ferment and 0.2 per cent of manganese sulfate
in a lead-lined vessel equipped with a steam coil and a perforated
compressed-air pipe. Heat is then turned on, and the temperature
maintained 2 to 3 C. above the melting-point of the fat or oil.
The mass is agitated by air introduced through the perforated pipe
and the treatment continued one to three days until the hydrolysis

XIX FATTY-ACID PITCH 393

is complete. Sufficient steam is then turned on to bring the mass
to a temperature of 80 to 85 C, whereupon 0.30 to 0.45 per cent
of 50 per cent of sulfuric acid is stirred in by air. This breaks up
the emulsion, the clear fatty acids rising to the top and the aqueous
liquor containing the glycerin settling to the bottom.

When the separated fatty acids are pale in color they may be
saponified directly for manufacturing soaps. Where dark-colored
fats, oils or greases have been employed, which result in the produc-
tion of dark-colored fatty acids, the mass is distilled with steam,
whereupon the fatty-acid pitch is obtained as residue. Candle stock
may also be produced by subjecting the purified fatty acids to a low
temperature and filtering, as described previously.

It is, of course, understood that when the crude oils or fats (tri-
glycerides) or the free fatty acids derived from them (by any of
the foregoing processes of hydrolysis) are saponified directly with
sodium carbonate (soda ash), no fatty-acid pitch is produced.

Refining Vegetable Oils by Means of Alkali. Most vegetable
oils intended for edible purposes, whether they are to be used for
salad oils, lard substitutes, margarine manufacture, or directly for
cooking oils and shortening, are first treated with caustic soda for
the purpose of removing free acids, coloring matter, albuminous
material, resins, etc. The oils chiefly treated are cotton-seed, corn,
soya bean, cocoanut and peanut oils.

(a) Refining Cotton-seed Oil. Crude cotton-seed oil when
obtained fresh from the seed varies in color from reddish brown to
almost black. This is due in part to the coloring matter, which is
a dark resinous substance capable of combining with caustic soda,
forming a water-soluble salt, also albumin and pectin bodies. The
method of refining the oil consists in agitating it with varying quan-
tities of caustic soda solution, the strength of which will range from
i.io to i. 20 specific gravity, according to the percentage of free
fatty acids present and the practice of the individual refiner. The
agitation is effected by mechanical stirrers in large tanks provided
with heating coils. The quantity of alkaline liquor added is deter-
mined by careful laboratory tests and run in through perforated
pipes. The effect of the alkali is first to darken the oil and appar-
ently thicken it. After a short time small flakes begin to separate
and heat is then applied. As the temperature increases, the flakes
become larger, owing to the soap softening and running together.
When the right point is reached, at temperatures varying from 100
to 130 R, steam and agitation are shut off and the soap drops to
the bottom of the kettle, forming a mucilaginous mass, varying in

394 FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH XIX

color from yellow to brown, through all shades of green and red.
This material is known as the "foots." The clear light yellow oil
which is pumped off the foots is then refined further for edible pur-
poses. Cotton-seed oil purified in this manner is known to the
trade as "summer yellow oil/* When used in making lard substi-
tutes it is bleached with fuller's earth and then deodorized, gen-
erally by the use of steam. Salad oil is obtained by chilling the
summer yellow oil s& as to crystallize out the palmitin which is
separated by pressing or filtering.

In the United States alone the annual production of cotton-seed
foots amounts to approximately half a million barrels. The foots
vary in gravity from 0.97 to 1.04, averaging about i.oo. They con-
tain the soda salts of the coloring matter, the soda soaps of any free
fatty acids present in the cotton-seed oil (30 to 45 per cent), the
coagulated albumin (8 to 12 per cent), phytosteryl, and varying
quantities of mechanically entrained cotton-seed oil (triglycerides).

Cotton-seed foots are sold on the basis of "50 per cent fatty
acid." As a matter of fact they contain between 35 and 65 per
cent, averaging about 45 per cent. A representative sample con-
tained : *

Fatty anhydrides (corresponding to a "5o-per cent soap stock") 48. 50 per cent

Glycerin 3-98 per cent

Caustic soda (NaaO). 3- 20 per cent

Foreign organic matter 5- 9 per cent

Coloring matter 2.41 per cent

Water 36.00 per cent

Total * 100. oo per cent

The cotton-seed foots may be converted directly into soap by
boiling up with a small excess of caustic soda and "salting" it put
in the usual manner, when no pitch will be obtained. The resulting
soap is known as "killed foots" and the dark lye containing the
coloring matter and impurities are run to waste. A process has also
been described for recovering a shellac-like substance from cotton-
seed foots by oxidizing with hydrogen peroxide in an alkaline solu-
tion and acidifying to separate the fatty matter. 5

Usually, however, the cotton-seed foots are subjected to distilla-
tion. They are first boiled with sufficient alkali to complete the
saponification and then treated with mineral acid to liberate the
fatty acids. Or the foots may be acidified while hot with dilute
sulfuric acid, whereupon a "black grease" containing about 90 per
cent of the total fatty acids (calculated as oleic) rises to the sur-
face. This is separated and subjected to the Twitchell or other
hydrolyzing processes to break up any neutral fat and recover all

XIX FATTY-ACID PITCH 395

the glycerin. The fatty acids obtained in this manner are equiva-
lent to 7,5 to 8.5 per cent of the original weight of the cotton-seed

011 used. They are subjected to vacuum distillation with super-
heated steam to separate the pure fatty acids from the residue of
fatty-acid pitch, variously called "cotton pitch," "cotton-oil pitch/'
" cotton-seed-oil pitch," "cotton-stearin pitch," "cotton-seed-oil-foots
pitch," etc. The quantity of pitch produced will range between 10
and 20 per cent of the weight of the crude fatty acids (black
grease) distilled, which is equivalent to i to 2 per cent by weight
of the original cotton-seed oil. The yield will depend upon the
degree the oil is saponified, the amount of impurities present, the
efficiency of the distilling apparatus and the extent to which the dis-
tillation is carried. The still generally used holds 3 to 5 tons and
the distillation is conducted intermittently. Two types of conden-
sers are used, viz.: (i) water-cooled and (2) air-cooled. From
these the vapors are passed through another condenser in which a
water spray removes the lower fatty acids. Any volatile fatty acids
distil over first, followed by the free fatty acids of higher boiling-
points. The decomposition of any neutral fat present into unsat-
urated hydrocarbons and unsaturated fatty acids does not com-
mence until the concentration of the neutral fat in the still reaches

12 to 15 per cent

The purified fatty acids recovered by distillation are used for
manufacturing soaps. The fatty-acid pitch is usually soft in con-
sistency, moderately stringy and of a pale brown color when exam-
ined by transmitted light in thin layers.

(b) Refining Corn Oil. Corn oil is sometimes refined by treat-
ing with a small proportion of caustic soda in a manner similar to
the method described for cotton-seed oil. Upon deodorizing the re-
fined product with superheated steam under reduced pressure, while
heated to a temperature of 400 F,, an edible product is obtained,
used as a salad oil, also for cake and biscuit making. It may also
be converted into a lard compound by a hydrogenation process.
The corn-oil foots are treated by a method similar to the one used
for refining cotton-seed foots. A pitch is obtained known as "corn-
oil pitch," possessing a comparatively high fusing-point, character-
ized by its rubber-like properties and lack of ductility. If the dis-
tillation is carried too far, the pitch will actually solidify in the still
and can only be removed with great difficulty.

Refining Refuse Greases, (a) Refining Packing-house and
Carcass-rendering Greases. "Tallow" is the name applied to the
purified solid fat or "suet" obtained from cattle. It is used ex-
tensively for producing soap and candle stock. The crude fat is
first "rendered" by boiling with water in an open vessel to separate

396 FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH XIX

it from any albuminous matter or other impurities present, and then
clarified by washing with weak brine. "Lard" is obtained by ren-
dering the soft fats which surround the kidneys, intestines and backs
of pigs. Tallow and lard may be used as such for manufacturing
soaps, but for producing candles they must first be hydrolyzed and
purified by steam-distillation.

The waste meat scraps obtained from packing houses, also the
carcasses of animals freed from the bones, are treated with steam in
large digestors at a high pressure to separate the fat. When the
cooking is complete, the batch is allowed to stand quietly to permit
the grease to rise to the surface and the disintegrated meat-fibers
to settle. The grease is skimmed off and mixed with any additional
grease recovered from the settlings by filter-pressing. The residue
is then converted into fertilizer, and the aqueous liquid used for
making glue. The grease recovered from this process has a dis-
agreeable odor and a dark color, and must be hydrolyzed and steam-
distilled before it can be used for manufacturing either candles or
soap. The residue from the steam distillation process, amounting
to between 5 and 6 per cent of the grease, constitutes a variety of
fatty-acid pitch having a light brown color when viewed in a thin
layer and great ductility (unless the pitch is distilled too far). A
packing-house grease has been extensively marketed in this country
under the name of "yellow grease."

(b) Refining Bone Grease. The bones recovered from pack-
ing houses or carcass-rendering works are used for manufacturing
glue, bone-black (used for decolorizing petroleum distillates), and
fertilizer. Bones from the head, ribs and shoulder-blades contain
12 to 13 per cent of fat, whereas the large thigh bones ("mar-
rows") contain 20 per cent. The fat is extracted by breaking up
the bones into small fragments and then either:

1 i ) Treating with steam in an autoclave under a pressure of
2 to 3 atmospheres, whereupon a portion of the fat separates and
floats to the surface, the gelatin or glue goes into solution, and the
mineral ingredients (calcium phosphate, etc.) remain as residue.
From 8 to 9 per cent of fat (based on the dry weight of the bones)
is recovered in this manner.

(2) Extracting the dried bones with a volatile solvent such as
naphtha, carbon tetrachloride, or benzol in a suitable apparatus. . A
much higher percentage of fat is extracted in this manner, but the
cost of operation is higher, due to unavoidable losses of solvent, and
the odor of the product is very strong.

In either event the extracted bone fat is first hydrolyzed by any
of the foregoing methods and then steam-distilled, whereupon a
variety of fatty-acid pitch, known as "bone-fat pitch," is recovered
as residue, amounting to 5 to 6 per cent by weight of the bone-fat.

XIX FATTY-ACID PITCH 397

The product may be used for manufacturing soap, or after cooling
and filtering, the "stearin" may be converted into candles, and the
"olein" either used for manufacturing soap or else marketed as
such for "wool oils."

Water 70-80 per cent

Grease 3- 4 per cent

Tankage 10-20 per cent

Tailings (rubbish) , 3- 6 per cent

. It is treated in a manner similar to that used for working up the
refuse from packing houses and carcass-rendering establishments,
namely by boiling in large digesters holding 8 tons for six hours
under a pressure of 70 to 80 Ib. (Arnold-Egerton System), 6 This
reduces the material to a pulpy mass, which is filter-pressed to re-
move the water and grease. The residue, known as "tankage," is
dried and ground for use as fertilizer. The filtrate is allowed to
stand, whereupon the grease rises to the surface and is skimmed off.
The grease, when dehydrated, has a dark brown color. It is hydro-
lyzed to separate the glycerin, and the resulting fatty acids purified
by steam-distillation to render them suitable for manufacturing soaps
and candles. The residue, known as "garbage pitch," amounting
to 5 to 7 per cent by weight of the garbage, has a dark color when
viewed in a thin layer, and is quite susceptible to temperature
changes.

Sewage also carries a proportion of grease which is now often
being recovered, especially in large cities. The sewage is first run
into large tanks, where the solid matter known as "sludge" settles
to the bottom. The precipitation may be accelerated by adding a
small percentage of slaked lime. After drawing off the liquor, the
sludge is treated with a small quantity of sulruric acid to break
up any insoluble soaps, and then boiled in large digestors under
pressure to hydrolyze the fats, and enable the grease to separate.
The residue is dried and used as fertilizer. The grease is dehy-
drated, then hydrolyzed and finally distilled with superheated steam,
yielding about 25 per cent of a fatty-acid pitch known as "sewage
pitch." The characteristics of this are similar to those of garbage
pitch. The distillate contains about 50 per cent of liquid olein and
50 per cent of solid stearin melting at about 113 F. 7

(d) Refining Woolen-mill Waste. Olive oil, lard oil, neat's-
foot oil, saponification olein (or saponified olein) and distillation
olein (or distilled olein) are sold under the names "wool oils" or
"cloth oils," and used in woolen mills for lubricating the wool be-
fore spinning into yarn, or for oiling old woolen rags before grind-

398 FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH XIX

ing and "pulling** in the manufacture of "shoddy/' One of the
perquisites of the wool oils is that they shall have no tendency to
dry or oxidize, and they must also be easily removable on boiling
the finished woolen goods or shoddy with a solution of soap or so-
dium carbonate. The presence of hydrocarbons, even in small quan-
tities, is objectionable, as they tend to prevent the removal of the
wool oils during the scouring process.

After the goods are scoured, the liquid is mixed with freshly
slaked lime which serves to precipitate the soaps. The curds are
settled out and separated, then acidified with dilute sulfuric acid
to separate the free fatty acids, which are skimmed off and filtered
to remove any dirt. The product known as "fuller's grease," "seek
oil," or "magma oil/* is distilled with steam, whereby the wool oils
are recovered, and a residue of fatty-acid pitch obtained, amounting
to to per cent by weight of the grease; known as "fuller's-grease
pitch," or "seek-oil pitch." This will vary in its properties depend-
ing upon the raw materials entering into the composition of the
original wool oils.

Treatment of Wool Grease. Wool grease, known also as
"wool wax," or "wool degras," represents the oily material natur-
ally present in sheep's wool, and differs entirely from the so-called
"wool oil" discussed previously. Wool grease is in reality an ani-
mal wax, as it contains no glycerin or glycerides whatsoever. It is
extracted by boiling the cut wool with an alkaline soap solution or
sodium carbonate. Formerly, volatile solvents were used for this
purpose, but the method is no longer practiced. After boiling with
soap or sodium carbonate, the liquor is acidified with sulfuric acid,
whereupon grease rises to the surface and is skimmed off. Dehy-
drated wool grease melts between 86 and 104 F. and contains ap-
proximately 55-60 per cent fatty acids, also 40-45 per cent higher
alcohols ( unsaponifiable ) .

Wool grease is treated in various ways, and among others by a
direct process of distillation with superheated steam without pre-
vious hydrolysis (as the waxes present are not amenable to such
treatment) whereby the following reactions take place: 8 (i) dis-
tillation of the free fatty acids, which continues up to one-third of
the distillate; (2) decomposition of free hydroxy acids principally
into lactones, some of which distil over and some decomposing into
carbon dioxide and solid unsaturated acids; (3) decomposition of
neutral esters into unsaturated acids and unsaturated hydrocarbons.

XIX FATTY-ACID PITCH 398

Since wool grease contains an average of 65 per cent esters, this
will account for the high percentage of unsaponifiable matter in
wool grease products ; (4) distillation of hydrocarbons. About 39
per cent of the total fatty acids in wool grease is oxidized acids, and
of these about 25 per cent work their way into the distillate and the
remainder are found in the residual pitch. The pitch consists of
about 85 per cent polymerized hydrocarbons and 12 to 15 per cent
fatty acids (of which 40 to 65 per cent are oxidized acids). The
course of the treatment is shown in Table XXVII. The residue of
fatty-acid pitch is known as "wool-grease pitch," "wool-fat pitch,"
"wool pitch," or "cholesterol pitch." The olein (known as "dis-
tilled-grease olein" or "degras oil"), is used as a leather or wool
oil, and the stearin (known as "degras stearin"), is used in the
soap industry or as a leather "stuffing grease."

TABLE XXVII

Wool Grease
(distilled)

Gas oil
(distilled or
marketed)

Pale distillate
(cold pressed)

4 4
Back ends Pitch
(distilled 01 (left in the
marketed) still)

1
Olein
(redistilled)

1 -
(cold pressed)

(he

4
Stearin
t pressed) or (redistilled)

(cold pressed, then
hot pressed)

4
Pale olein
(marketed)

4 i
Stearin Stearin 1
(marketed) (marketed)

i i

Hot-pressed 4 4
Olein Hot-pressed Stearin
(marketed Olein (marketed)
or redis- (marketed
tilled) or redis*
tilled)

Physical and Chemical Properties of Fatty-acid Pitches.
Fatty-acid pitches vary considerably in their physical and chemical
properties, depending upon the following circumstances : 9

1 i ) The nature of the fat or oil from which the fatty acids are
derived. If these contain low melting-point fatty acids, the fatty-
acid pitch will be soft in consistency, provided the distillation has
not been carried too far. On the other hand, if high melting-point
fatty acids predominate, the fatty-acid pitch will be semi-solid to
solid in consistency.

(2) The proportion of neutral fats or oils present in the fatty-

400 FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH XIX

acid mixture, which will prove substantial if the process of hy-
drolysis is not carried to theoretical completion. Since the neutral
fats or oils (triglycerides) do not distil with superheated steam,
they concentrate in the fatty-acid pitch, and are very apt to decom-
pose into hydrocarbons (unsaponifiable) if the distillation is carried
too far. If the distillation is stopped at a point without decom-
posing the neutral fats or oils, the value of the fatty-acid pitch is
enhanced by their presence, as they are more stable and weather-
resistant than the fatty acids themselves.

(3) The extent to which the distillation is carried and the
temperature at which it is performed. If distilled too far or at too
high a temperature, the fatty acids decompose in the presence of
steam, first into hydroxy acids, which in turn break down into lac-
tides, unsaturated products and lactones in the following manner:

(a) -hydroxy acids are converted into lactides.

(b) jS-hydroxy acids become converted into unsaturated
products.

It follows, therefore, that the fatty-acid pitches contain free
fatty acids (mostly polymerized), their lactones (anhydrides), un-
decomposed glycerides (neutral fats or oils), condensation products
of unknown composition, hydrocarbon decomposition products, and
in the case of fatty-acid pitches derived from wool grease, we find
cholesterol and higher alcohols. 10 Their cryoscopic molecular
weights vary from 370 to 680, and the so-called "rubber pitches"
show the highest molecular weights and contain up to 80 per cent
saponifiable matter.

The presence of hydrocarbon decomposition products is evi-
denced largely by the color of the pitch when examined in a thin
layer. If these are present, the pitch will be a black, otherwise it
will have a rich brown color. The percentage of saponifiable con-
stituents present in the fatty-acid pitch is a criterion of its quality.
The larger the percentage, the better will be the quality from the
standpoint of weather-resistance. Fatty-acid pitches of the opti-
mum quality contain not less than 90 per cent of saponifiable con-
stituents. They are as weather resistant as any bituminous sub-
3tance. The smaller the percentage of saponifiable constituents in
the pitch, the less weather-resistant it will prove to be.

In recent years there has been a tendency to remove more and

XIX FATTY-ACID PITCH 401

more of the saponifiable ingredients from the fatty-acid pitches, in
view of the high price commanded by the fatty acids, and also be-
cause of improvements effected in the distillation process. The
author has examined fatty-acid pitches containing as high as 98
per cent unsaponifiable constituents. These appear glossy black in
color and almost opaque in a thin layer, and therefore find a ready
use in the manufacture of cheap lacquers and japans, not intended
for exposure out of doors.

All fatty-acid pitches are converted in a more or less infusible
and insoluble mass upon exposure to the weather for a long period,
or upon heating a short time to a temperature of 250 to 350 C. in
contact with air. 11 This is equally true whether or not unsaponifi-
able constituents are present, and makes this class of pitches espe-
cially valuable for manufacturing, baking japans and varnishes. 12
They may also be hardened, or converted into insoluble and infusible
substances by heating with sulfur, 13 or with sulfur and an alkaline
"accelerator" (e. g., thiocarbanilide or diphenylguanidine ) , 14 or by
heating a mixture of fatty-acid pitch and phenol or cresol with
sulfur dichloride or selenium monochloride, 15 or by heating a mix-
ture of fatty-acid pitch and phenol or cresol with formaldehyde or
hexamethylenetetramine which results in the formation of a hard
resinous condensation product. 16

Various methods have been proposed for blowing fatty-acid
pitches, including: blowing wool-fat pitch with air at an elevated
temperature; 17 blowing a mixture of fatty-acid pitch and montan
wax, with or without the addition of colored mineral pigments; 18
etc. Blowing with air at elevated temperatures rapidly increases
their fusing-point and at the same time tends to convert them into
the insoluble modification. 10

The insoluble (polymerized) form of fatty-acid pitch may again
be rendered soluble in organic solvents by a process of mechanical
mixing (i. e., "hot-rolling") with natural resins, resin esters, or syn-
thetic resins. 20

A highly elastic form, termed "rubber pitch/' is obtained by
heating soft fatty-acid pitch to 240-250 C., with 10 per cent of
either sulfuric or nitric acid, 21 and the resultant product is charac-
terized by being extremely resistant to temperature changes, ap-
proaching vulcanized rubber in its physical properties. Soft pitches

402 FATTY- ACID PITCH, BONE TAR AND BONE-TAR PITCH XIX

may also be hardened by heating with oxides of magnesium, man-
ganese or lead ; lime, 22 picric acid, 28 etc.

Fatty-acid pitches containing a large proportion of saponifiable
constituents show an extremely low susceptibility index, in fact lower
than any other class of bituminous materials. Conversely fatty-
acid pitches in which the unsaponifiable constituents predominate
are apt to have quite a high susceptibility index.

In general, the various classes of fatty-acid pitch are character-
ized by the following predominating physical properties, assuming
that they have been carefully prepared and neither overheated nor
distilled too far, viz. :

Fatty-acid pitches made from lard are usually very ductile with a

low susceptibility index.
Fatty-acid pitches made from tallow are generally hard, lacking in

auctility with a low susceptibility index.
Palm oil pitches are hard, lacking in ductility with a moderately

high susceptibility index.
Cotton-seed-foots pitch is usually soft, of moderate ductility having

a low susceptibility index.
Corn-oil-foots pitch is extremely rubbery, shows little ductility and

has an extremely low susceptibility index.

Packing-house pitch is ductile and has a low susceptibility index.
Bone-fat pitch lacks ductility and has a moderately high suscepti-
bility index. Its color in a thin layer and streak are black.
Garbage and sewage pitches are ductile with a high susceptibility

index. Their color in a thin layer and streak are usually black.
Wool-grease pitch is ductile and has an extremely high susceptibility

index. Its color in a thin layer and streak are usually black.

Fatty-acid pitches (referring to all types) comply with the fol-
lowing characteristics :

(Test i) Color in mass Dark brown to black

(Test la) Homogeneity to the eye at 77 F. , Uniform to gritty

(Test a) Homogeneity under miscroscope Uniform to lumpy

(Test 3) Appearance surface aged indoors one week. Bright

(Test 4) Fracture None to conchoidal

(Test 5) Lustre Bright

(Test 6) Streak on porcelain Light yellow, brown to black

(Test 7) Specific gravity at 77 F 0.90-1 . 10

(Test 9*) Penetration at 77 F , 8 to above 360

(Test 9*) Consistency at 77 F 0-40

(Test 9</) Susceptibility index, f 8-40

(Test 10) Ductility Variable

XIX FATTT-ACID PITCH 403

(Test 154) Fusing-pojnt (K* and S. method) 35-225 F.

(Test 15^) Fusing-point (R. and B. method) 50-245 F.

(Test 16) Volatile matter 500 F., 5 hours o. 5-7. 5 per cent (Set Note)

(Test 17*) Flash-point 450-650 F.

(Test 19) Fixed carbon 5- 35 per cent

(Test 21) Solubility in carbon disulfide 95-100 per cent

Non-mineral matter insoluble o- 5 per cent

Mineral matter o- 5 per cent

(Test 22) Carbenes o- 5 per cent

(Test 23) Solubility in 88 petroleum naphtha 80-100 per cent

(Test 28) Sulfur o per cent

(Test 30) Oxygen 2- 10 per cent

(Test 33) Solid paraffins Trace

(Test 340) Saturated hydrocarbons o- 5 per cent

(Test 34^) Sulfonation residue o- 5 per cent

(Test 370) Acid value (including lactone value) 2-100

(Test 37<r) Ester value , , 40-125

(Test 37 d) Saponification value 60-200

(Test 37?) Saponifiable constituents 5~ 98 per cent

Unsaponifiable constituents 2-95 per cent

(Test 37/) Hydrocarbons in unsapomfiable matter. . . 90-100 per cent

Higher alcohols (cholesterol) in unsaponi-

fiable matter o-io per cent

(Test 37^) Glycerol Tr.-2. 5 per cent

(Test 39) Diazo reaction No

(Test 40) Anthraquinone reaction No

(Test 41) Liebermann-Storch reaction Yes in the case of the wool

grease pitches only

NOTB. In nearly all cases, a skin will form over the surface of the pitch during the determination of the volatile
matter. This is characteristic. Certain fatty-acid pitches, especially those containing a large percentage of
saponifiable constituents, often toughen up and solidify to a rubber-like mass during this test,

Table XXVIII contains the results of the examination of repre-
sentative samples of fatty-acid pitch by the author.

According to Julius Marcusson 24 the saponification value of
fatty-acid pitches ranges from 24 to 106, whereas the saponification
value of petroleum asphalts does not exceed 21. Lukens 2C reports
that the saponification value of fatty-acid pitches ranges from 45 to
100 and of petroleum asphalts from 5 to 18.

Fatty-acid pitches may be distinguished from asphalts by the
small percentages of sulfonation residue and sulfur. Marcusson
contends that fatty-acid pitches contain a trace of sulfur compounds,
derived from impurities present in the original fats and also from
the sulfuric acid used for hydrolysis. Such sulfur compounds are
distinguished from those occurring in asphalts by the fact that they
-are not precipitated by mercuric bromide (Test 28). It is also
interesting to note in this connection that no such precipitate is ob-
tained from fatty-acid pitches that have been vulcanized with sulfur.

404

FATTY-ACID PITCH

XIX

TABLE XXVIII. CHARACTERISTICS

No.

Test

From Lard

From
Tallow

From
Packing-
house
Refuse

2fl

ab
3
4
5
6
7

Physical Characteristics:
Homogeneity to eye at 77 F.

Homo.
Homo.
Bright

Homo.
Lumpy
Bright

Homo.
Homo.
Bright

Homo.
Homo.
Bright
Conch.
Bright
Brown
i 060

Homo.
Homo.
Bright ,

Homogeneity under microscope.

Appearance surface aged seven days
Fracture .

Streak

Yellow
0.972

Yellow
0.980

Yellow
0.990

Brown

1,000

Brown
1.003

Specific gravity at 77 F

9*
9<?

9<*
xofr

Mechanical Tests;
Penetration at 115 F

Soft
Soft
88
o.o
0.7

8.2

18.3

0.0

o.o
o 75

Soft
Soft
85

1.3

9-8
16.7

36
88
o.o
0.05
o 9S

Soft
280
83
o.o
2.4

10.

14.3

25.5
27

0.0

0.05
i 75

22O

1.5

5 8

IS 2
12. S

2-5

28 S
18
o 05

O.2O

2 35

16
ii. 3

23 2
52.0
22 3

18 5
4
o
1-75
3 10
6 2

Soft

IOO

68
0.6
6 3
15-7
15-6
23
81 5 *
20
o.o
o 40

3.25

Penetration at 77 F

Penetration at 32 T

Consistency at 115 F .

Consistency at 77 F

Consistency at 32 F

Ductility in cms. at 115 F

Ductility in cms. at 77 F

Ductility in cms. at 32 F

Tensile strength in kg. at 115 F

Tensile strength in kg. at 77 F

Tensile strength in kg. at 32 F

150
IS*

i?a
19

Thermal Tests:
Fusing-point, deg. F. (K. and S. method)
Fusing-point, deg.F. (R. and B. method)
Volatile 500 F. in 5 hours, per cent. . . .

44- S
57

2.6

Little
Change
452

6.2

59
74
3 o
Little
Change
525

II. 2

70
85
5-3

Gelat.

485.5
10 4

110
130

5-0
Little
Change
486

12.0

182
202

1.2

Little
Change
482

18.4

97
115
1.7
Little
Change
Sio

12.6

Flash-point deg. F

Fixed carbon per cent

21
22

Solubility Tests:
Soluble in carbon disulfide

IOO.O

o.o

0.4

0.0
IOO O

IOO.O
0.0

1-4

0.0
IOO.O

99-7
0.3
1.5
o.o

IOO.O

IOO.O
O.O

0.5
0.0

98.0

98.5

2.1
1.3
O.I

86.7

IOO.O

o.o

2.O

o o

IOO.O

Non-mineral matter insoluble. ..........

Carbenes

Soluble in 88 petroleum naphtha

33
34*
37*
37*
37*
37<*
S7
37/
37/
37*

Chemical Tests
Sulfur

o.o

Solid paraffins * ...

0.0

o.o
17.6

63. 2 \

86. 4 /
167.2
0.5

o.o
0.3
65.0

79-8

144-8
5-5
95-0
5-0

o.o

0.0

63.3

75.9
139.2

1.5

o.o

3.7
23.5

74.1

97-6
5-0

Sulf onation residue *

Acid value . ,

81.95
97.55
179.5

I.O

44.1

112.

I56.I
15.2

97.0
3.0
o.o

Lactone value

Ester value '. * ...

Saponification value. *

Unsaponifiable matter ,..,...

Hydrocarbons In unsaponifiable matter. .
Higher alcohols in unsaponifiable matter.

XIX FATTY-ACID PITCH

OF TYPICAL FATTY-ACID PITCHES

405

From

From
Bone-fat

From
Garbage

From
Sewage

From
Cottonseed-oil
Foots

Corn-
Oil
Foots

From
Palm-oil

From
Wool-
grease

Homo.

*
Homo.

Gritty

Homo.

Gritty

Homo.

Gritty

Lumpy

Homo.

Lumpy

Homo.

Gritty

Lumpy

Bright

Dull

Bright

Conch.

Conch,

SI. dull

Bright

Black

Yellow

Brown

Black

1.036

i 063

i. or i

0.992

0-955

o 998

1.042

1.087

1.020

ISO

145

130

Soft

260

Soft

200

120

150

2.4

2.6

2.9

o.o

i.i

7 2

9 3

11. 7

o.o

7-9

II.7

30.0

2.7

5-1

15.8

24.7

35-2

4.2

55-4

60. 1

48.3

14.1

I6. 5

25.1

56.5

82 o

32,8

41.9

40 5

33-9

19.7

15-3

8.5

29-5

41.0

35.8

72-5

8.5

35-5

26,5

0.5

47-5

o.S

28.5

0.5

0.05

0.50

0.25

o o

o 05

0.75

I.OO

2.20

o.o

o 30

1.25

I 10

O.IO

o.S

1-55

2.2

5.00

0.25

4 ?o

6 2

8.0

a 30

4.2

5-4

9-5

11.25

1.05

126.5

142

134

71.5

JOI

210

161.5

172

91.5

144

162

I5I.5

120

235 5

186

193

1 08 5

o 5

0.6

0.55

4.2

0.38

0.25

3-5

1.2

7.2

Little
Change

Gelat.

Much
Change

Little
Change

575

590

540

635

525

580

462

504

4 6o

19-4

33-5

18.3

10.8

9-2

8.2

26.2

34-0

30.6

97-7

98.2

99-8

97.5

97.3

98.2

96.2

98.8

o.o

0.7

1.7

O. 2

0.4

2.O

0.8

3.8

0.5

0.3

0.35

0.8

1.4

0.3

0-5

1.2

1.3

i.i

O.I

0.4

i.i

0.0

o.o

O.2

2.1

4-3

o.o

94-6

88 3

95-2

IOO.O

92.1

96.4

92.O

82.2

99-0

o o

o.o

O O

0.0

O.I

a o

o.o
o.o

o.o

O.O
O.S

0.2
1.2

0.3

0.0

60 5

46.5

*3-4

36.5

39*5

103.5

95.4

92.9

53.9

88.7

59-7

106.0

120.4

155.9

151.0

172.0

139-4

67.3

125.2

98,0

97.o

7.0

2,0

4.6

2-7

6.0

75-0

60.6

O2 fi

GT *i

QO <

Qsj o

96.0

90.0

93 .0

fi A

yi . y
8 *

S-o

4.0

10,0

O.4

0.55

0,8

2-35

406 FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH XIX

Only cyclic bodies containing sulfur in ring formation give precipi-
tates with mercury.

E. Donath and B. M, Margosches 2 * state that wool-grease
pitch may be identified by boiling 10 g. of the material with 50 cc.
N 2 alcoholic potash under a reflux condenser for ^ hour, and
then filtering the hot liquid. A precipitate will form in the filtrate
on cooling, consisting of the potassium salts of hydroxy fatty acids,
which upon recrystallizing from boiling 95 per cent alcohol and
transposing with hydrochloric acid, will form a white crystalline
mass of the hydroxy fatty acids melting at 80-82 C., which is in-
soluble in water and soluble in hot naphtha. It is claimed that by
this method 25 per cent of wool-grease pitch may be detected in
admixture with other pitches. A further means of identification
depends upon the fact that wool-fat pitches give the cholesterol
reaction.

The author has found the lineal coefficient of expansion of fatty-
acid pitches for i F. (length = i) to average 0.00023.

Fatty-acid pitches flux satisfactorily with mineral waxes, native
and pyrogenous asphalts, tars and pitches. They also flux satisfac-
torily with gilsonite and glance pitch, but not with grahamite*

The following figures indicate that the hardening (toughening)
of fatty-acid pitches on exposure to the weather is due to oxidation.
A sample of soft fatty-acid pitch (the first in Table XXVIII) was
melted and poured into a shallow glass dish, forming a layer
exactly I millimeter thick. This was exposed out of doors for one
year in a dust-free receptacle, protected from the direct action of
the weather, and the following increases in weight noted :

After i month gained 0.62 per cent After 7 months gained 4.20 per cent

2 months 2 . 52 per cent 8 4 . 27 per cent

3 3.27 per cent 9 4.30 per cent

4 3. 50 per cent 10 4.38 per cent

5 3. 86 per cent n 4.42 per cent

6 4.12 per cent 12 4.46 per cent

The original pitch was soft and semi-liquid, but after exposure
for one year it hardened to a tough, leathery mass. The original
fusing-point was 44^ F. (K. and S. method), and at the end of
the year it was 185 F.

XIX BONE TAR AND BONE-TAR PITCH 407

BONE TAR AND BONE-TAR PITCH

In the production of bone tar and bone-tar pitch the crude bones
are first steeped in a i per cent solution of brine for three to four
days, to separate the fibrous matter. They are then degreased by
one of the following methods :

(1) Boiling the bones with water in open vessels;

(2) Boiling with water in closed tanks under a pressure of
10 ib.;

(3) Extracting the bones with a solvent (usually a petroleum
distillate boiling at 100 C.) and removing the last traces of solvent
from the bones by blowing in live steam. The degreased bones are
then treated to extract the glue by again subjecting the bones to the
action of live steam for a lengthy period under a pressure of I C to
20 Ib. in an upright cylindrical boiler with a false bottom. The
glue gradually leaches from the bones, the quantity extracted de-
pending upon the duration of the treatment. When it is desired
to convert the bones into "bone charcoal" (used for the purification
of petroleum distillates and paraffin wax), only one-half of the
gelatinous matter is extracted from the degreased bones, whereupon
the water is drained off and the bones allowed to air-dry. They
are then distilled destructively in horizontal cast-iron retorts, the
distillate being condensed, and the permanent gases consumed under
the retort. The distillate consists of an alkaline aqueous liquor
containing ammoniacal bodies, and 1.5-2.0 per cent (based on the
weight of raw material used) of a tarry layer known as "bone tar,"
"bone oil," "Dippel oil," or "Oleum animale foetidum." The resi-
due remaining in the retort, known as "bone charcoal" or "animal
charcoal," is removed while still hot, and transferred to an air-tight
vessel in which it is allowed to cool. It is then passed through
grinding mills and sieved. The bone charcoal is composed of ap-
proximately 10 per cent of carbon, 75 per cent of calcium phos-
phate, the balance consisting of various other mineral ingredients
and moisture.

The following yields are obtained :

Non-condensable gases 10-15 per cent

Aqueous liquor 10-15 per cent

Bone tar 25-10 per cent

Bone charcoal 55~6o per cent

Total loo-ioo per cent

The bone tar floating on the surface of the aqueous liquor is
drawn off. It consists of fatty substances derived from the fat

408 FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH XIX

which escaped extraction from the bones, also derivatives of pyri-
dine possessing a most disagreeable and penetrating odor, and inci-
dentally serving to distinguish it from all other tars. The charac-
teristics of bone tar are included in Table LXXXIV.

The aqueous liquor is distilled, and the distillate caught in sul-
furic acid to recover the ammonium compounds as ammonium sul-
fate. The residue is used as a fertilizer.

The bone tar is subjected to fractional distillation to recover the
bone-tar pitch, the properties of which are also embodied in
Table LXXXIV.

Bone-tar pitch is intermediate in its physical properties between
asphalts and the fatty-acid pitches. On destructive distillation, it
yields an aqueous distillate which reacts distinctly alkaline. It is
moderately susceptible to temperature changes, and on a par with
higher grades of residual asphalts and inferior grades of fatty-acid
pitches in its weather-resisting properties. It is the blackest of all
pitches and is therefore valued by the varnish maker to deepen the
color of japans. It is soluble in pyridine bases and only partly
soluble in benzol and petroleum distillates, but upon fluxing with
rosin and vegetable oils it becomes soluble. Since it is produced in
comparatively small quantities, it can scarcely be regarded as a
commercial product

GLYCERIN PITCH

This pitch is obtained upon the purification of glycerin by dis-
tillation with superheated steam. It is greenish brown to black in
color and contains a certain amount of water-soluble constituents.
It is produced in limited quantities and has a restricted use. 27

Glycerin pitch contains polyglycerins, metallic soaps, metallic
salts, etc. It is used as a lubricant in boring, for making printing
inks, as a core binder, 28 etc. Upon heating with phthalic anhydride
and succinic, malic, fumaric, citric, or malomalic acid, a water-
resistant synthetic resin is obtained. 29

PART IF
PYROGENOUS ASPHALTS AND WAXES

CHAPTER XX
PETROLEUM ASPHALTS

"Petroleum asphalts" are obtained from petroleums by distilla-
tion, blowing with air at elevated temperatures, and in the refining
of certain distillates with sulfuric acid. These methods will be
described in greater detail later.

Varieties of Petroleum. Petroleum as it occurs in different
parts of the world, varies widely in composition. Certain varieties
are composed of open chain hydrocarbons, others are made up
exclusively of cyclic hydrocarbons, and still others occur showing
every possible gradation between these two extremes. Numerous
classifications have been proposed, based on its chemical composi-
tion in general, or the presence of a substantial proportion of char-
acteristic bodies, such as the paraffin series of hydrocarbons, the
naphthene series, sulfur derivatives, nitrogenous bodies, benzols,
terpenes, etc. 1

From the standpoint of the asphalt content, petroleums may be
divided into three groups, viz. :

(1) Asphaltic petroleums. These carry a substantial amount
of asphaltic bodies, with solid paraffins either absent or present only
in traces.

(2) Semi-asphaltic petroleums. These carry a moderate
amount of asphaltic bodies, but in any event generate or produce
asphalt-like bodies during the distillation process. Solid paraffins
may or may not be present

(3) Non-asphaltic petroleums. These do not carry asphaltic
bodies but may generate them during the distillation process. Solid
paraffins are usually present, but not necessarily so.

409

410

PETROLEUM ASPHALTS

DEHYDRATION OF PETROLEUM

411

Table XXIX contains a list of the most important occurrences
of petroleum throughout the world, classified according to the as-
phalt content and solid paraffins present.

Different crudes yield varying amounts of asphalt on steam or
vacuum distillation, dependent upon the character of the oil and the
amount of asphalt content The following figures are illustrative,
and indicate in a general way the yield of asphalt by weight, having
a fusing-point of 100 F. (R. and B. method) :

Type of Crude Oil

A. P. I. Gravity

Yield of Asphalt

Mid-continental (Oklahoma)

2 per cent

Seminole

ik oer cent

Peruvian

4 per cent

Mid-continental (Illinois)

5J per cent

Light Californian

12 per cent

Texan.

14 per cent

Heavy Californian.

65 per cent

Mexican (Panuco)

65 per cent

DEHYDRATION OF PETROLEUM

Nearly all crude petroleums carry more or less water, some
being entrained mechanically, and in other cases held in a state of
emulsion. Ordinarily the oil is permitted to stand long enough by
itself for the water and sand to separate. Crude oils containing
less than 2 per cent of water are accepted by the pipe lines and re-
fineries. If they contain more than 2 per cent, they must first be
dehydrated. Certain heavy asphaltic and waxy crudes carry as
much as 70 to 90 per cent of water held in suspension by brine and
colloidal mineral matter (e. g., hydrated aluminium silicates). The
following methods may be used to remove the water, where it is
necessary to deliver the oil to the pipe line or refinery within the
prescribed limitations :

1 i ) Settling. Heating and subsidence will break up emulsions
in many cases. This may be facilitated by adding chemicals, as for
example i per cent of a mixture of sodium oleate, sodium resinate
and sodium silicate ; or else sulf onated pleic acid. 2

(2) Centrifugtng. This consists in centrifuging the oil at a
temperature of no to 180 F. in a centrifuge operating at 17,000
r.p.m. by means of a turbine. 3

412 PETROLEUM ASPHALTS XX

(3) Tube Stills. The most satisfactory manner to break up
emulsions consists in running the oil through a tube- or pipe-still
under pressure and heated to 300 F., whereupon it is released in
a vaporizer at atmospheric pressure. The water and oil vapors
are recondensed, but will not again emulsify on account of the ab-
sence of emulsifying agents and the low viscosity of the oil.

DISTILLATION OF PETROLEUM

Petroleum is separated into various commercial products by
means of distillation, of which the following methods are in vogue :

(i) Batch Stills. These are still in use in the older refineries,
but are rapidly being superseded by tube stills. The efficiency in
transmission of heat to the oil in the batch still is very poor, being
rarely better than 30 per cent, equivalent to a consumption of 6
bbl. of fuel oil for each 100 bbl. of distillate. Approximately 0.85
bbl. distillate is produced per day, per sq. ft. of surface fired, or
expressed differently, 2.5 gal. distillate will vaporize per hour, per
sq. ft. vaporizing surface. Fig. 121 illustrates a typical batch-still
installation. The still proper holds 1000 to 1500 bbl. of 42 gal",
each. The distillation process may be carried on either with, 4 or
without the use of steam. Where steam is employed, the process
is known as "steam distillation," otherwise it is termed "dry dis-
tillation."

Steam Distillation. This is also known as the "fractional" dis-
tillation process and consists in introducing dry steam, termed "bot-
tom steam" into the still, which assists in the vaporization of the
volatile constituents and minimizes decomposition of the distillate
and residue. Its action is based on the physical law that the boiling-
point of a pair of non-miscible or slightly miscible liquids is lower
than that of either pure component. The introduction of steam,
therefore, serves materially to lower the boiling-point of the petro-
leum, and produces the maximum yield of heavy lubricating oils.
It also tends to economize in fuel, and to shorten the distillation
process. The steam upon being dried by passing through a trap is
introduced through perforated pipes at the bottom of the still when
the temperature of the contents exceeds the boiling-point of water.

In treating ^asphaltic petroleums by the steam-distillation proc-
ess in batch stills, the charge is distilled until the residue attains
the proper consistency, which is controlled by sampling the residue
through petcocks set in the still, or by recording the temperature of
the residue, or by observing the character of the distillate. The
further the process is continued, the higher will be the fusing-point
and the harder the consistency of the residue. The temperature of
the residue at the termination of the process will vary between 600

DISTILLATION OF PETROLEUM

413

and 750 F., and the time of distillation between twelve and thirty-
six hours. When the distillation is completed, the residuum is run
or blown into a closed cylindrical vessel constructed of steel, where

it is allowed to cool until the temperature is reduced sufficiently to
permit its being filled into barrels or drums without danger of ig-
niting on coming in contact with air.

414 PETROLEUM ASPHALTS XX

Where the residue is distilled to a definite consistency without
further treatment, the distillation is known as Straight running,
and the residue a "straight run asphalt." In certain cases a portion
or "fraction" of the distillate is mixed with the residue at the close
of the distillation, which is termed "cutting back," 5 the object of
which is to modify the properties of the residual product or to
dispose economically of a fraction which otherwise has little value
commercially.

Cut-back residual oil is composed of residual oil, cut back with
a petroleum distillate, which should be of a character which will
volatilize within a reasonably short time after application to a sur-
face. Relatively volatile distillates are generally used in the manu-
facture of cut-back asphalts. The larger the quantity of distillate
added, the more fluid will be the cut-back product. 6

In treating semi-asphaltic and non-asphaltic petroleums by the
steam-distillation process in batch stills, steam is introduced when
all the naphtha has distilled off, and the distillation continued until
the lubricating oils have distilled over, whereupon the temperature
reaches 620 F. At this point the distillation is stopped. In the
case of non-asphaltic crude oil, the so-called "cylinder stock" re-
mains in the still, and with semi-asphaltic crude, an asphaltic residue
remains behind, which may either be marketed as such, or treated
with air to produce a "blown asphalt."

Table XXX gives an outline of the steam-distillation process as
applied to asphaltic petroleum, and Table XXXI as applied to
semi-asphaltic and non-asphaltic petroleums. ^

Dry Distillation. This is sometimes termed the straight or
"destructive" or "cracking" distillation, by means of which a certain
proportion of the higher boiling-point constituents decompose or
break down, forming correspondingly larger yields of the low boil-
ing-point constituents. The dry distillation process is accordingly
used when the distiller wishes to produce a maximum amount of
gasoline and illuminating oil, or in cases where the crude is unfit
for manufacturing lubricating oil.

Upon treating semi-asphaltic and non-asphaltic petroleums by
the dry-distillation process in batch stills, a large amount of crack-
ing taices place when the crude kerosene fraction distils over and
the temperature of the still reaches 625 F. The fires are accord-
ingly moderated to slow down the distillation and accelerate the
decomposition as much as possible. The "cracked" distillate is
fractioned until the temperature in the still reaches 675 to 700 F.,
whereupon the distillation is brought to a close. There remains a
viscous dark-colored "residuum" varying in gravity from 20 to 25
Baume which may either be marketed under the name of "residual
oil" or "flux oil" or else distilled separately in another still, known

DISTILLATION OF PETROLEUM

415

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416

PETROLEUM ASPHALTS

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XX DISTILLATION OF PETROLEUM 417

as a "tar still," to obtain the wax or paraffin distillate, wax-tailings
and coke bottoms. The operation is carried on as rapidly as pos-
sible to avoid unnecessary cracking, and render the paraffin crystal-
line* The paraffin distillate comes over first, followed by the wax-
tailings, until nothing but the coke remains in the still, which after
cooling is removed with a pick and shovel. The method of pro-
cedure is illustrated in Table XXXII.

(2) Continuous Stills. Stills of this type are now encountered
infrequently. They are constructed similar to batch stills, the oil
flowing from one still to another, and each producing a predeter-
mined grade of distillate. The whole circumference of a continuous
still may be fired and approximately 1.42 bbl. of distillate will be
obtained per day, per square foot of firing surface, similarly 2.5 gal.
of distillate will evaporate per square foot of vaporizing surface.
The efficiency of continuous stills is approximately 40 per cent,
equivalent to a consumption of 5 bbl. of fuel oil per 100 bbl. dis-
tillate produced.

(3) Tube or Pipe Stills. Tube or pipe stills, aiso termed 'Vac-
uum flash coils" when connected with vacuum fractioning (or
"flash") chambers 7 are rapidly replacing the other types of stills
on account of their lower initial cost, greater through-put, and econ-
omy in operation. The oil is pumped under pressure through a
series of interconnecting tubes heated in a furnace. Such stills are
built in units capable of handling up to 15,000 bbl. of crude oil per
day. It is possible to heat the oil as high as 900 to 950 F. because
of the high rate of heat transfer through the tubes and the4iigh
velocity of the oil. This heat transfer may run as high as 200
B.t.u. per sq. ft., per hour, per degree F. difference in temperature.
Their efficiency will range from 65 to 80 per cent, equivalent to a
consumption of less than 3 bbl. fuel oil per 100 bbl. distillate
produced.

By means of a tube still, as much as 90 per cent of the crude
may be recovered as distillate and it is not infrequent that 10 per
cent more gasoline will be obtained than is present in the crude oil
under treatment, due to the cracking which takes place. Where
more than 80 per cent of the crude is converted into distillate, there
results a small amount of gas, which tends to lower the distillation
temperature. The tube still has the advantage over the batch still
in that the temperature may be controlled more accurately, due to
the smaller volume of oil in the still, localized overheating is pre-
vented, and the fractioning takes place within much sharper limits.
Moreover, the cost of operation is from Vio to %5 that of batch
stills, and in addition remove the possibility of recondensation and
run back of the distillate. Whereas the asphaltic residue may re-
main at extreme temperatures for 12 to 24 hours in a cylindrical

418 PETROLEUM ASPHALTS XX

batch still, the residue is subjected to the maximum temperature for
only a fraction of a minute in a tube still, thereby minimizing any
tendency towards carbonization.

Tube stills are now used successfully for all types of distillation,
including the topping or skimming of crudes, the manufacture of
lubricating stock, the cracking of gas oils and other distillates, and
even for running the oil to coke, provided a speed of flow is attained
in the tubes that the coke will not separate except in the vaporizer.
They are accordingly designed to accomplish the following : dehy-
drate the oil and remove one or more fractions in the following
order, viz.: gasoline, kerosene, gas oil and/or wax-distillate (in the
case of semi-asphaltic and non-asphaltic petroleums). The residue
consists either of fuel oil or residual oil, depending upon the extent
to which the distillation has been carried.

The construction details of a tube-heater is shown in Fig. 122.

The successful operation of the tube still is closely connected
with the improved fractioning equipment developed during the past
five to ten years. It is now possible to produce fractions of the
proper distillation range in one operation. The so-called bubble-
cap tray-tower has given phenomenal results. It consists in an ar-
rangement for the repeated absorption and redistillation of the
distillate, thus separating the heavier hydrocarbons, which are car-
ried over by the associated lighter hydrocarbons. Such a tower is
illustrated in Fig. 123. The tower is insulated to keep it at an
unvarying temperature and means are provided to keep a definite
relation between the up-flowing vapors and the down-coming liquid
which flows from tray to tray in the tower. It has been found that
very volatile distillates can only be fractioned at high pressures-
usually 250 Ib. per sq. in.; and moreover difficultly volatile distil-
lates can be fractioned most closely in towers operating under a
vacuum of 29, or in some cases above 29^4 i n - 8

The general arrangement of a two-stage combination atmos-
pheric and vacuum distillation unit for treating 10,000 barrels of
crude in 24 hours is illustrated in Fig. 124.* This procedure in-
volves the recovery of the lighter distillates, including naphtha,
kerosene and a portion of the gas oil by distillation at atmospheric
pressure, and thereupon transferring the residue to a vacuum dis-
tillation unit in which the balance of the gas oil and several lubri-
cating-stock fractions are recovered as distillates and asphalt as a
final residuum.

The general operation of this unit is as follows : crude is taken
from storage and pumped through the atmospheric vapor heat ex-

JtX

DISTILLATION OF PETROLEUM

419

changer and thence to a settling tank for removal of solids and
water. The crude then flows through the vacuum-stage exchangers,
acquiring a final preheat temperature of approximately 350 F.

The preheated crude is transferred to the atmospheric stage tube
still and heated to a temperature sufficient to effect the desired
vaporization in the atmospheric f ractioning tower.

120

PETROLEUM ASPHALTS

'SkctionThno'

Dephlecmating

Tower

Section A. A

!6"Manhole

***

& Boiler
Flange"

I 1 1 ii . - v

3 "Recharging "Stock
fo Cond Box

Courtesy Kansas City Testing Laboratory.
FIG. 123. Bubble-cap Tray-tower for Fractioning Petroleum.

DISTILLATION OF PETROLEUM

421

422 PETROLEUM ASPHALTS XX

In the atmospheric tower four distillate streams are recovered :
gasoline as the top vapor stream, and naphtha, kerosene, and gas
oil as liquid side streams.

The side streams are removed from respective plates in the
main tower to external stripping sections for steam stripping to
remove the lighter ends. The stripping steam and vapors are re-
turned to the main tower at points above the respective stream
take-offs.

The atmospheric stage bottoms are subjected to steam stripping
on plates below the tower inlet The reduced crude is pumped hot
from the base of the atmospheric tower directly to the vacuum-stage
tube still for further heating.

The vacuum tube still discharges into the vacuum fractionating
tower, which is maintained at a low absolute pressure. Three distil-
late streams are recovered from the vacuum stage : heavy gas oil as
the top vapor stream and paraffin distillate and cylinder stock as
liquid side streams. Asphalt bottoms are recovered as a residue
from the base of the tower. Steam is introduced into the base of
the tower for stripping the asphalt and for partial-pressure effect.

Vacuum is maintained on the system by a barometric condenser
backed by steam jet ejectors. The overhead vapor stream, consist-
ing of gas oil and process steam, passes through vapor heat ex-
changers and water-cooled surface condensers. Because of the
temperature and pressure conditions maintained at the condenser
outlet, the process steam remains in the vapor state and flows to
the barometric condenser, while practically complete condensation
of the gas oil is obtained. The desirability of obtaining sharp
phase separation at the vacuum condenser outlet with a low partial
pressure of gas oil vapor in the uncondensed steam, dictates the
quantity of gas oil to be removed in the atmospheric stage ; i.e., the
initial boiling point of the vacuum-stage gas oil must be sufficiently
high to insure substantially complete condensation.

Process conditions and sizes of the major items of equipment
for this installation are shown in Table XXXIII.

Two-stage crude distillation units with individual unit capacities
up to 50,000 barrels per day are now under construction. Based on
330 stream days per year, 50,000 barrels per day correspond to
16,500,000 barrels of crude oil per year. These figures indicate

XX DISTILLATION OF PETROLEUM 423

the enormous capacity which can be built into single process units
of this type.

The two-stage units effect a separation between asphalt and
lubricating stocks by distillation. Because of overlapping in boiling
point range between the heaviest lubricating fraction and the lower
boiling asphaltic material, a sharp separation is difficult. Hence it

TABLE XXXIII
TWO-STAGE DISTILLATION UNIT

Crude charge, bbl./24 hr 10,000

Vacuum-stage charge, bbl./24 hr 5,ooo

Final asphalt residuum, bbL/24 hr 837

Temp., F,:

Atmospheric tower inlet 599

Atmospheric tower top 224

Atmospheric naphtha draw-off 328

Atmospheric kerosene draw-off 420

Atmospheric gas oil draw-off. 537

Atmospheric bottoms draw-off 530

Vacuum tower inlet 772

Vacuum tower top 364

Vacuum tower light lube draw-off (wax dist.) 504

Vacuum tower heavy lube draw-off (cylinder stock) 690

Vacuum tower bottoms draw-off 709

Absolute pressure at top of vacuum tower, mm 60

Atmospheric tower:

Diam., ft II

No. plates (30 above inlet, 4 below) 34

Vacuum tower:

Diam., ft 17

No. plates (16 above inlet, 4 below) 20

Process steam, lb./hr.:

Atmospheric tower and strippers 3>5oo

Vacuum tower 45oo

Vapor velocity:

Atmospheric tower:

Ft./sec 2.21

Lb./sq. ft./hr 1,360

Vacuum tower:

Ft./sec 7.05

Lb./sq. ft./hr 600

has been found advisable in some instances to remove a clean,
heavy, lubricating stock several trays above the flash zone and a
small quantity of material containing the lighter asphaltic materials
as a total draw-off from the tray immediately above the tower in-
let. This stream can be treated separately from the clean bulk
heavy lubricating stock, or if the heavy lubricating available in the
crude exceeds requirements, it can be routed to cracking.

424 PETROLEUM ASPHALTS XX

Several lubricating-stock rerun operations are commonly prac-
ticed. The modern equipment in general use consists of atmos-
pheric or vacuum pipe stills similar in design to those used for crude
units. Major operations are as follows :

Rerunning of Pressed Wax Distillate. This operation consists
in the redistillation of stock which has been dewaxed by filter press-
ing. The rerun operation eliminates non-viscous gas oil, and the
balance of the dewaxed oil is fractioned into two or more neutral
oils for use in blending for automotive lubricant or in the manufac-
ture of light machine oils. Atmospheric distillation is customarily
employed with tube still outlet temperatures of 700 to 730 F.

Cylinder Stock Solution Rerunning. The cylinder stock-naphtha
mixture from centrifuge dewaxing is rerun in atmospheric tube stills
for removal of the naphtha diluent. Tube-still outlet temperatures
of 475 to 550 F. are required.

Rerun of Treated and Dewaxed Long Residuum for Motor
Oil Grades. A vacuum operation is dictated by the fact that lubri-
cating fractions of high boiling point are taken overhead.

CRACKING PROCESSES

These have been developed for the purpose of increasing the
yield of gasoline, which is accomplished by heating the crude oil to a
high temperature under pressure.

(1) Liquid Phase Cracking. This involves heating and crack-
ing at high pressures without permitting distillation to take place
during the reaction stage. The heat is accordingly applied to the
liquid under a sufficiently high pressure to maintain it as a liquid
and prevent the distillation and consequent drop in temperature in
the reaction chamber. These processes usually operate continu-
ously, with separate heating and reaction chambers.

(a) Tube-and-Tank Process. This is illustrated diagrammat-
ically in Fig. 125, and consists of a tube heater A in which the oil
enters under a pressure of 400 Ib. per sq. in. At the exit the pres-
sure is 350 Ib. and the temperature 850 F. The oil then enters an
insulated vertical reaction chamber JS, which is kept filled with liquid
under 350 Ib. pressure, and at its exit the temperature has fallen
to 785 F. Before it enters the bubble tower C, the pressure is re-
duced to 50 Ib. by the release valve D, and its temperature as it
enters the tower is 700 F. The bubble tower separates the gas oil
(i.e., cycle stock) and the pressure tar. The cycle stock is run
through the process again, mixed with a certain proportion of fresh

CRACKING PROCESSES

425

crude oil. The gasoline is then condensed and separated from the
fixed gas which is consumed as part fuel in the tube heater.

(b) Cross Process. This is illustrated in Fig. 126 and consists
of two tube heaters A and B using common vaporizing and frac-
tioning towers D and E. The first heater operates on crude oil, or
fuel oil, or in fact any petroleum product and heats the charging
stock to 850 F. under 350 Ib. pressure. The second heater B op-
erates on the recycling stock, which it heats to 900 F. under 600-
700 Ib. pressure. From here the oil is forced into an insulated reac-
tion chamber C, where it is maintained in liquid condition for fifteen
minutes at a temperature of 600-700 F., during which all the
carbon formed in the cracking operation is deposited as coke, which
must be cleaned out from time to time. At the exit of C there is

Crude oil*

FIG. 125. Tube-and-Tank Cracking Process.

a reducing-valve which discharges the product into a vaporizer D
maintained at practically atmospheric pressure.^ As the cracked oil
enters the vaporizer, it blends continuously with the stream from
the tube still A. The fractioning tower E separates the recycling
stock (gas oil), and the gas-separator F separates the gasoline
from the gas. Tube still A acts as a skimming plant which sepa-
rates the gasoline normally present in the crude oil, plus gas-oil,
plus pressure-tar. The final operation results in the production of
gasoline, recycling stock (gas oil), pressure-tar, gas (which is
burned underneath the tube stills), and carbon (which must be peri-
odically removed from the reaction chamber). ^ The pressure-tar
may be marketed as fuel oil, since it is very fluid, and practically
free from carbon (less than */ 2 per cent). A plant of this type will
operate successfully on all types of crude oil, emulsified crudes, as
well as any fraction distilled therefrom.

426

PETROLEUM ASPHALTS

(c) Holmes-Manley Process. This is very similar to the Tube-
and-Tank Process, the only material difference being that four or
more vertical reaction chambers are mounted side by side in a com-
mon gas-fired furnace, and in addition each reaction chamber is pro-
vided with a motor-driven shaft having scrapers to assist in re-
moving the coke. The oil enters the tube heater under 350 Ib.
pressure and leaves at 300 Ib* and 800 F. A reducing-valve is

Crude off*

" Recycling
stock

FIG. 126. Cross Cracking Process.

located between the condenser and the gas-separator in which a
pressure of 80 Ib. is maintained.

(2) Mixed Phase Cracking. This involves pressure distillation
with simultaneous heating, cracking and distillation. The efficiency
is stated to be less than in the liquid phase cracking, because of the
added heat consumed in the repeated vaporization and condensation
of the uncracked distillates.

(a) Burton Process. This is a batch operation and takes place
in stills with refluxing. The modern high-pressure Burton still 10
consists of a pair of heat-insulated cylinders A (Fig. 127), attached
to a tube heater 5, mounted in a furnace below. This is connected
with a bubble-tower C, which separates the gas^ and gasoline from
the heavier distillate which is allowed to recycle into the still Con-
denser D separates the gasoline, which in turn is separated from
the gas in the gas-separator E. The entire system up to the release-
valve F is maintained under a pressure of 925 Ib. The still AB is
heated to 750 F. and the bubble tower C to 550 F. The carbon

CROCKING PROCESSES

427

assumes a granular condition and is cleaned out after each run of
forty-eight hours, whereupon the still is recharged. Upon running
gas-oil there are produced 80 per cent gasoline, 6 per cent gas, 0.4
per cent coke and 13.6 per cent pressure-tar. The pressure-tar

far --

rx, ry O

'>. ' Coke \^s<?as.*^S

FIG. 127. Burton Cracking Process.

carries but a small amount of carbonaceous matter and when sub-
jected to steam-distillation in a batch still produces a hard asphalt
of high ductility, almost completely soluble in carbon disulfide, and

FIG. 128. Dubb's Cracking Process.

which is quite susceptible to temperature changes* 11 This has been
marketed in the United States under the name "Stanolite," which,
according to the experience of the author, is lacking in weather-
resisting properties.

428 PETROLEUM ASPHALTS XX

(b) Dubb's Process. This process operates continuously at a
high temperature. The lay-out is illustrated in Fig, 128 and con-
sists of a tube still A heated partly with the fixed gas produced in
the cracking operation and partly by means of fuel oil, which raises
it to 850900 F. under a pressure of 250 Ib. The product there-
upon enters the reaction chamber B in which it is vaporized, accom-
panied by a drop in temperature and deposition of coke. The va-
pors next pass into a dephlegmator C where they encounter a stream
of the raw charging stock and upon mixing pass downward and
back to the tube still A. The uncondensed vapors pass out at the
top of the dephlegmator and then into a coil-condenser D. The
valve E releases the pressure and the separator F removes the gas
from the gasoline. Where it is desired to produce pressure-tar (in
this case residual oil), it is drawn off the bottom of the reaction
chamber JS, otherwise the valve is kept shut and a slightly higher
temperature is carried on the transfer liquid. The hot residue may
be quenched by running into water and separating. 12 The foregoing
process results in the production of cracked vapor and coke, instead
of cracked vapors, coke and residual oil. The following are re-
ported to have been obtained on one cycle :

From Mid-continental gas oil 44.3 per cent gasoline

From Mid-continental fuel oil 40. 9 per cent gasoline

From Panuco 10 B6. residuum 21 . i per cent gasoline

From Venezuela 13 B6. residuum 26. 9 per cent gasoline

The various cracking processes ranked as follows in the United
States in relation to the respective through-puts: Burton, Cross,
Holmes-Manly, Tube-and-Tank and Dubbs. The following types
of stock may be used in the cracking operations : crude oils of any
type, emulsified crudes of any type, topped crudes, fuel oil, gas oil,
and mixtures of the foregoing with recycling stock. The following
in general represent the products obtained: fixed gases (used as
fuel), gasoline, pressure-tar and in special cases an intermediate
cut known as recycling stock (which is retreated and still further
cracked), also coke. After removal of the soluble oils, the coke
tests as follows: volatile matter 13 per cent, fixed carbon 80 to 86
per cent, ash i to 7 per cent, and sulfur i to 2 per cent

The pressure-tar may be utilized in the following ways, viz.:
marketed as fuel oil (provided it is sufficiently liquid and free from
carbonaceous ^matter ); or it may be marketed as soft asphalt flux
(provided it is more viscous than fuel oil) ; or it may be mixed in
suitable proportions with residual asphalts derived from the regular
distillation process ; n or it may be steam-distilled in a batch still
to produce residual asphalt of various grades; or distilled under
vacuum to the desired grade ; 14 or it may be blown with air to pro-

LIQUID PRODUCTS

429

duce blown asphalts of the desired grade, either alone, 15 or in ad-
mixture with other products, such as an "aromatic extract of a pe-
troleum oil/' le or an untreated residual oil in combination with an
asphalt of naphthene base, 17 or the oily layer separated from
sludge asphalt 18 Pressure-tars may be hydrogenated under pres-
sure at 345400 C. in the presence of a catalyst. 19

Various tars from coal (e. g., low-temperature coal tar, water-
gas tar, coke-oven tar, etc. ) , shale, lignite, peat, or wood, may like-
wise be treated by the cracking process. 20 The following figures
will indicate the yields when such tars are submitted to the crack-
ing process :

Spec. Grav.
(A. P. I.)

Gas

Cu. ft.
per bbl.

Motor
Fuel
Per Cent

Fuel or
Diesel Oil
Per Cent

Coke.
Lbs. per
barrel

Low-temperature coal-tar.
Intermediate temperature
coal-tar

8-9
6.0

570
<oo

28.8
14.5

10.3

17.7

241

High-temperature coal-tar.
Lignite tar

7.0
IT. Q

706

767

12. 1

38.3

22.6

i 5 8

241

Brown-coal tar

Q.2

835

28.6

The following constitute the various products pertaining to, or
derived from petroleum : 21

Liquid Products

Petroleum Naphtha. A generic term applied to refined, partly
refined or unrefined petroleum products and liquid products of nat-
ural gas, not less than 10 per cent of which distils below 347 F.
(175 C.) and not less than 95 per cent of which distils below
464 F. (240 C.), when subjected to distillation in accordance
with the standard method of test (A.S.T.M. Designation: D 86).

NOTE. The "naphthas" used for specific purposes such as cleaning, manufacture of
rubber, manufacture of paints and varnishes, etc., are made to conform to specifications
which may require products of considerably greater volatility than that set by the limits
of this generic definition.

Gasoline. A refined petroleum naphtha which by its composi-
tion is suitable for use as a carburant in internal combustion engines.

Petroleum Spirits (White Spirits). A refined petroleum dis-
tillate with a minimum flash point of 70 F. (21 C.) determined
by the Tag Closed Tester (A.S.T.M. Designation: D 56), or by
the Abel Tester, with the volatility and other properties making

430 PETROLEUM ASPHALTS XX

it suitable as a thinner and solvent in paints, varnishes and similar
products.

NOTE. The term "turpentine substitute" as applied to petroleum spirits is to be con-
demned as false and misleading. The term "mineral spirits" which is frequently used
in the paint and varnish industry is a misnomer as it includes within its scope not only
petroleum products, but other hydrocarbon mixtures, such as coal-tar distillates. In
Great Britain the term "petroleum spirits" is applied to a very light hydrocarbon mixture
having a flash point below 32 F. (o C.).

Engine Distillate. A refined or unrefined petroleum distillate
similar to naphtha, but often of higher distillation range.

Tops. The unrefined distillate obtained in topping a crude pe-
troleum.

Kerosene. A refined petroleum distillate having a flash point
not below 73 F. (23 C.), as determined by the Abel Tester
(which is approximately equivalent to 73 F. (23 C.) as deter-
mined by the Tag Closed Tester; A.S.T.M. Designation: D 56),
and suitable for use as an illuminant when burned in a wick lamp.

E. In the United States of America local ordinances or insurance regulations re-
quire flash points higher than 73 F. (23 C), Tag Closed Tester.

Gas OIL A liquid petroleum distillate having a viscosity inter-
mediate between that of kerosene and lubricating oil.

N OTEt it should be understood that oils, other than gas oil as defined above, may be
and are used in the manufacture of gas.

Fuel OIL Any liquid or liquefiable petroleum product burned
for the generation of heat in a furnace or firebox, or for the gen-
eration of power in an engine, exclusive of oils with a flash point
below 100 F., Tag Closed Tester, and oils burned in cotton or
wool-wick burners. Fuel oils in common use fall into one of four
classes: (i) residual fuel oils, which are topped crude petroleums
or viscous residuums obtained in refinery operations; (2) distillate
fuel oils, which are distillates derived directly or indirectly from
crude petroleum; (3) crude petroleums and weathered crude pe-
troleums of relatively low commercial value; (4) blended fuels,
which are mixtures or two or more of the three preceding classes.

Lubricating Oils. A heavy distillate suitable for use in lubri-
cation.

Semi-Solid to Solid Distillates

(a) Petrolatum. This term is applied to the product obtained
by diluting either crude paraffinaceous petroleum, or the residue
known as u cylinder stock" (obtained when paraffinaceous petroleum
has been steam-distilled to remove the lighter distillates and gas-
oil) with naphtha. The mixture is then chilled or allowed to "cold

XX SEMI-SOLID TO SOLID RESIDUES 431

set" until an amorphous residue settles out, which is separated
either by sedimentation or by centrifuging. The naphtha carried
by the petrolatum is recovered by steam distillation. Petrolatum
is also known under the names vaseline, petroleum grease, petro-
leum jelly, and liquid paraffin.

(b) Paraffin Wax. This is derived from paraffin-bearing pe-
troleums, and is separated from the lubricating oil and paraffin dis-
tillates by crystallization at low temperatures and filter-pressing. It
is classified by its color and melting-point. The terms "paraffin
scale" and "scale wax" are generally applied to the low melting-
point variety, and "refined paraffin wax" to the harder variety. Its
melting-point varies from 100-135 F.

(c) Wax Tailings. This represents the fraction obtained in
the dry distillation of petroleums, and recovered immediately prior
to coking. It is peculiar in its properties and generally free from
paraffin wax.

Semi-Solid to Solid Residues

(0) Residual Oil. This term is applied to the liquid to semi-
solid residues obtained from : ( I ) the destructive distillation of non-
asphaltic petroleum; (2) the distillation of semi-asphaltic and
asphaltic petroleums; (3) the distillation of pressure-tar; (4) the
fluxing of harder residual asphalts with heavy distillates (known as
"cut-back asphalt"). The following terms are used synonymously
with residual oil, viz. : asphaltum oil, liquid asphalt, flux, flux oil,
fluxing oil, roofing flux, road oil, dust-laying oil, black oil and petro-
leum tailings; and abroad as mazout, mazut and masut (Tartar),
ostatki or astatki (Russian), also pacura (Rumanian).

(b) Residual Asphalt. This term is applied to the semi-solid
to solid residues obtained from the distillation of semi-asphaltic and
asphaltic petroleums and pressure-tars. The following terms are
used synonymously with residual asphalt, viz. : petroleum asphalt,
petroleum pitch, petroleum residue, road binder, carpeting medium,
and seal-coating material.

(c) Blown Asphalt. A term used to designate the product ob-
tained by blowing air through residual oil at elevated temperatures.
Also known under the names oxidized asphalt, oxygenized asphalt,
oxygenated asphalt and condensed asphalt.

(d) Sulfurized Asphalt. This term is applied to the product
obtained by heating residual oil* or residual asphalt with sulfur at
high temperatures. Also known under the names Dubbs asphalt,
Pittsburgh flux and Ventura flux.

(e) Sludge Asphalt. This term is applied to the asphaltic
product separated from the acid sludge produced in refining petro-

432 PETROLEUM ASPHALTS XX

leum distillates with sulfuric acid. It is also known under the
names acid-asphalt, acid-sludge asphalt, etc.

RESIDUAL OILS

Residual oils are distinguished from fuel oils by having a
higher specific gravity, a higher fusing-point and generally a smaller
amount of volatile matter and higher flash-point (except in the case
of cut-back residual oils). The two classes of products merge to-
gether, so that there is no sharp line of demarcation between them.

The characteristics of residual oils depend upon three factors,
viz. :

(1) The type and nature of the petroleum from which they
are produced.

( 2 ) The particular form of apparatus in which the distillation
is carried out.

(3) The extent to which the distillation has been conducted,
and whether or not the product has been cut back.

The following will indicate in a general way the effect of these
factors upon the nature of the residual oil.

Fusing-point. All types of residual oil fall within the range of
32 to 1 10 F., R. and B. method (Test 156) ; or 20 to 100 F., K.
and S. method (Test 150).

Specific Gravity. The type of petroleum and the nature of the
distillation process affects the specific gravity at 77 F. (Test 7) as
follows :

When Straight-
distilled

When Distilled
from Pressure-tar

0.95-0.9$

1.00-1.03

From semi-asphaltic petroleum

o . 90-1 . oo

1.02-1.05

From asphaltic petroleum

0.9<-I.O2

1.03-1.07

Solid Paraffins. The percentage of solid paraffin (Test 33)
is an indication of the types of petroleum from which the residual
oil has been produced, regardless of the particular form of appa-
ratus in which the distillation has been carried out. Thus, residual
oils derived from non-asphaltic petroleums will contain ^from 4.0
to 15,0 per cent solid paraffin, those derived from semi-asphaltic
petroleums from a trace to 5.0 per cent, and those derived from
asphaltic petroleums from 0,0 to 0.25 per cent

RESIDUAL OILS

433

Fixed Carbon, Sulfur, Saturated Hydrocarbons and Proportion
Soluble in 88 Petroleum Naphtha. The following means may be
used to differentiate between residual oils derived from various

sources :

Residual Oils from:

Fixed
Carbon
(Test 19)

Sulfur
(Test 28)

Saturated
Hydrocarbons
(Test 34*)

Soluble 88
Naphtha
(Test 23)

U. S. non-asphaltic petroleum
U. S. semi-asphaltic petroleum
U. S. asphaltic petroleum
Trinidad, Venezuela and
Colombian petroleums

Per Cent
<5
<5

5-7

7-10

Per Cent
<i.S
<i.S

1.5-2.5

2 . 5-3 . 5

Per Cent

>75
50-75
30-40

30-40

Per Cent
> 9 o
> 9 o
80-95

80-95

Mexican petroleum

>io

3 5-5 o

30-40

80-95

The foregoing figures apply to the residual oils produced on
straight distillation as well as from the corresponding pressure-tars.

Flash-point and Volatile Matter. These two criteria are closely
related and interdependent. The lower the flash-point, the greater
will be the percentage of volatile matter, and vice versa. Both
fluctuate within wide limits in the case of residual oils. Excepting
for cut-back products, the flash-point of residual oils is generally
above 300 F. Cut-back products may run as low as 200 F., which
is likewise the case w r ith fuel-oils and undistilled pressure-tars.
Similarly the volatile matter at 500 F. in five hours will generally
run below 15 per cent or at most 20 per cent, except in the case of
cut-back products, which will run in excess of 20 per cent Where
residual oils are used to flux harder asphalts and asphaltites, or
where they are converted into blown asphalts, it is desirable that the
flash-point shall be as high as possible, (preferably above 450 F.)
and the volatile matter as low as possible (preferably below 3 or 4
per cent at 500 F. in five hours). On the other hand, if the re-
sidual oil is to be used for dust-laying purposes the presence of
volatile constituents is not detrimental, but on the contrary may be
desirable, and hence cut-back products will answer satisfactorily.
Residual oils produced from Colombian petroleum (asphaltic)
show the highest flash-point and the smallest amount of volatile
matter. In fact, Colombian petroleum is so difficultly volatile that
it must be distilled under vacuum after the lower boiling fractions
have been removed by topping in a shell or pipe still 28 Residual
oils produced from Venezuela and Trinidad (asphaltic) petro-
leums, also U. S. Mid-continental (semi-asphaltic) and U. S. Gulf-

434 PETROLEUM ASPHALTS XX

coast (asphaltic) show a somewhat lower flash-point and a corre-
spondingly greater amount of volatile matter. Residual oils ob-
tained from Mexican (asphaltic) and LJ. S. Californian (asphaltic)
petroleums show a still lower flash-point and greater quantity of
volatile matter .than the preceding, basing the comparisons on prod-
ucts of similar fusing-poihts and hardness (viscosity).

Residual oils from non-asphaltic petroleums are not produced
today in appreciable quantities, as this grade of petroleum is usually
distilled destructively to recover the lubricating oils and paraffin
wax. Moreover, such residual oils have certain inherent disadvan-
tages, including the fact that they are poor fluxes, they cannot be
blown successfully, and they contain a quantity of greasy and waxy
constituents which contaminate any other substances with which
they may be combined. Residual oils derived from asphaltic petro-
leums constitute the best fluxes and produce the most desirable
grades of blown asphalts. Those produced from pressure-tars will
show evidence of free carbon under the microscope and sometimes
also to the naked eye, and it is contended that unless used in ad-
mixture with other products, they are undesirable for producing
blown asphalts, since they are likely to result in a non-homogeneous
product. It is contended, however, that pressure-tars may be blown
with a mixture of air and steam at temperatures of 45-55 F-i
above which temperature carbon will be generated. 24 Any free
carbon may be removed by filtering the tar ; 25 by mixing the pres-
sure-tar with fuel oil, heating to 340 F. and either filtering or
centrifuging the mixture; 26 by treatment with sulfuric acid; 27 by
the addition of CaO during the cracking process, which results in
an agglomeration of the carbon and facilitates the filtration, 28

Another residual oil, which may suitably be used to flux harder
asphalts, consists in the semi-liquid residue produced in the refining
of lubricating oils with selective solvents. 29

Residual oils, with the exception of cut-back products, comply
with the following characteristics:

(Test i) Color in mass Brownish black to black

(Test la) Homogeneity to the eye Uniform to gritty

(Test it) Homogeneity under microscope Uniform to lumpy

(Test 7) Specific gravity at 77 F o. 85-1 .07

(Test Sa) Specific Engler viscosity at 140 F 10-50

(Test 9^) Penetration at 77 F 100-350

(Test 9*) Consistency at 77 F o- 7

(Test 15*) Fusing-point K. and S. method 20-100 F.

(Test 1 5*) Fusing-point R. and B, method 32-1 10 F.

(Test 16) Volatile at 325 F. in 5 hours fr-ia per cent

Volatile at 500 F. in 5 hours 1-10 per cent

XX RESIDUAL OILS 435

(Test 160) Residue of 100 penetration at 77 F. ob-
tained on evaporation 40-80 per cent

Ductility of residue at 77 F. (Test 100) . . 2-100 + cm.

(Test 170) Flash-point 300-550 F.

(Test 18) Burning-point 350-650 F.

(Test 19) Fixed carbon 2-10 per cent

(Test 21) Solubility in carbon disulfide 98-100 per cent.

Non-mineral matter insoluble o- i per cent

Mineral matter o- $ per cent

(Test 22) Carbenes o- I per cent

(Test 23) Solubility in 88 petroleum naphtha. . . . 80- 99 per cent

(Test 28) Sulfur Tr.- 5 per cent

(Test 30) Oxygen o- 3 per cent

(Test 33) Solid paraffins o- 15 per cent

(Test 340) Saturated hydrocarbons 30- 90 per cent

(Test 34^) Sulfonation residue 90-100 per cent

(Test 37*) Saponifiable constituents Tr.- 5 per cent

(Test 39) Diazo reaction No

(Test 40) Anthraquinone reaction No

Table XXXIV includes a few tests on typical residual oils ex-
clusive of cut-back products.

Pressure tars, also known as cracking-still tars have a smaller
percentage of hydrogen than the original charging stock, or fraction
thereof. Dehydrogenation is one of the steps by which such prod-
ucts are formed. The various steps include dehydrogenation, poly-
merization, condensation, intermolecular rearrangement, and vari-
ous combinations of these reactions. Polymerization and condensa-
tion, accompanied by dehydrogenation, account for the formation of
asphalt in the cracking process. It is of interest to note that asphalt
is formed in the cracking process from fractions of non-asphaltic
crude oils (e. g., Pennsylvanian), or semi-asphaltic crudes (e. g.,
Mid-continental) which are more paraffinic than asphaltic, and from
which asphalts are not otherwise produced in commercial quantities.
The formation of asphalts from paraffin-base oils (i. e., non-asphal-
tic) is a most striking example of the synthesis of asphalts from
paraffin hydrocarbons. 80

Table XXXV shows the characteristics of residual oils obtained
from cracking various fuel oils and topped crudes made by a so-
called flashing operation of the cracking process, in which the prod-
uct is withdrawn from the cracking still and transferred to a vapor-
izing chamber or zone of reduced pressure. This reduction in
pressure causes the vaporization of controlled amounts of the prod-
uct The residue withdrawn from the vaporizing chamber is termed

436

PETROLEUM ASPHALTS

M *&

ffl

O O

MOO

o d d

S "<S

On M W "t

*l 10 to

tO O> <-O

00 O to Ti- O

<*+

OV N ^

9k H O t*

d O *i

O O

00 O

<y o d

00 M 00

M O I 1 *

00 M

H d

M O VJ

n O oO 00

to O fr
O O O

-i- 10 M* to (O

MOO

4 d d

w *- "* N

to O to
00 4

to O
*O 00 fO *0 fr

00 WO *-

en O O M

Cft O%

VO O

oo w o oo

j d a

to O

? d

(JO

MO CT>

o o o

VO O> O

O 1 *

M d to

C/3

VO O O
Jf* O <O

Tt- to t

o o o

O O M

to to

en MO oo
gl 6 d ^

00 O

to d

O MO M

cr o O *

9k O^

00 M M

d t^id

O O O <O

8 d i

Thermal Tests:
Fusing-point (K. and S. m
deg.F
Fusing-point (R. and B. m
deg.F
Volatile, 500 F., 5 hrs., per
Flash-point, deg.
Fixed carbon, per

to *O S. <

M H H

RESIDUAL OILS

437

"flashed residue." The yield of pressure tar based on the weight
of charging stock depends upon the character of the oil treated.
The particular examples given range in yield from 10 to 20
per cent.

TABLE XXXV
ASPHALTS PRODUCED FROM FLASHED RESIDUES

Property

Kentucky*

Midcontinent and West
Texas

Midconti-
nent
Gushing

Midconti-
nent II

Coating
Asphaltt

Asphalt
Cement t

Specific gravity at 25 C. (77 F.)

i 075
231 (448)
0.58
48
S3 (127)
680
93-8
99-1
5-3
17.2

IOO
>I22
>I22

1.065

1.099

1.0867
171 (340)
0.765
54
54 (129)

I2IO
91.2
98.7

3 6
17-8
97
78

1.1195
177 (35o)
1. 15
49
5i (123)
693
92.7
99.8
2.17

20.2

103

>I22
>I22

FlocK P f F ^

Loss at 163 C (325 F,), per cent

Trace

4-0
126 (259)

1-7

Penetration of residue at 35 C. (77 F.), mm
Softening-point C ( F.)

55 d3i)
829

Flnnt tf>*t at CO C* ^T22 F 1 SCC

^nliihflitv in PPL ner cent

96.9
98,6

Solubility in CSg

97-9
2.63

20.0
IOO

I2S
63

I9.O
5-5
o.3

Penetration at 25 C. (77 F.), mm
Ductility at 25 C (77 F.) cm

DnrHlitv at rfi P f6o F } cm < . . . .

* 100-120 mm, penetration for macadamized roads.

t Coating asphalt, air-blown for 3 hours at 254 C. (490 F.).

t Asphalt cement for use in asphalt macadam pavements.

85-100 mm. penetration for macadamized roads.

|J 100-120 mm. penetration used in building asphalt concrete roads or macadam roads.

Table XXXVI gives a comparison of the properties of the as-
phalt derived from a cracked Gushing topped crude, by steam-dis-
tillation and air-blowing, respectively.

TABLE XXXVI

PROPERTIES OF ASPHALT MADE FROM GUSHING TOPPED CRUDE BY STEAM DISTILLATION AND

BY AIR-BLOWING

Property

Residue
from Steam
Distillation

Air-blown
at 232 C.
(450 F.)

Flashed residuum per cent

71.5

70.2

^Jrvfr^nincr ooint C. ( F.}

51 (124)

63 (146)

Penetration at 25 C. (77 F.), mm. . ,
Ductility at 2< C. (77 F.), cm

105

93
11.3

^nlnWlifv in CS oer cent

IOO

100

Solubility in CCli. per cent

99.3

99-5

438

PETROLEUM ASPHALTS

Table XXXVII similarly compares the properties of asphalt
derived from the flashed residuum from a cracked Pennsylvania
kerosene distillate by steam-distillation and air-blowing, respectively.

TABLE XXXVII

PROPERTIES or ASPHALT MAI>E FROM PENNSYLVANIA CRUDE BY AIR-BLOWING AND STEAM-

% DISTILLATION

Property

Cracked Residuum

Air-blown

Steam-distilled

Per cent asphalt recovery

5.26
1.099
103
5i (1^3)
38i
125
0.67
60

202 (395)

21 8 (425)

99-59
97.71
None

5-09
1.116
105
44 (112)
297
125
0.7
70
i 88 (370)
207 (405)
99.86
98.95
None

Specific gravity at 25 C, (77 F.)

Penetration at 25 C. (77 F.), mm

Softening point (ring-and-ball), C ( F.)

Float test) sec

Ductility at 25 C. (77 F.) cm

Volatility at 163 C. (325 F.), per cent

Penetration of residue at 25 C, (77 F.), mm

Flash point (Cleveland open-cup), C. ( F.)

Fire point (Cleveland open-cup), C. ( F.)

Solubility in CS2, per cent

Solubility in CCU, oer cent

Water

Such asphalts may be produced to meet specifications for roofing
or shingle saturants, coating asphalts for composition roofings,
floorings, blowing stock, emulsions, etc. For a given stock, the
pressure tar obtained from a cracking coil operated at 250 Ib. per
square inch will be less asphaltic than a tar obtained from the same
unit operated at 750 to 1000 Ib. per square inch. In no case is a
present-day cracking unit operated under conditions where appre-
ciable quantities of free carbon is formed.

The outstanding features of high temperature-pressure conver-
sion residues are as follows :

(1) Up to a certain point, the higher the temperature and
pressure, or the longer the time element, the more asphaltic will be
the residue obtained.

(2) Cracking-coal residues of a given fusing-point have a
higher specific gravity, ductility and susceptibility to temperature

RESIDUAL OILS

439

changes, likewise lower viscosity than equivalent residues produced
by direct distillation processes.

(3) Cracking-coil asphalts are less soluble in petroleum naph-
thas than straight-distilled residues produced from the same crude.

Straight-reduced asphalts from cracking processes resemble
coal-tar pitch in certain physical properties, f^ince they have ex-
tremely low viscosity when melted and produce cut-backs and
primers that are if anything superior to coal-tar products. 81 Inci-
dentally, pressure tars are completely miscible with coal tars and
coke-oven tars. 32

The following figures 8a show the characteristics of residual oils
derived from various sources, as well as sundry mixtures :

TABLE XXXVIII

Hi a

C "H

Nature of OU

S 8

* w

3 h

S i

C/5 o

.S jg

.sj

H ^j
*J U

12 S

C/3

cfl

Straight-run residual oil from U. S. non- f
asphaltic petroleum (paraffin base) . . . j

Light
Medium
Heavy

0-933
0.939

o 939

13-7

21 4

31.5

99.9

99 9
99 6

1.4
2.9
1,4

190

210
238

0.7
0.7
0.45

66
68

13
22

Straight-run residual oil from Arkansas f

Light

o 980

13 8

99-6

ii. 9

130

7-9

semi-asphaltic petroleum blended with <

Medium

I 002

23.9

99-6

14.0

I2S

9-7

pressure-tar derived from ditto I

Heavy

i .013

30.1

98.8

16.4

134

4-5

Pressure-tar derived from U. S. non- f

Light

1.030

13.6

99-9

n. 8

170

2.7

100 4-

asphaltic and semi-asphaltic petrole-j

Medium

1.045

189

99 9

12.4

l85

ioo-f

Heavy

1.056

32.3

99 9

14.2

195

x.6

100+

Pressure-tar derived from U. S. non- (

Light

0.938

10.3

99.6

5-1

165

4-1

asphaltic and semi-asphaltic petroleum {

Medium

0.944

16.1

99.6

6.3

180

1.9

Mixture of straight-run residual oils de- f
rived from Mexican asphaltic petrole-j
um and U. S. non-asphaltic petroleum I

Light
Medium

0.947
0.959

13.2
23.8

99 9
99-6

5.7
10. S

150

126

5.2
6.1

57
64

Straight-run residual oil from Mexican

Medium

0.963

23.5

99.9

15.6

105

5-6

xoo-t-

Cut-back residual oil from Mexican petro-

Light

0.961

15.6

99-8

14.9

15.2

440 PETROLEUM ASPHALTS XX

BLOWN PETROLEUM ASPHALTS

These are manufactured from residual oils derived from as-
phaltic, semi-asphaltic or non-asphaltic petroleums, by blowing with
air at elevated temperatures.

It has been recognized for many years that petroleum products
become changed in their physical properties by treating with oxi-
dizing agents or air. One of the first to report this was Abraham
Gesner in i865, 84 who remarked that:

"Organic substances are oxidized by the atmosphere, and its
action promoted by a high temperature. Hot air has therefore
been forced through hydrocarbon oil during the process of purifi-
cation, and in some instances with advantage.' 1

In 1876 W. P. Jenney patented the process of treating sludge
oil obtained in refining petroleum with sulfuric acid, with a current
of air at a temperature of 250 C. 85 He observed that a resinous
substance was produced by the absorption of atmospheric oxygen
by the oil.

De Smedt patented a process for oxidizing coal tar with potas-
sium permanganate or permanganic acid at a temperature of
300 F., 8 * also the method of oxidizing petroleum residues in a
similar manner, 87 or by distilling petroleum in the presence of an
oxidizing agent. 3 *

Next Schall 8 * discovered that paraffin, vaseline and heavy min-
eral oils oxidize rapidly and almost completely by introducing a
well-divided stream of oxygen at 140-150 C., especially in the
presence of insoluble manganese compounds. Dorsett oxidized coal
tar by heating with manganese dioxide and ammonium chloride. 40
Baillard oxidized a mixture of petroleum and oleic acid by means
of air at 160 C. 41 Busse blew air through a heated mixture of
asphalt and vegetable oils in the presence of nitric acid, sulfur, or
sulfur dichloride. 4 * Salathe blew heated air through melted native
asphalt, either alone or in the presence of manganese dioxide or
litharge. 48 Schreiber proposed blowing melted asphalt, coal-tar
pitch, fatty-acid pitch, wool-fat pitch, etc., with air in the presence
of manganese dioxide, with or without the addition of sulfuric acid,
and finally adding formaldehyde. 44 Incidentally, it is of interest to
note that vaseline, liquid or solid paraffin wax may be converted into

XX BLOWN PETROLEUM ASPHALTS 441

fatty acids by oxidation with potassium permanganate in acid or
alkaline solution, or with a mixture of potassium permanganate and
sodium hypochlorite, or a mixture of manganese dioxide with hydro-
chloric or nitric acid. 45

The first to manufacture blown asphalt on a commercial scale
was F. X. Byerley, who obtained a patent in i894 46 for drawing
air through petroleum residues (and especially those derived from
Lima, Ohio, crude oil), at temperatures between 400 and 600 F.
In this way he obtained "pitches" of variable properties depending
upon the temperature and the duration of the blowing process. For
the softer grades (fusing under 200 F,), the Lima residuum was
blown three days at 400 F., during which 2 per cent of distillate
was produced. For the harder grades (fusing at about 400 F.)
the residuum was blown four to five days at 500 F., during which
between 5 and 6 per cent of distillate was recovered. The product
was claimed to be resistant to changes in atmospheric temperature,
and to differ from the corresponding steam-distilled asphalt by being
readily soluble in petroleum benzine or naphtha. Byerley marketed
the product under the name of "byerlite." Air under suction was
passed through a 6000 gal. still of the oil, at the rate of 450 cu. ft.
per minute. Ohio petroleum residue of 21 to 27 Baume, also
Texas Gulf-coast residue of 12 to 15 Baume were first used for
this purpose.

J. W. Hayward 47 and also G. F. and G. C. K. Culmer 4 * ob-
tained patents for a similar process, according to which a mixture
of petroleum residue and refined Trinidad asphalt or gilsonite is
heated to 193 C. and blown for forty hours at the rate of 15 to
30 cu. ft. air per minute, per ton asphalt. After a time the external
source of heat was removed, since it was found that the temperature
of the residue increased spontaneously, due to the chemical changes
induced by the action of the air. It was also found that the oxida-
tion progressed very rapidly at first, and then more slowly, as it
approached the end of the process.

According to present practice, the residual oil is blown at 525 to
575 F. at the rate of 30 to 50 cu. ft air per minute, per ton of
asphalt, for a period of five to twelve hours. It is found unneces-
sary to use any of the catalyzers referred to in the earlier patents.
The air may either be blown through the still under pressure, or

442 PETROLEUM ASPHALTS XX

else sucked through the still by subjecting the contents of the still
to a partial vacuum (up to 20 in. mercury). There are proponents
of both systems. The loss depends largely upon the amount of
volatile matter contained in the residual oil, and varies from prac-
tically o up to 10 per cent of the weight of the charge, depending
of course upon the extent the' product is blown. Water and carbon
dioxide are also given off. It is contended that the vacuum process
removes the oily and greasy matters from the residual oil and forms
a brighter and cleaner looking blown asphalt. The more asphaltic
the crude from which the residual oil was derived, the better will
be the quality of the blown product, and the shorter the duration
of the blowing process. Residual oils derived from semi-asphaltic
and non-asphaltic petroleums must be blown longer to obtain a prod-
uct of the same fusing-point, and the blown asphalt is apt to appear
quite oily and greasy. Non-asphaltic petroleums will yield a good
grade of blown asphalt if first subjected to a high temperature and
pressure, which serve to convert saturated hydrocarbons into poly-
merized unsaturated compounds. 40 Blown asphalts may likewise
be produced from naphthenic residual oils or naphthenic derivatives
i.e., non-asphaltic and non-paraffinic in character) obtained by ex-
tracting petroleum with SO 3 , aniline, phenol, etc. 60

The best blown asphalts are produced from the following pe-
troleums, viz. : U. S. Gulf-coast field (Texas) ; Mexican heavy vis-
cous crudes of 8 to 15 Baume obtained from the Panuco and To-
pila regions (20 to 30 miles southwest of Tampico), also from
the Ebano region (40 miles west of Tampico) ; Venezuela crudes
from the Lagunillas, La Roza and Mene Grande fields; Colombian
crudes from the Barranca-Bermeja region; likewise from Trinidad
crudes.

Mid-continental (U. S.) semi-asphaltic petroleums form re-
sidual oils which when blown at 450 to 475 F. for nine to ten
hours produce blown asphalts having a fusing-point of 350 to
400 F. (R. and B. method) and without the formation of "free
carbon/' If a small proportion of gilsonite is added to the mix-
ture, the time of blowing will be increased, but the product will be
improved materially in the following respects: it will be harder,
have a higher gloss, greater cohesiveness, greater ductility, lower
susceptibility to temperature changes, and improved weather-re-

XX BLOWN PETROLEUM ASPHALTS 443

sistance. The use of grahamite does not give as satisfactory results,
since the product will be lacking in ductility,

California residual oils produced from asphaltic petroleums
when blown at 425 to 450 F. for twelve to eighteen hours will
produce blown asphalts having a fusing-point of 175 to 190 F.
(R. and B. method). If the temperature exceeds 530 F, free car-
bon will be formed. Blown California asphalts have a good gloss
and are considerably harder than Mid-continental, Gulf-coast
(Texas), Mexican, Venezuelan, Colombian and Trinidad products.
They are also more susceptible to temperature changes.

Texas residual oils derived from asphaltic petroleum produce
excellent blown asphalts that are glossy, resistant to temperature
changes, free from oily or greasy constituents, highly ductile, and
are excellent weather-resistants,

Mexican, Venezuelan, Colombian and Trinidad asphaltic petro-
leums produce residual oils which behave similarly on blowing. Such
residual oils having a fusing-point of 90 to 100 F. (R. and B.
method) when blown at 450 to 500 F., for six and one half to ten
hours, at the rate of 40 cu. ft. air per minute, per ton, will produce
blown asphalts having a fusing-point of 220 to 235 F. (R. and B.
method) and a penetration at 77 F. of 15 to 17. The resultant
asphalts have a good gloss, are free from oily constituents, moder-
ately ductile and fairly resistant to temperature changes.

A method has been patented for blowing a mixture of topped
Mexican residuum (8 to 10 Be.) with topped Mid-continental re-
siduum (12 to 14 Be.) derived from Illinois semi-asphaltic petro-
leum, at 450 to 500 F., which is claimed to result in a product of
greater ductility than when Mid-continental residuum is used alone. 61

Various catalyzers and oxidizing agents have been proposed for
augmenting the air-blowing process, including : manganese dioxide ; 52
manganese dioxide and nitric acid; 53 finely powdered limestone; 54
caustic soda or sodium carbonate; 56 bentonite or finely powdered
coke ; 56 sulfur ; 67 sulf uric acid with or without the addition of metal-
lic persulfates or perborates; 58 boric acid, phosphorus acid or ar-
senious acid; 69 potassium chlorate; 60 chlorides or sulfates of zinc,
iron, copper or antimony; 61 basic acetylacetonate of manganese, ce-
rium, nickel, cobalt or zinc; 62 copper, iron, manganese or cobalt
soaps; 68 as well as the various agents referred to previously. It

444

PETROLEUM ASPHALTS

has been proposed that any excess catalyzer be removed after the
blowing operation by boiling the product with dilute hydrochloric
acid and washing with hot water. 64

The use of various gases has been suggested for blowing
through the melted asphalt, including: air alone; air under super-
atmospheric pressure ; 65 air followed by a mixture of air and steam
in varying proportions under atmospheric or reduced pressure; 66
carbon dioxide with or without air; 6T ozone; 6 * a mixture of air or
oxygen with NO 2 or SO 2 ; 69 carbon monoxide activated by a cata-
lyst such as nickel or palladium, or by first heating the asphalt with
cerium oxide or tin oxide and blowing as aforesaid; 70 air containing
up to 1 1 y 2 per cent chlorine ; 71 chlorine followed by carbon diox-
ide ; 72 bromine or boron fluoride ; air and halogens in the presence
of sulfur; 73 etc.

It has been shown that the use of air containing up to 1 1 T / 2
per cent of chlorine for blowing asphalts maintained at 475 F.
speeds up the process, and that chlorine is both absorbed and com-
bined chemically with the asphalt. The fusing-point is increased
more rapidly, and the ductility and penetration are decreased more
rapidly than when air alone is used. Thus, with a residual oil hav-
ing a fusing-point of 86 F. (R. and B.) and a penetration of 253
at 77 F. (50 grams in 5 seconds), the following relative blowing
times were required:

To increase the

To decrease the

Fusing-point

Penetration

Ductility

to 200 F.

(50 g./5 sec./

at 77 F.

(R. & B. method)

77 F.) to 20

to 10 cm.

22 hrs.

1 8 hrs.

19 hrs.

Air with 1 ,3 per cent chlorine

1 8 hrs.

15 hrs.

14 hrs.

Air with 6 o per cent chlorine

8 hrs.

5 hrs.

5i hrs.

Air with 1 1 2 per cent chlorine. ....

5 hrs.

3 hrs.

3i hrs.

The blowing operation may either be intermittent or continu-
ous/ 4 In the intermittent or batch process the apparatus consists
essentially of an open, or preferably closed cylindrical still in which
the air or other gas is introduced through a series of perforated
pipes at the bottom. Various means have been suggested to sub-
divide the gas into fine streams or jets, 76 or to accomplish a more

XX BLOWN PETROLEUM ASPHALTS 445

intimate mixing of the elements by rapidly agitating the asphalt in
a closed vessel through which a current of air is passed. 76 Con-
tinuous processes involve the following expedients: circulating the
asphalt through a horizontal still divided into compartments into
which air is blown individually; 77 circulating the asphalt through
a series of stills into each of which air is blown; 78 passing the as-
phalt in conjunction with a stream of air through a tube-heater; 79
flowing or spraying the melted asphalt through a chamber in which
a counter-current of air is passed. 80

Various mechanical expedients have been suggested to facili-
tate the blowing process, including the following. To conserve fuel,
the freshly distilled residual oil, before it is permitted to cool, is
blown in a heat-insulated still without the application of external
heat. 81 Constant temperature is maintained during the blowing
operation by a thermostatically controlled cooling device. 82 To
prevent further oxidation of the blown product while still at a high
temperature, it is maintained in contact with an inert gas. 83 De-
vices for condensing and returning to the still any vapors that are
evolved during the blowing process. 84 Recirculating the air as well
as any evolved vapors through the charge in a closed system. 85 The
blown product may be "stabilized" by maintaining at a high tem-
perature for 24 hours. 86

The use of different mixtures has been suggested for the pur-
pose of improving the characteristics of the finished product, in the
way of imparting rubber-like properties, greater toughness, increas-
ing its resistance to temperature changes, augmenting its weather-
resistance, etc., including the following: a mixture of semi-asphaltic
residual oil and fatty-acid pitch, with or without gilsonite; 87 a mix-
ture of residual oil, pine tar and rubber; 88 a mixture of residual
oil or residual asphalt with vegetable drying oil; 89 a mixture of
residual asphalt with cylinder oil stock; 90 a mixture of gilsonite with
cylinder oil stock; 91 asphalt mixed with the high-boiling point, SO 3
insoluble residue derived from the Edeleanu extraction process; 92
a mixture of asphalt with pressure tar (cracking-still residue) ; 98 a
mixture of sludge asphalt neutralized with magnesium oxide; 94
blowing an aqueous-clay dispersion of residual oil with metallic
driers at a comparatively low temperature. 95

Blown asphalts vary in consistency from semi-liquids to moder-

446 * PETROLEUM ASPHALTS XX

ately hard solids at room temperature. They are marketed under
various proprietary names such as Byerlite, Sarco, Hydrolene, Tex-
aco, Parolite, Korite, Stanolind, Obispo, Ebano, etc.

The advantages of "blowing" over the steam-distillation process
are as follows:

(1) The yield of asphaltic residue from the blowing process
is mucn greater than when steam distilled.

( 2 ) Blown petroleum asphalts are less susceptible to tempera-
ture changes than steam distilled products, and in addition acquire
a certain amount of elasticity and resilience, usually termed "rubber-
like" properties. Upon comparing a residual asphalt with a blown
product of the same fusing-point, it will be found that the latter is
considerably softer, as evidenced by its consistency or penetration.
Conversely, upon comparing a residual asphalt with a blown prod-
uct of the same hardness or penetration, the fusing-point of the
latter will be found to be considerably higher.

(3) In many cases it is possible by blowing to obtain a residue
of better quality than if the steam-distillation process were used, and-
in fact the blowing process renders many crude petroleums available
which could not otherwise be used for preparing high fusing-point
asphalts. Non-asphaltic petroleum will produce fairly good as-
phalts when blown, whereas the same crude will produce worthless
residual asphalts by the steam distillation process.

(4) It is easier to control the "grade 11 of asphalt by blowing.
As previously noted, the progress of blowing is more rapid at the
start of the process than towards its conclusion. In other words,
the blown asphalt is said to "come to grade" very slowly. With
steam distillation, the alteration is much more marked at the end
of the distillation process, so that the steam-distilled asphalts "come
to grade" very rapidly. In attempting, therefore, to produce a resi-
dual asphalt of a definite fusing-point or hardness, the blowing proc-
ess is preferable, since it may be controlled to better advantage.

Figure 129 shows the effect of prolonging the blowing process
(at 425 F.) on the fusing-point (Ring and Ball method, Test 15*),
and penetration (needle penetrometer, test 9^) of a topped mixed-
base petroleum. 96 The ductility-fusing-point curve is almost a
straight line for residual asphalts derived from the same crude oil,
whereas in the case of blown asphalts a decided break or change in
direction is found to occur. 97

Figure 130 illustrates the consistency, tensile strength (multi-
plied by 10) and ductility curves of a typical blown petroleum as-

BLOWN PETROLEUM ASPHALTS

447

phalt produced from mid-continental petroleum, having a fusing-
point of 127 F. (K. and S. method).

The care with which blown asphalts are prepared largely influ-
ences their physical characteristics. When made from improper

280

320

300

260

240

C 220

.2200

2 100

160

5 140

a 120

100

to,

18 20 22 24 26 26 30 32 34 36 36 40 42
Hours Blown

..-/Va ? Needle, lOOg, 5s, 777T

10 12 14 ie

is eo 32 e4 ^& ee 30 32 34 3& 33 40

Hours Blown

From "Good Roads"

FiO. 129, Effect of Blowing on the Fusing-point and Hardness of Petroleum Asphalt.

crudes or by careless treatment, blown asphalts are apt to have
certain defects, viz.:

(i) When made from non-asphaltic or semi-asphaltic petro-
leums, they are likely to present a "greasy" surface, and especially
on standing a few days, due to the partial separation of vaseline- or
paraffin-like bodies. Blown asphalts made from asphaltic crudes

448

PETROLEUM ASPHALTS

do not behave in this manner. The oily constituents and wax may
be separated by first treating the crude petroleum with a selective
solvent, as for example propane, 08 or liquid SO 8 , aniline, phenol,
etc.," distilling off the solvent and blowing the residue in the usual
manner. It is also claimed that these objectionable constituents may
be eliminated if the asphalt is blown with air containing ammonia

gas

100

( 2 ) Blown asphalts, and especially those of high f using-point,
have the disadvantage of being "short," or in other words, they lack
ductility. By carefully regulating the process, this defect may be
minimized, particularly if the asphalt is subjected to a moderate
amount of blowing. It is a fact, however, that the longer the blow-
32* 77* N5*

90
60
70

50
40
30.
3D
10

LE6END

Hardness

Tensile
Stren <gthfric)

Ductility
O Fusing font

---*.

'>*

" I

>~'ll,,^.

ifnr

1 ~-

10 eO 30 40 50 60 70 60 90 100 110 120 130 140 150 160

Temperature , Degrees Fahrenheit
FIG. 130. Physical Characteristics of Blown Petroleum Asphalt.

ing is continued, the less ductile will be the asphalt The ductility
of the product may be decidedly improved by adding to the base
material a proportion of the product derived from the Edeleanu
extraction process (L e., hydrocarbons soluble in liquid SO 2 ) and
blowing the mixture. 101

(3) Asphalts when over-blown, or blown at too high a tempera-
ture, show a separation of non-mineral matter insoluble in carbon
disulfide, and a large percentage of carbenes. The former may
readily be detected under the microscope (see Test 2&), also in cer-
tain aggravated cases by the eye, by presenting a dull surface upon
being disturbed (see Test 2a).

When the blown asphalts first appeared on the market, they
unfortunately did not enjoy a good repute, but their quality has

XX BLOWN PETROLEUM ASPHALTS 449

improved to such an extent, that blown asphalts may now be pro-
cured of almost any fusing-point up to 400 F M which are not only
more resistant to temperature changes, but are at the same time as
ductile as any unblown product of the same "grade" (L e., fusing-
point or hardness at 77 F.).

f ln general, blown asphalts comply with the following charac-
teristics :

(Test i) Color in mass Black

(Test 2#) Homogeneity to the eye at room temperature Uniform to gritty

(Test 2^) Homogeneity under the microscope . . Uniform to lumpy

(Test 3) Appearance surface aged indoors one week. . . Bright to dull and greasy

(Test 4) Fracture Soft grades do not show a

fracture, hard grades
present a conchoidal
fracture

(Test 5) Lustre Bright to dull

(Test 6) Streak on porcelain Brownish black to black

(Test 7) Specific gravity at 77 F o. 90-107

(Test 9^) Penetration at 77 F ' 25-200

(Test 9^) Consistency at 77 F 2-30

(Test gd) Susceptibility index 8-40

(Test 10) Ductility Variable

(Test n) Tensile strength Variable

(Test 15*) Fusing-point (K, and S. method) 80-400 F.

(Test i$) Fusing-point (R. and B. method) 100-425 F.

(Test 1 6) Volatile matter, 500 F. in 5 hours 1-12 per cent

(Test 170) Flash-point 35o~55o F,

(Test 18) Burning-point 400-650 F,

(Test 19) Fixed carbon 5- 20 per cent

(Test 21) Solubility in carbon disulfide 95-100 per cent

Non-mineral matter insoluble 0-5 per cent

Mineral matter o-J per cent

(Test 22) Carbenes o-io per cent

(Test 23) Solubility in 88 petroleum naphtha 50-90 per cent

(Test 25) Water Absent

(Test 28) Sulfur Tr - 7. 5 per cent

(Test 30) Oxygen 2- 5 per cent

(Test 33) Solid paraffins o- 10 per cent

(Test 340) Saturated hydrocarbons 30- 75 per cent

(Test 34^) Sulfonation residue 90-100 per cent

(Test 37*) Saponifiable constituents Tr.- 2 per cent

(Test 39) Diazo reaction No

(Test 40) Anthraquinone reaction No

Figure 131, plotted by the author from hundreds of determina-
tions, shows the relation between the specific gravity and fusing-
point of residual oils, blown asphalts and residual asphalts.

Residual oils range in specific gravity from 0.85 to 1,07 at 77
F., and in fusing-point (K. and S. method) from 20 to 100 F.;

450

PETROLEUM ASPHALTS

blown asphalts range in specific gravity from 0.90 to 1.07, and in
fusing-point from 80 to 400 F. ; residual asphalts range in specific
gravity from i.oo to 1.17 and in fusing-point from 80 to 225 F.
The chart shows that residual oils verge into the residual and blown
asphalts respectively, and it also graphically illustrates the differ-
ence between the residual and blown asphalts. It will be observed
that the effect of blowing is to increase the fusing-point and decrease
the specific gravity of the product

Another method for distinguishing between blown and residual
asphalts, devised by the author, consists in finding their hardness
by means of the consistometer (Test gc) at a temperature exactly

20 100 225 300 400

Fusing Point, Degrees Fah.

FIG. 131. Relation between the Specific Gravity and Fusing-point of Residual Oils,
Blown Petroleum Asphalts and Residual Asphalts.

50 F. lower than their fusing-point by the K. and S, method. Blown
asphalts show a hardness of less than 15, whereas residual asphalts
show a hardness greater than 15 under these conditions. This is
illustrated by the examples given in Table XXXIX.

It is of interest to note in connection with the foregoing figures,
that for any particular crude, the hardness at the " fusing-point less
50 F." decreases with the extent of the blowing, but remains practi-
cally constant in the case of the residual asphalts, regardless of the
extent to which the distillation may have been carried.

Blown asphalts, due to their greater softness, and correspond-
ingly large proportion of "life-giving" constituents, are better
weather-resistants than residual asphalts derived from the same
crude, having the same fusing-point and showing the same propor-

BLOWN PETROLEUM ASPHALTS
TABLE XXXIX

451

Fusing-point,
(Test 15*)

Hardness (Test 9^) at
50 F. below the
Fusing-point

Blown Petroleum asphalts:
Lima, grade 120

QI . r F.

Hd. at 41.5 F. = n 2

Lima, grade 1 50

Hd. at 105 o F. =* 10 i

Lima, grade 185

* j j

214.

Hd. at 164 o F. ~ 78

Lima grade 285 .....

271 C

Hd. at 221 5 F = 67

Mid-continental, grade 115, .
Mid-continental, grade 180. .
Mid-continental, grade 215. .
Residual asphalts:
California, grade E,

* 1 * O
100
164
215

Hd. at 50.0 F. - ii 9
Hd. at 114.0 F. 10.3 '
Hd. at 165.0 F. = 8.4

Hd, at 40.0 F. = 21.5

California, grade DE . . ....

108

Hd. at 58 o F. =* 22 2

California, grade D

124

Hd. at 74.0 F. = 22 2

California grade C

146

Hd. at 96 o F = 22 9

California, grade CB

168.5

Hd. at 118.5 F, = 23 5

California, grade B

2OQ

Hd. at 159 o F = 22 9

Mid-continental, grade 140. .
Mid-continental, grade 180. .

119.5
158

Hd. at 69,5 F, = 21.5
Hd. at 108.0 F. 21.5

tion of volatile matter. They are about equal in weather-resistance
to residual asphalts of the same hardness prepared from the same
crude, and far superior to sludge asphalts regardless of their hard-
ness or fusing-point. It is a mooted question whether the native
asphalts or the blown asphalts excel in weather-resisting properties,
and to which in the author's opinion no categorical answer may be
given.

It has been observed that blown asphalts have a higher saponifi-
cation value than residual asphalts, upon comparing grades of the
same fusing-points. 102 Three samples of the same product tested
as follows:

Fusing-point
(K. and S.)
(Test 1 50 )

Acid Value
(Test 37*)

Saponification
Value
(Test 37</)

Sample No. i

70 C,

O.OT

12. O<

Sample No, 2

100 C.

O.O7

18.

Sample No. 3

icoC.

O.O'l

42.O

It is concluded that the saponification value of asphalts is in-
creased by blowing, in a manner similar to that observed with

452 PETROLEUM ASPHALTS XX

paraffin waxes, etc., and that ester-like bodies and anhydrides are
produced during the blowing process. On the other hand Edmund
Graefe 108 ascribes the high saponification values (some of which
he found to be as high as 60) to the presence of sulfuric acid in the
blown asphalt. He points out that all asphalts normally carry sul-
fur in combination, and that in some of them, e. g., Mexican as-
phalts, the sulfur is loosely combined with the associated hydrocar-
bons, so that during the blowing process this loosely combined sulfur
unites with the oxygen of the air introduced into the heated asphalt,
forming sulfuric acid. He predicts that if this sulfuric acid re-
mains in the asphalt, it is apt to cause its disintegration upon ex-
posure to the elements. Graefe also reports that the oily distillate
condensed during the blowing process will combine with strong
alkalies, which when neutralized with mineral acid forms a light col-
ored, stringy resinous mass. On the other hand, it has been claimed
that the weather-resistance of blown asphalts may be improved by
treating the product with a 10 per cent solution of hydrochloric
acid. 104

Table XL includes the results obtained by the author upon
examining representative blown asphalts derived from different
crudes and blown to different extents.

SULFURIZED ASPHALTS

The process of treating asphalt with sulfur was first disclosed
by A. G. Day 105 and subsequently by J. A. Dubbs 106 who heated
Pennsylvania, Lima and Ohio residuums with 20 to 25 per cent of
sulfur, at a temperature somewhat below the boiling-point of sulfur,
until the evolution of gas ceased. The resulting product is very
similar in its physical properties to blown asphalt, being only slightly
susceptible to temperature changes, but it is still further lacking in
ductility. Thirty years ago, asphalt treated in this manner was
exploited under the name "Pittsburgh Flux." This was before
blown asphalts appeared on the market, which on account of their
smaller cost of production, soon displaced the sulfurized product.

Processes have been described involving the vulcanization with
sulfur of the following classes of bituminous products: native
asphalts; 107 native asphalt (e. g. Trinidad) mixed with vegetable
oils; 108 native asphalt (e. g- Trinidad) fluxed with fatty-acid

TABLE XLI. CHARACTERISTICS OF TYPICAL RESIDUAL ASPHALTS

No.

Test

From Semi-asphaltic Petroleum

From Asphaltic Petroleum

Mid-continental

Mexican

California

Gulf-coast

Trinidad

Venezuela

Japan

za
ib
3
4
5
6
7

9 b
ge

9 d
lob

Physical Characteristics:
Homogeneity to eye at 77 F
Homogeneity under microscope
Appearing surface, aged 7 days

Homo.
Homo.
Dull
Conch.

Homo.

Dull
Conch.

Non-horn.
Lumpy
Dull
Concli

Homo.
Gritty
Bright
Conch.

Homo.
Homo.

Bright
Conch.

Homo.
Gritty
Bright
Conch

Homo.
Homo.
Bright
Conch

Gritty
Bright
Conch

Non-horn.
Lumpy
Bright
Conch

Homo.

Bright
Conch

Bright

Homo.
Bright

Homo.
Homo.
Bright
Conch

Bright
Conch.

Homo,
Homo.
Bright
Conch.

Homo.
Homo.
Bright

Fracture

Lustre
Streak
Specific gravity at 77 F

Bright
Black

1.050

Bright
Black

1.078

Bright
Black
1. 1 19

SI. dull
Black
1.145

Bright
Black
1.015

Bright
Black
1.024

Bright
Black
1.036

Bright
Black
1 .065

Bright
Black
1.095

Bright
Black
1.113

Bright
Black
1.127

Bright
Black

1.158

Bright
Black

I .022

Bright
Black
1-033

'Black'

1.095

Bright
Black
i . 1 20

Bright
Black

1.082

Bright
Black

'Black'

Mechanical Tats:
Penetration at T 1 5 F
Penetration at 77 F

88
37
9.5

5.1

15-2

66.9

Si-7
37
19

O.I

2.7
15.0

45
21

5
9.6

23-5
81.4
50.5
64.5
IO

0.35

4-2
9-5

12.5
3-5

27.1
5-5
107.0
48.0

47-9
88.8

>100

> 45

132
32

3-1

24
8

4-5

7
6.5

70
24

6.8

28
15
6
'3-9

ii -5
3

28.8

8
i
o
38.0

o
45-1

48
19
M

8.2

4P
9
IO

10.4

20
12

8.8

2
O
27.2

78
26
7
6.0

2O. 2
72.1
46.5
42
2O

0.8
4.1

IO.O

9-4
26.6

>IOO

> 50

22
15

1.6

6.2

13-4

Soft
93
16

2.8

6.1
51.0
41.9

IOO
12

Consistency at 1 1 5 F

Consistency at 32 F
Susceptibility index
Ductility in cms. at 1 1 5 F
Ductility in cms. at 77 F

60.4

47-3

68.0
47-8

73-0
46.5

6 4 .6
4 6.6

57
9

0.6

3-5

10.

78.3
44.0
12.5

1.65

6.2

12.0

> 42

8.0

3-95
5-
8.0

> IOO

> 40

o
3-4
4.0

5-2

>100

> 45

o
4.25
4.2

3-7

56.3

32.0
50
28

3.8

5-2
12. O

65,1

29.2
32
15

5.5

7.0
18.0

*8. 7
43-3

22
O
0.4
2.8
8-7

>IOO

> 45
3-5
o
o

4.85

5-5

10.2

5-5
4.0

8
0.4

2.8

8.5

3-5

0.8
4.0

0.75
5.0
10.5

Ductility in cms. at 32 F
Tensile strength in kg. at 1 1 5 F
Tensile strength in kg. at 77 F
Tensile strength in kg. at 32 F

5
15*
16

170
19

Thermal Tests:
Fusing-point, deg. F. (K. and S. method). , .
Fusing-point, deg. F. (R. and B. method). . .
Volatile, 500 F. in 5 hrs., per cent
Flash-point, deg. F

119.5
131-5

0.78
5^5
13.8

142
159
0.50
532
18.5

167
184

I .00

575
23.1

227

595
33-3

121
I4I.5

0. 7 6

520

'33

'54
0.50

555

'43
162

124
142

I 4 6
I6 3

168.5
188

209

220

218
229 . 5

150
167

187
205

"5
132

187

2IO

142
1 60
1.41

487

180
195
o-75
525
36-7

133

6.2

420
17-3

547

515
30.2

535
34-0

545
37-o

563
39-7

530
25.7

552
33-5

528
29.1

56l
38-4

' ' *

22
23

33
34*
34*

Solubility Tests:
Soluble in carbon disulfide
Non-mineral matter insoluble
Mineral matter
Carbenes

99.15
0.50

99.03

0.70

96.45
3.12

91 .02
8.20

97 5
2.15

98.22
1-33

97-95
i. 80

98-93

1.07

98.67
0.9O

98.64

I . IO

98.12
i. 60

86.20
13.48

99-5

O.2

98.3
o.3

99-35

0.48

98.39
1.28

98.7

O.I

98-5

0.2

99-2

1.8
82.5

80.3

5-o
72.3

12.3

61 .0

0.6
76.8

1.82

2.2

'-5

2-5

4.2

5.6

28.2

0.2

0-3
66.7

7 8io

66.6

68.5

O.2
65.0

79.0

Soluble in 88 petroleum naphtha

52.3

45-2

Chemical Tests:
Sulfur

0.95

i-3

o 6

6.4

4.2
1-7
42.9

5.8
1.4
30.3

0.8

2.8

2-5

0.6

Solid paraffins
Saturated hydrocarbons

1.3

1.25
60 7

70.1

2.6

38.5

97 5

Tr.

Tr.
30.6

o.o

35.8

98 o

37-o

0.2
38.0

O. I

42.3

o.o

24.0

0.0

28.3

96.4

0.0

27.5
97.0

O.O

32.1

9 8 tf

O.I

35-2

Sulfonation residue

XX RESIDUAL ASPHALTS 453

pitch ; 109 residual asphalts ; 110 residual asphalt mixed with vegetable
oils; 111 residual asphalt fluxed with fatty-acid pitch; 112 residual as-
phalt in combination with aluminium oleate or stearate; 118 sludge
asphalt; 114 wurtzilite asphalt; 115 gilsonite mixed with vegetable
oils; 116 gilsonite fluxed with fatty-acid pitch; 117 asphalts fluxed with
resins; 118 mixture of asphalt, rosin, rubber and vegetable oil; 119
boiling an aqueous dispersion of asphalt with sulfur/ 20

In place of sulfur alone, the use of the following agents has
been proposed for vulcanizing asphalts and mixtures containing the
same : mixture of sulfur and FeS ; 121 mixture of sulfur and SO 2 with
a catalyst (e. g., a sulfide or oxide of P, As, Sb, Sn, Mo, V, or
W); 122 sulfur and lead peroxide; 123 sulfur and calcium oxy-
chloride; 124 sulfur and sulfuric acid; 125 sulfuric acid alone; 126 spent
iron oxide (containing sulfur) obtained as a by-product in desulfur-
izing coal-gas; 127 antimony sulfide, with or without sulfur; 128 sulfur
in the presence of chlorine; 129 sulfur dichloride ; 130 sulfurylchloride
or pyrosulfurylchloride ; 131 chlorine in the presence of a u chlorine
carrier" (e. g. hexachlor ethane) ; 132 cyanide residues; 183 etc.

RESIDUAL ASPHALTS

As stated previously, these are derived from the steam distilla-
tion of semi-asphaltic or asphaltic petroleums. 134 Non-asphaltic
petroleums are unsuitable for manufacturing residual asphalts,
although processes have been devised based upon their use. 135
The distillation is continued until the residual asphalt reaches
the desired "grade." The temperature of the residue in the still is
carefully observed, and under no circumstances allowed to exceed
750 to 800 F,, otherwise excessive decomposition and cracking of
the hydrocarbons will take place, and result in the production of an
inferior product 136 This is especially liable to be the case if a resi-
dual asphalt of hard consistency and high fusing-point is to be pro-
duced. Mexican petroleums are more susceptible to overheating,
and great care must be taken not to allo'w the residue in the still to
exceed a temperature of 575 to 625 F, The distillation must not
proceed too rapidly, otherwise a certain amount of cracking will
take place, and the asphalt will have too low a flash-point and con-
tain a certain amount of free carbon* In the early days of the

454 PETROLEUM ASPHALTS XX

industry, the residual asphalts were carelessly manufactured, with-
out suitable temperature control, and as a result they soon fell into
disrepute. At the present time, residual asphalts are being mar-
keted of excellent quality, including products fusing as high as
225 F M with a hardness in the neighborhood of 100 on the con-
sistometer scale (Test 9^), but this is due solely to the better
methods of control. Other things being equal, it is not as easy to
produce a residual asphalt as a blown product of a given high
fusing-point.

A process 137 for removing undesirable constituents of a paraf-
fin- or vaseline-like character from residual asphalts (12 to 24
Baume) derived from a mixed-base petroleum, consists in intro-
ducing large quantities of low-pressure steam superheated to 600 to
700 F., through a charge of the asphalt heated in a still to 450 to
700 F., or by distilling the asphalt under vacuum. 138 Any free
carbon may be removed from the topped petroleum or pressure tar
or residual oil prior to the final distillation, by precipitation, 139 or by
centrifuging, 140 or by acid-treatment. 141 The temperature may be
suitably controlled during the distillation process by supplying heat
through the medium of a highly-heated mass of so-called "heat-
carrier" (e. g. asphalt, fused metallic salts, molten lead or tin,

etc.). 142

Carelessly prepared residual asphalts may be detected by:

1 i ) Lack of homogeneity (Test 2 ) . This may be due either to
over-heating or because the distillation has been continued too far.

(2) The surface of the material assuming a "greasy" appear-
ance on aging. This is due to the use of crudes containing too large
a proportion of paraffin- or vaseline-hydrocarbons, which have not
been removed during the distillation process.

(3) The presence of too large a percentage of volatile matter
(Test 1 6) or too low a flash-point (Test 17), due to the distillation
not having been carried far enough, or at a temperature sufficiently
high to remove the low boiling-point constituents.

(4) A large percentage of non-mineral matter insoluble in car-
bon disulfide (Test 21). This is due either to overheating or to
the distillation having been carried too far. Carefully prepared
residual asphalts should not contain more than 5 per cent

(5) The presence of carbenes (Test 22), which are produced
by overheating. Carefully prepared residual asphalts should not
contain more than 2 per cenLf

XX RESIDUAL ASPHALTS 455

Residual asphalts made from semi-asphaltic petroleum are not
as susceptible to overheating as those derived from purely asphaltic
petroleum. In both cases the percentage of asphalt recovered in the
distillation process is greater than that contained in the original
petroleum, due to the fact that the heavy lubricating oils are polym-
erized or condensed under the influence of heat into substances re-
sembling asphalt. In a purely asphaltic petroleum, the quantity of
residual asphalt formed during the distillation process is propor-
tionately less than in the case of mixed-base petroleum, but the
residual asphalt in the former case will not show a greasy surface on
aging, no matter how carelessly it may have been distilled.

The effect of continued steam-distillation on the fusing-point,
specific gravity, specific viscosity, float test, penetration, fixed car-
bon and percentage insoluble in 88 petroleum naphtha, for Mexi-
can, Californian and Texas residual asphalts has been described by
B. A. Anderton. 143

Residual asphalts in general comply with the following charac-
teristics :

(Test i) Color in mass Black

(Test 2) Homogeneity Variable

(Test 3) Appearance surface aged indoors i week. Variable

(Test 4) Fracture Conchoidal in the case of

hard residual asphalts

(Test 5) Lustre Variable

(Test 6) Streak on porcelain Black

(Test 7) Specific gravity at 77 F i .00-1 . 17

(Test 9^) Penetration at 77 F 150-0

(Test 9*:) Consistency at 77 F 5-100

(Test 9<J) Susceptibility index 40-60

(Test 10) Ductility at 77 F Variable

(Test 1 1) Tensile strength at 77 F o. 5-10.0

(Test 150) Fusing-point (K. and S. method) 80-225 F.

(Test 15^) Fusing-point (R. and B. method) 100-250 F.

(Test 16) Volatile matter Variable

(Test 17) Flash-point 400-600 F.

(Test 18) Burning-point 450-700 F.

(Test 19) Fixed carbon 5- 40 per cent

(Test 21) Soluble in carbon disulfide 85-100 per cent

Non-mineral matter insoluble o- 15 per cent

Mineral matter o- i per cent

(Test 22) Carbenes o- 30 per cent

(Test 23) Solubility in 88 petroleum naphtha 25- 85 per cent

(Test 28) Sulfur Tr - 10 per cent

(Test 29) Nitrogen Tr.- i .o per cent

(Test 30) Oxygen o- 2j per cent

(Test 32) Naphthalene None

(Test 33) Solid paraffins o- 10 per cent

456 PETROLEUM ASPHALTS XX

(Test 340) Saturated hydrocarbons 25- 75 per cent

(Test 34^) Suifonation residue 90-100 per cent

(Test 37*) Saponifiable constituents o- 2 per cent

(Test 39) Diazo reaction No

(Test 40) Anthraquinone reaction . . . . No

Residual asphalts are characterized by the following features:

(1} Their comparatively high specific gravity, serving to dis-
tinguish them from blown asphalts.

(2) Their greater hardness or consistency at 77 F. for a given
fusing-point, which also distinguishes them from blown asphalts.

(3) The greater tensile strength at 77 F. for a given fusing-
point, which similarly distinguishes them from blown asphalts.

(4) Their lower fusing-point serves to distinguish them from
the asphaltites.

(5) The susceptibility index is very much higher than blown
asphalts. In the case of residual asphalts the susceptibility index is
greater than 40, whereas with blown asphalts it is always less
than 40.

( 6 ) The volatile matter, which for a given fusing-point is lower
than that contained in the crude native asphalts.

(7) The flash-point, which for a given fusing-point is higher
than that of the crude native asphalts.

(8) The fixed carbon, which for a given fusing-point is greater
than that of blown asphalts.

(9) The mineral matter, which runs well within i per cent and
serves to distinguish residual asphalts from most of the native
asphalts,

(10) Carbenes when present in percentages in excess of 5,
serve to distinguish them from native asphalts.

( 1 1 ) Solid paraffins when present serve to distinguish residual
asphalts from native asphalts, although this test is not infallible, for
as pointed out previously, there are certain residual asphalts which
do not contain paraffin (i. e., obtained from asphaltic petroleums)
and conversely, many native asphalts yield small percentages of
paraffins upon being destructively distilled.

(12) The saturated hydrocarbons will exceed 25 per cent in the
case of residual and blown asphalts, whereas they will be less than
25 per cent in the cases of native asphalts. 144 With asphaltites the
saturated hydrocarbons amount to less than 10 per cent.

(13)^ A greater percentage of sulfonation residue is derived
from residual and blown asphalts than from the various pitches.

(14) A negative diazo reaction, which distinguishes residual
asphalts from pitches derived from wood, peat, lignite, coal, shale
and bones.

XX RESIDUAL JSPHJLTS 457

(15) The absence of the anthraquinone reaction, which dis-
tinguishes residual asphalts from the various pitches derived from
coal.

(16) By the percentage of free asphaltous acids (Test 380)
which run below 2 per cent in residual and blown petroleum as-
phalts and above 2 per cent in the native asphalts. Similarly, the
acid value (Test 370) of residual asphalts is usually less than i,
whereas in the case of native asphalts it is higher than 2 and may
run as high as 15. Marcusson 145 reports that the saponification
value (Test 37^) of residual asphalts is usually less than 15, and
in the case of native asphalts is greater than 25, and may run as
high as 36.5.

(17) In the case of natural asphalts, the "oily constituents"
(Test 38e?) are fluid at 20 C, whereas in the case of petroleum
asphalts (blown or residual) they are non-fluid, having the consist-
ency of vaseline.

There has been much discussion whether or not it is possible to
distinguish between petroleum asphalts and native asphalts. 146 Vari-
ous methods have been proposed for the purpose, but the only ones
which seem to give dependable results are the percentages of satu-
rated hydrocarbons (Test 340), free asphaltous acids (Test 380),
acid value (Test 37*0) and the saponification value (Test 37^0,
referred to in items (12) and (16) above.

At the present time it is impossible to distinguish blown asphalts
from combinations of asphaltites with residual oils or soft residual
asphalts, since their respective properties are very much alike.

Residual asphalts obtained from California petroleum are cus-
tomarily designated by letters to differentiate the different grades.
The so-called "A" grade is extremely hard and brittle, grinds to a
non-adherent powder between the teeth, and ranges in penetration
between i and 5 at 77 F. (No. 2 needle, 100 grams, 5 seconds.)
"B" grade is quite hard and brittle, grinds to an adherent powder
between the teeth, and ranges in penetration between 3 and 15 at
77 F. "C" grade chews with difficulty and ranges in penetration
between 10 and 25 at 77 F. U D" grade chews readily without
sticking to the teeth, and ranges in penetration from 25 to 75 at
77 F, "E" grade sticks to the teeth on chewing and shows a pene-
tration greater than 75 at 77 F. "F" and "G" grades are in
reality residual oils of high and low viscosities respectively. When
carefully prepared, "B n grade does not contain more than 2 per

458

PETROLEUM ASPHALTS

cent of non-mineral matter insoluble in carbon disulphide, and the
softer grades correspondingly less. 147

Figure 132 shows the hardness, tensile strength (multiplied by
10) and ductility curves of a typical sample of "D" grade Cali-
fornia residual asphalt fusing at 124 F. (K. and S. method).

Table XLI includes the results obtained by the author, and
Table XLII figures reported by J. Manheimer, 148 on representative
specimens of residual asphalts.

77 a

100
90
80
70
60
50
40
30

too

teeEKO
Hardness

Tensile
~ Strength^

Ductility
O Fusing Point

s
\

- i

\
>

64. &

\
\

7 A

s >

\
\

*fj

s s

>5\

\
\

>*
/

*fr.

"'V

10 ^0 30 40 50 60 70 60 30 100 IK) 12^ 130 140 ISO 160

Temperature, Degrees Fahrenheit

FiG, 132. Physical Characteristics of D-Grade California Asphalt.

The weather-resisting property of residual asphalts varies, de-
pending upon the following circumstances :

1 i ) The crude petroleum from which they were derived. Other
things being equal, asphaltic petroleum produces the most weather-
resisting residues, semi-asphaltic petroleum comes next, and non-
asphaltic petroleum produces residuals having the least weather
resistance.

(2) The care with which the distillation has been performed.
If the residue is badly decomposed or "cracked," as evidenced by
the presence of free carbon or carbenes, its weather-resisting prop-
erties will suffer in proportion.

(3 ) The extent to which the distillation has been carried. Soft
grades of residual asphalt carrying a large percentage of oily con-
stituents (Test 38*) will stand the weather better than those from
which the oily constituents have been removed by driving the dis-
tillation to a point where a hard and brittle residual asphalt remains.

RESIDUAL ASPHALTS

459

w>n N t*o t-cnC
^.vrn^Ok^xnOy)^.?

5 H V) *f N
tOOO O t-. v
H H nvo t^

Q 00 w> O <O O
^OM*oio

H H O M M M

to "* f*5 h- Q O
)HVOOHOOO

8
88

i
I

a
H

K^.0'

-H MNN<

O^OOO
. o v>ir>

m O />

* 06 -

*COO rf oc O
't '^OiOO

o cr> o o o o

_C* rf rf w 5

fO 1000 W M 00 V)00

M M M v> JC

MOOVO\OOOOMCT co O vo t^. "

V <J

<t IO ^- M O O
^1 1000 M O

>. o M <2

M t^. O W> O O 00 <JO >0 N.tO 00 OO
C 00 O H O> O -^VD Oi

' -

O f

- O O>

MHM<Of

HK Q> O HM
or>-O mCTis.

IM^

\OOMi oOOMixOO >000 ooO fi *
't'VOOO O M rt^DOO fOUSOO O

+ HHH O M M M O 1&MHMVOVO

O w

O Ch
> O

*^vo t>. M to *o tooo oo *t 't to 10 o~i <>
H 1000 M O ' >000 M CO tO Q

~f HWCI Ow >ThMMC 'o < M fr

*A "*">

o wnvH

460 PETROLEUM ASPHALTS XX

In general, residual asphalts of the highest quality are inferior
in weather-resisting properties to native asphalts, blown asphalts,
wurtzilite asphalts and fatty-acid pitches, upon comparing respective
products of the same fusing-point and volatility. They are superior,
however, to corresponding sludge asphalts and pitches derived from
rosin, wood, peat, lignite, coal and bones.

SLUDGE ASPHALTS

Sludge asphalts are produced in much smaller quantities than
residual or blown asphalts. They are derived from the purification
of various petroleum distillates by means of sulfuric acid. The
so-called "sludge asphalt" is present in the sulfuric acid sludge,
which on cooling forms a black viscous mass. No asphalts are
obtained from the caustic soda washings in the case of petroleum
refining. The alkali is merely used to neutralize the sulfuric acid
retained mechanically by the oil, thus differing from its action in
the refining of peat and lignite tars.

The acid sludges obtained from the purification of naphtha,
kerosene and lubricating oil are combined and digested with water,
air and steam in a lead-lined receptacle, whereupon the lighter
oily constituents rise to the surface, the acid settles to the bottom,
and the tarry matters form an intermediate layer known as "acid
tar" when it is soft, and "acid coke" when it is solid at ordinary tem-
peratures. The lighter oils are withdrawn and the boiling con-
tinued until all the acid separates. The residuum is then washed
with water, and heated by a spray of superheated steam until it is
converted into sludge asphalt. The further the distillation is con-
tinued, the greater will be the fusing-point and hardness of the
sludge asphalt. The recovered oil is known as the "acid oil distil-
late." The dilute sulfuric acid (specific gravity of 30 to 50 Be.)
is concentrated, first in leaden pans, and finally in an iron still until
it attains a gravity of 66 Be., when it is used over again.

Another process consists in treating the acid sludge with con-
centrated sulfuric acid and live steam until the mass separates into
two layers, the bottom one consisting of concentrated sulfuric acid
which is used over again, and the acid sludge on top. The latter
is washed with hot water, which removes most of the acid, but there
will still remain 3 to 15 per cent of acid mixed with the mass,

XX SLUDGE ASPHALTS 461

which is either heated to 250-350 C. so as to decompose the sul-
f uric acid into SO 2 ; 149 or heated in an autoclave under pressure ; 15
or heated air or steam blown through the melted mass to remove
the SO 2 and SO 3 ; 151 or the free acid may be neutralized with a
residue containing naphthenic soaps; 152 or else neutralized by add-
ing slaked lime or limestone. 153 Other methods of treating acid
sludges consist in heating to not exceeding 250 C. with an equal
weight of residual asphalt under agitation; 154 fluxing with 1-5 per
cent of light gas-oil, emulsifying with water under agitation, break-
ing the emulsion by heating, treating the separated asphalt with
CaO to neutralize all traces of acid, and finally distilling under
vacuum to the desired consistency. 155

The process shown diagrammatically in Table XLIII represents
a method of treating acid sludges derived from heavy hydrocarbon
distillates, such as lubricating oils. 156

Acid sludges may be precipitated by salts of alkaline earths or
of metals (e.g., copper or zinc), and after dehydration may be used
for impregnating fabrics which are exposed continuously to mois-
ture, preserving them from decay. 157

Sludge asphalts test as follows :

(Test i) Color in mass Black

(Test la) Homogeneity to the eye at room temperature. Uniform

(Test 2) Homogeneity under microscope Variable

(Test 3) Appearance surface aged indoors one week. ... Bright

(Test 4) Fracture Conchoidal

(Test 5) Lustre Bright

(Test 6) Streak on porcelain Black

(Test 7) Specific gravity at 77 F 1 .05-1 . 20

(Test 9^) Penetration at 77 F 1 50-0

(Test 9f) Consistency at 77 F 5~ J oo

(Test 9</) Susceptibility index ,..,..., 40-60

(Test 10) Ductility at 77 F o

(Test i$a) Fusing-point (K. and S. method) 80-225 F.

(Test 15^) Fusing-point (R. and B. method) 100-250 F.

(Test 1 6) Volatile matter 500 F. in 5 hours 2- 20 per cent

(Test ija) Flash-point 300-500 F.

(Test 19) Fixed carbon 5- 30 per cent

(Test 21 ) Solubility in carbon disulfide 95-100 per cent

Non-mineral matter insoluble , . o- 5 per cent

Mineral matter (See NOTE) o- i per cent

(Test 22) Carbenes 0-15 per cent

(Test 23) Solubility in 88 petroleum naphtha 6o~ 95 per cent

(Test 28) Sulfur 5- 10 per cent

(Test 30) Oxygen 3- 7 per cent

(Test 33) Solid paraffins o- } per cent

462 PETROLEUM ASPHALTS XX

(Test 340) Saturated hydrocarbons Less than 10 per cent

(Test 34^) Sulfonation residue. 80- 95 per cent

(Test 37^) Saponifiable constituents o- 2 per cent

(Test 380) Free asphaltous acids Less than 2 per cent

(Test 38^) Asphaltous-acid anhydrides , Less than 2$ percent

(Test 39) Diazo reaction No

(Test 40) Anthraquinone reaction No

NOTE. Sludge asphalts all carry traces of lead, derived from the leaden vessels in which they are produced,
which is carried into solution by the sulfuric acid. The presence of lead will serve to identify sludge asphalts, and
differentiate them from all other asphaltic substances. The author's investigations revealed lead varying in
amounts from 0.05 to 0.25 per cent.

Sludge asphalts are characterized by the following features :

1 i ) Their intense black streak.

(2) Their high susceptibility index, which distinguishes them
from blown asphalts.

(3) The high percentage of sulfur.

(4) The high percentage of oxygen, which distinguishes them
from all other forms of asphalt and constitutes one of the most
dependable tests for identifying sludge asphalts.

(5) The very small percentage of paraffin, which distinguishes
them from residual asphalts obtained from mixed-base petroleum.

(6) The extremely small percentage of saturated hydrocar-
bons, which serves to differentiate sludge asphalts from all other
asphaltic products.

(7) The comparatively large percentage of sulfonation resi-
due, which distinguishes them from pitches.

(8) The negative diazo and anthraquinone reactions, which
distinguish them from pitches derived from wood, peat, lignite,
coal, shales and bones.

(9) The large solubility of the harder grades in 88 naphtha,
which distinguishes them from residual asphalts of the same hard-
ness and fusing-point.

Julius Marcusson 158 states that sludge asphalts may be recog-
nized by the presence of sulfo-oxonium compounds, which on treat-
ment with 88 petroleum naphtha will separate in the same manner
as asphaltenes. They may be distinguished from the latter, how-
ever, by dissolving in pyridine and adding water. Asphaltenes will
separate out, but oxonium compounds will remain in solution. They
may be precipitated by adding mineral acids, ferric chloride, silver
nitrate, etc. They are not affected by alkalies, but are decomposed
by hydrochloric acid with the separation of sulfuric acid. A speci-
men of sludge asphalt examined by Julius Marcusson was found to
contain 1 7 per cent oxonium derivatives*

SLUDGE ASPHALTS

463

, ^ j.tt

^53 5>

rsi

... rt 6

111

^ S v

|2|

Si
Jjjj-

till

UT3 8 O

*s! i "3

M w o -*

>a bl*l

-fl

d-liJ1

II
'1-

404

PETROLEUM ASPHALTS

Attempts have been made to blow sludge asphalts, either with
air alone or by blowing in the presence of finely ground CaO. 159
However, the blowing process serves largely to harden the sludge
asphalt and increase its brittleness, unless it has first been fluxed
with vegetable oils. 160 Heating with NaClO 3 converts sludge as-
phalts into resinous products suitable for making molded articles. 161
Sludge asphalts flux completely with gas-works coal tar, with which
it may be distilled. 162

Typical samples of sludge asphalt examined by the author gave
the results included in Table XLIV.

TABLE XLIV
CHARACTERISTICS OF TYPICAL SLUDGE ASPHALTS

No,

Test

From Various Sources, Mostly Mixtures

aa
2b
3
4
5
6
7

Physical Characteristics:
Homogeneity to eye at 77 F . .

Homo.
Homo.
Bright

Homo.
Homo.
Bright
Conch.
Bright
Black
i 068

Homo.
Homo.
Bright
Conch.
Bright
Black
1.090

Homo.
Homo.
Bright
Conch.
Bright
Black
1.076

Homo,
Homo.
Bright
Conch.
Bright
Black
1-155

Homogeneity under microscope .

Appearance surface aged 7 days. , , ,

Fracture

Lustre

Streak

Black

1.057

Black
1.052

Specific gravity at 77 F

96
gc
9<*

10*

Mechanical Tests:
Penetration at 115 F

Too soft
160
25
o.o
3.4
42.2
49.7

7
38
1.5
o o
o 4
10. S

Too soft
95

12
O O

7-1
58 8
59-5
15
82
o

O.I
1.4
4-5

Too soft
28
7

17-5
71 8
61.8
45
18
o
0.35
3 85
30

Too soft
20

19-9
85 4
53 4
3-5
0-75
o

1-3
5 4
8 o

43-1
87.9

> IOO

> 50
o

3-0

7-5
6 o

5
o
o
50-7
95 2

> IOO

> So

o
o
3 S

8 2

5 5

Penetration at 77 F

Penetration at 32 F

Consistency at 115 F

Consistency at 77 F

Consistency at 32 F

Susceptibility index

Ductility in cm. at 115 F

Ductility in cm. at 77 F

Ductility in cm. at 32 F

Tensile strength in kg. at 115 F
Tensile strength in kg. at 77 F

Tensile strength in kg. at 32 F

XS
IS*
16
17<
19

Thermal Tests;
Fusing-point, deg. F. (K. and S. method)
Fusing-point, deg. F.(R. and B. method)
Volatile, 500 F. in 5 hrs., per cent
Flash-point, deg. F.

IOI

3 o

47S
8.8

99
H3

2.2
500
12.3

116
134
7-9
430
16,1

1 60
178
2.5

480

22.0

203
225
4-8

482

30.2

210
230

S.o

486

25.4

Fixed carbon, per cent

22
33

Solubility 1 ests:
Soluble in carbon disulfide

98.98
0.90

0.12
0.0
93-2

99 72
o 20
0.08

0.2

94 o

99-51
o 38

II
2 3

78 7

99.23
0.72
0.05
I O

74.6

99.50

0.40

O.IO
X.2

66.8

97.50

2.43

o 07

13.2
62.2

Non-mineral matter insoluble .........

Mineral matter ........

Carbenes

Soluble in 88 petroleum naphtha

33
34

346

Chemical Tests:
Sulfur

8.7
o.S
9.0
82.1

7.8
o 4
8.9
88.0

5-4

O.2

7.2

7S
0.25

5.5

6.2

o.z
4.8

8.3

O.I

3.9
93-2

Solid paraffins

Saturated hydrocarbons

Sulf onation residue

XX SLUDGE ASPHALTS 405

Sludge asphalts do not withstand the action of the weather as
well as native asphalts, blown asphalts, residual asphalts, wurtziiite
asphalt or fatty-acid pitch, comparing respective products of the
same fusing-point and volatility, or of the same hardness and vola-
tility. They are substantially equal in weather-resistance to the cor-
responding grades of pitch derived from coal and bones, and are su-
perior to those derived from rosin, wood, peat and lignite. In
practice, they are usually fluxed with other forms of petroleum
asphalt, rather than marketed in their pure state.

A product has been marketed in the United States consisting of
a mixture of sludge asphalt and pressure tar, which is decidedly
inferior in weather-resisting properties. In some cases the sludge
asphalt is mixed with other grades of petroleum asphalt, but with
little benefit to the latter. It is claimed that the ductility of residual
as well as blown asphalts at low temperatures may be improved by
adding acid sludge to the topped oil prior to the distilling or blow-
ing operation. 108

CHAPTER XXI
PARAFFIN WAX, WAX TAILINGS AND RESINS

PARAFFIN WAX
The commercial sources of pyrogenous paraffin wax are:

(1) Peat tar;

(2) Lignite tar;

(3) Shale tar;

(4) Paraffin-bearing petroleums.

The peat-distilling industry is comparatively unimportant and
does not form a factor in the production of paraffin. The lignite
industry has only attained commercial importance in Germany, and
the shale industry in Scotland. The treatment of paraffin-bearing
petroleums for the recovery of paraffin is important the world
around. The methods for recovering paraffin wax from lignite tar,
shale tar and petroleum are substantially the same. In the case of
lignite tar, the paraffin wax is obtained from the distillate fractioned
after the crude oil, known, as the "paraffinaceous mass." With
shale tar the paraffin wax is obtained from the distillate known as
"heavy oil," distilling after the "intermediate or gas-oil" With
paraffin-bearing petroleums, the paraffin wax is obtained from the
fraction known as the "paraffin distillate."

For a description of the methods of refining and purifying par-
affin wax, the reader is referred elsewhere.

Paraffin wax, including commercial "refined paraffin wax" and
"refined scale wax" tests as follows:

(Test i) Color in mass Pure white to yellowish

(Test la) Homogeneity to the eye at room temperature. Uniform to slightly crys-
talline

(Test ic) Homogeneity when melted Uniform and transparent

(Test 4) Fracture Conchoidal to hackly

(Test 5) Lustre Dull and "waxy"

(Test 6) Streak White

(Test 7) Specific gravity at 77 F o. 85- 0.95

(Test 9^) Penetration at 77 F 5-50

466

XXI WAX TAIUNGS 467

(Test gc) Consistency at 77 F ij-8o

(Test gd) Susceptibility index > 100

(Test 10) Ductility at 77 F o

(Test 15$) Fusing-point (R. and B. method) 105-160 F.

(Test is/) Fusing-point (Special method) 100-150 F.

(Test 16) Volatile at 325 F. in 5 hours 20-40 per cent

Volatile at 500 F. in 5 hours 33-60 per cent

(Test 170) Flash-point Comparatively low

(Test 18) Burning-point Comparatively low

(Test 19) Fixed carbon o- 2 per cent

(Test 21) Solubility in carbon disulfide 99-100 per cent

Non-mineral matter insoluble Trace

Mineral matter Trace

(Test 22) Carbenes o per cent

(Test 23) Solubility in 88 petroleum naphtha 99-100 per cent

(Test 30) Oxygen Trace

(Test 33) Solid paraffins 95-100 per cent

(Test 340) Saturated hydrocarbons 90- 99 per cent

(Test 34^) Sulfonation residue 95-100 per cent

(Test 37*) Saponifiable constituents o per cent

(Test 39) Diazo reaction No

(Test 40) Anthraquinone reaction No

Three grades of paraffin wax are specified by the U. S. Gov-
ernment, having fusing-points (Test I5/) of 130-132 F., 124
127 F. and 117120 F. respectively. Normal "slack wax" has a
fusing-point of 125 F. Various fusing-points are demanded by
the trade.

Paraffin wax is remarkably resistant to the action of chemicals,
but on exposure to the weather, the oily constituents soon evaporate,
leaving a pulverulent and but slightly coherent mass behind. This
is not due to oxidation, but merely to volatilization of the oils
present in the wax.

Paraffin wax withstands the continuous action of water very
well and finds a ready market for preparing waterproof papers, for
manufacturing candles, for household purposes, in miners' lamps,
manufacture of matches, drinking cups, bottle caps, cartridge con-
tainers, dry cells, wax figures, molds, crayons, etc.

WAX TAILINGS

This product is obtained during the dry distillation of non-
asphaltic or semi-asphaltic petroleum. The residuum left in the
retort at the end of the first distillation is subjected to a second
process of dry distillation, whereupon the wax tailings distils over,
just prior to the formation of coke. Wax tailings is sometimes

468 PARAFFIN WAX, WAX TAILINGS AND RESINS XXI

termed "still wax," although both these names are misnomers, since
it contains only small quantities of paraffin wax. It consists largely
of decomposition products, including chrysene, picene and anthra-
cene, and has a decided yellow color, by which it is recognized
during the process of distillation. Upon cooling it forms a very
viscous semi-liquid to sticky semi-solid of a characteristic light yel-
low to yellowish brown color. It complies with the following tests :

(Test i) Color in mass Yellow to yellowish

brown

(Test 20) Homogeneity to the eye at room temperature Uniform to very

slightly granular

(Test 2#) Homogeneity under microscope Uniform to gritty

(due to the crys-
talline constitu-
ents present)

(Test 3) Appearance surface aged indoors Variable

(Test 5) Lustre Waxy

(Test 6) Streak Pale yellow

(Test 7) Specific gravity at 77 F i .00-1 . 10

(Test 9^) Penetration at 77 F 10-150

(Test 9*) Consistency at 77 F 5-20

(Test gd) Susceptibility index 20-40

(Test 10) Ductility at 77 F Usually quite high

(Test i$a) Fusing-point (K. and S. method) 60-100 F.

(Test 15^) Fusing-point (R. and B. method) 65-110 F.

(Test i6a) Volatile matter at 500 F., 5 hours 5-10 per cent

(Test 170) Flash-point 300-450 F.

(Test 19) Fixed carbon 2-8 per cent

(Test 21) Solubility in carbon disulfide 98-100 per cent

Non-mineral matter insoluble 0-2 per cent

Mineral matter o-Trace

(Test 22) Carbenes o-Trace

(Test 23) Solubility in 88 petroleum naphtha 95-100 per cent

(Test 28) Sulfur o-Trace

(Test 30) Oxygen 0-2 per cent

(Test 32) Naphthalene Absent

(Test 33) Solid paraffins Tr.-5 per cent

(Test 340) Saturated hydrocarbons 4O~?o per cent

(Test 34*) Sulfonation residue 90-100 per cent

(Test 37*) Saponifiable constituents Trace

(Test 39) Diazo reaction No

(Test 40) Anthraquinone reaction Yes

Wax tailings is an exceedingly good flux, and will thoroughly
amalgamate with the various pitches, likewise with the harder as-
phalts and asphaltites, including even grahamite. 1 It forms a better
flux than the residual oils derived from asphaltic petroleum. A
very small percentage will often serve thoroughly to flux materials

XXI WAX TAILINGS 469

which are otherwise incompatible, and at the same time increase
the ductility of the mixture. Certain asphalts, although they may
flux together at high temperatures, will separate partially on cool-
ing, forming a very finely granular condition, which is particularly
noticeable when the surface of the mixture is freshly disturbed, or
upon drawing a small pellicle into a thread. The presence of a
small percentage of wax tailings will often prevent this, and it
therefore enjoys a unique position among the fluxes. Large quan-
tities, however, should be avoided, as wax tailings is extremely sus-
ceptible to changes in temperature and lacks weather-proof prop-
erties. The presence of wax tailings will increase the solubility of
asphaltic substances in petroleum distillates, and accordingly be-
comes useful for manufacturing certain types of bituminous paint.
A representative sample of wax tailings tested by the author gave
the following results:

(Test 9$) Penetration at 165 F Too soft

Penetration at 77 F too

Penetration at 32 F 51

(Test 9<:) Consistency at 115 F o.o

Consistency at 77 F 5.9

Consistency at 32 F 22, 9

(Test gd) Susceptibility index 25 . o

(Test io) Ductility at 115 F i . i

Ductility at 77 F 3.9

Ductility at 32 F 13.5

(Test 11) Tensile strength at 115 F o.o

Tensile strength at 77 F 0.5

Tensile strength at 32 F 9.5

(Test i $a) Fusing-point (K. and S. method) 90 F.

(Test 15^) Fusing-point (R. and B. method) 98 F.

(Test 170) Flash-point 382 F.

A process has been proposed for coloring wax tailings for use
as a saturant in the manufacture of saturated fabrics, felt-base floor
coverings, paints, etc., which consists in distilling the wax tailings
with superheated steam to a semi-solid or solid consistency and then
combining with a soluble dye such as rhodamine, malachite green,
etc. ; or else forming a mechanical mixture with a colored mineral
pigment. 2 Wax tailings may also be vulcanized by heating with
sulfur. 3 The production of wax tailings is not large, and hence it
is not of great importance to the asphalt industry.

470 PARAFFIN WAX, WAX TAILINGS AND RESINS XXI

PETROLEUM RESINS

These have been produced by distillation of certain crude petro-
leums (e.g., Miri) which are free from asphaltenes, or by the action
of anhydrous aluminium chloride (about 2 per cent) on an unsat-
urated distillate obtained by cracking at a high temperature and low
pressure, having a specific gravity at 20 C. of 0.840.86 and a
boiling range of 23-180 C. The reaction mixture is treated with
NaOH to precipitate the aluminium from the aluminium chloride
polymer, whereupon the resin remains in solution and is recovered
by distillation under reduced pressure, at as low a temperature as
possible. The resin is a hard, amber-colored product, having a
fusing-point of 230240 F. (R. and B.), which is soluble in prac-
tically all hydrocarbon solvents, but insoluble in methanoi, ethyl
alcohol and acetone. It dissolves readily in drying oils, and has an
acid value between o.i and 2. When a film is baked at 220 F.
for i hour, it becomes insoluble in its original solvents. Petroleum
resins are claimed to accelerate the drying properties of linseed
and china-wood oils. 4

ASPHALTIC RESINS

A process has recently been commercialized for producing light-
colored asphaltic substances falling within the chemical classifica-
tion of "asphaltic resins" (see, Test 38^), by removing the as-
phaltenes in accordance with the following procedure : ( i ) precipi-
tating the asphaltenes with an agent, such as gasoline, pentane, etc. ;

(2) treating with chemicals, such as sulfuric acid or sulfur trioxide,
which converts the asphaltenes into an insoluble modification; and

(3) treating with decolorizing agents, such as fuller's earth or
carbon, with or without diluting agents. An example consists in
dissolving residual asphalt derived from Java petroleum in twice
its weight of light petroleum naphtha, then adding 2 per cent by
weight of sulfuric acid, removing the acid tar and enveloping sub-
stances by settling, adding 3 per cent by weight of bleaching earth,
and finally filtering. The naphtha is thereupon removed from the
filtrate by evaporation and the resulting light-colored asphalt steam-
distilled to the required consistency. 5 Its physical characteristics
are quite similar to wax tailings. It is characterized by a specific

XXI ASPHALTIC RESINS 471

gravity at 77 F. of 1.02-1.04, fusing-point (R. and B.) of 100-
130 F., high ductility, brittleness at low temperatures, great sus-
ceptibility to temperature changes, low viscosity when liquefied, and
high adhesiveness. It may be fluxed with low-grade asphalts to
improve the qualities of the latter. 6 The product has been recom-
mended for use in preparing aqueous dispersions suitable for paints
in combination with colored pigments, for impregnating fabrics, and
for other purposes where the light color will prove an advantage.
Another process consists in precipitating the asphaltenes from a
solution of the asphalt in gasoline or petroleum naphtha, by the
addition of colloidal silicic acid, whereupon the solution is decanted
and evaporated; 7 also a process of distilling pressure tar with steam
under vacuum (with or without the addition of A1C1 3 ) collecting a
distillate having a specific gravity of 1.084-1.126, a fusing-point
(R. and B.) of 93-150 F., and a ductility at 77 F. of over 100
cm,, said product being a substantially solid resin at ordinary tem-
peratures. 8 This product has been recommended for the manufac-
ture of pigmented paints and lacquers. 9

CHAPTER XXII
WURTZILITE ASPHALT

Wurtzilite asphalt or wurtzilite pitch, marketed under the name
of "kapak," is produced by cracking or depolymerizing wurtzilite.
It is similar to the latter in its physical characteristics with the ex-
ception of:

1 i ) The hardness, which is very much reduced.

(2) Its fusibility. Treated wurtzilite is fusible whereas crude
wurtzilite is not.

(3) Its solubility. Treated wurtzilite is readily soluble in car-
bon disulfide, and moderately so in 88 petroleum naphtha, whereas
the crude product is practically insoluble in both.

The process consists in heating the wurtzilite in a closed vessel
or still to a temperature of 500 to 580 F., under more or less
pressure. Vapors are evolved during the process that are con-
densed and returned to the still, and in turn attack the wurtzilite,
first reducing it to a plastic mass, which after heating is converted
into a fusible substance. If the vapor pressure becomes too great,
some is allowed to escape. The process which takes place is vir-
tually a "depolymerization." *

Another process consists in grinding together wurtzilite and gil-
sonite and then heating together for some time at 350 C. until
readily fusible, whereupon the mass is fluxed with petroleum
asphalt. 2

In practice, the wurtzilite is first run through a crusher to break
up any coarse lumps, and then fed into a horizontal cylindrical still
through two charging hoppers, one at either end, provided with
tightly fitting covers which are fastened into place before the fires
are started. The bottom of the still is protected by a fire-brick
arch, and the products of combustion after passing underneath the
arch, are returned in three fire-flues running through the still (one

io in, in diameter and two 6 in.), and thence back again in the space

472

XXII TREATMENT OF WVRTZILITE 473

surrounding the still, above the arch. The vapors generated from
the wurtzilite pass upward through two pipes joined to the top of
the still, near the ends, and connected with a single water-cooled
coil, which condenses the vapors and returns most of the condensate
to the still. Not all the condensate is returned, however, for prac-
tice has demonstrated that the optimum results are obtained if 2 to
5 per cent of the distillate (based on the weight of wu^ilite
charged into the still) is drawn off. This may be used as fuel
under the still.

The longer the wurtzilite is heated in its process of manufacture
the greater will be the quantity of oils produced, which act in the
same manner as a flux, and hence the fusing-point and hardness of
the resultant product will be lower.

It takes six to eight hours to raise the temperature of the charge
to 400 F., then four to six hours to reach the maximum tempera-
ture (580 F.), which is maintained from twenty-four to thirty-six
hours. The contents are then allowed to cool to 450 F., and finally
drawn off through a valve at the bottom.

According to the author's investigations, Nova Scotia albertite is
also amenable to this process, although up to the present time it has
not been thus treated commercially.

The wurtzilite asphalts are marketed under various arbitrary
numbers ranking from "o" to "16," each of which is recommended
for a specific purpose, including the manufacture of paints and var-
nish, insulators, for manufacturing insulated wire, for weather-
proofing conduits and cables, as a filler for mechanical and hard
rubber compounds cured by the press or open steam method, for
coating prepared roofings, for manufacturing carriage drills and
similar compositions applied by the calendar process and cured by
the dry-heat method, etc. Certain of these compounds represent
mixtures of wurtzilite asphalt and gilsonite, with or without the
addition of asphaltic fluxes (e. g., residual oil), and vegetable oils
(e. g., linseed oil, palm oil, etc.).

Wurtzilite asphalt complies in general with the following char-
acteristics :

(Test i) Color in mass Black

(Test la) Homogeneity to the eye at room temperature. Uniform

(Test ib) Homogeneity under microscope Uniform

(Test 3) Appearance surface aged indoors one week. ... Very bright

474

WVR.TZIL1TE ASPHALT

XXII

(Teat 4) Fracture Conchoidal

(Test 5) Lustre Bright

(Test 6) Streak Brown to black

(Test 7) Specific gravity at 77 F i .04-1 .07

(Test gb) Penetration at 115 F 15-25

Penetration at 77 F 5-20

Penetration at 32 F 0-15

(Test 9^) Consistency at 1 1 5 F 10-25

Consistency at 77 F 20-50

Consistency at 32 F 50-120

(Test gd) Susceptibility index 30-40

(Test io) Ductility at 115 F 1-5

Ductility at 77 F o-i

Ductility at 32 F o

(Test H) Tensile strength at 115 F 1-4

Tensile strength at 77 F 5-10

Tensile strength at 32 F 8-15

(Test 15*) Fusing-point (K. and S. method) 150-300 F.

(Test 15^) Fusing-point (R. and B. method) 170-325 F,

(Test i6a) Volatile at 500 F., 5 hours Less than 5 per cent

(Test 170) Flash-point 450-600 F.

(Test 19) Fixed carbon 5-25 per cent

(Test 21) Solubility in carbon disulfide 98-100 per cent

Non-mineral matter insoluble o-J per cent

Mineral matter Tr.-2 per cent

(Test 22) Carbenes 0-2 per cent

(Test 23) Solubility in 88 petroleum naphtha 50-80 per cent

(Test 28) Sulfur 4-6 per cent

(Test 30) Oxygen 0-2 per cent

(Test 33) Solid paraffins o-Trace

(Test 340) Saturated hydrocarbons 5-12 per cent

(Test 34^) Sulfonation residue 90-95 per cent

(Test 37*) Saponifiable constituents Trace

(Test 39) Diazo reaction . . No

(Test 40) Anthraquinone reaction No

Specimens of the unfluxed wurtzilite asphalt examined by the
author tested as follows i

No.o

No. i

No. 6

No. 16

(Test gb) Penetration at 115 F

Penetration at 77 F

Penetration at 32 F

(Test gc) Consistency at 115 F

Consistency at 77 F

Consistency at 32 F

(Test gd) Susceptibility index

(Test i$a) Fusing-point (K. and S, method)

(Test io) Ductility at 1 15 F

Ductility at 77 F

Ductility at 32 F

16
6
o

22.9
45.6

IIO.O

3*-4
269

2
O
O

7
I

18.5

41.8
92.2

33-4

220

3
o

15.0

38.5
80.6

200

3
o
o

7
11.7

71.1

31-2
190

XXII PROPERTIES OF WURTZILITE ASPHALT 475

These figures indicate that the extent of softening and lowering
of the fusing-point is dependent upon the extent to which the proc-
ess of depolymerization has progressed. It is interesting to ob-
serve in this connection that the susceptibility index remains prac-
tically unchanged

Wurtzilite asphalt is characterized by its low specific gravity,
high fusing-point, low susceptibility index, extreme toughness and
rubber-like properties (i. e., resiliency), high-tensile strength, small
percentages of oxygen and non-mineral matter, large percentage of
sulfonation residue, and absence of saponifiable constituents.

It is quite similar in many respects to blown asphalts (particu-
larly in regard to its susceptibility index), but may be differentiated
from these by :

(1) A greater hardness or consistency at 77 F. for any given
fusing-point.

(2) A greater tensile strength for any given fusing-point

(3) Smaller percentages of oxygen.

(4) Smaller percentages of saturated hydrocarbons.

Wurtzilite asphalt is also similar in many respects to the fatty-
acid pitches, especially in its toughness (resilience) and its low sus-
ceptibility index. It is distinguished from these, however, by the
following :

(1) Its solubility in 88 petroleum naphtha, which is smaller
than in the case of fatty-acid pitches.

(2) The presence of sulfur, which is absent in the fatty-acid
pitches.

(3) The smaller percentage of oxygen.

(4) The larger percentage of sulfonation residue.

(5) The absence of saponifiable constituents.

In other respects they are apt to test pretty much alike.

Wurtzilite asphalt shows remarkable weather-resistance and
finds its greatest use in manufacturing asphalt paints, for coating
prepared roofings, 8 and for coating cotton-covered wires for elec-
trical insulation. 4 Its use is limited by the small quantity produced,
and the comparatively high price at which it is marketed.

PART V
MANUFACTURED PRODUCTS AND THEIR USES

CHAPTER XXIII

COMPOUNDING OF BITUMINOUS SUBSTANCES
GENERAL CONSIDERATIONS

One of the most important questions which confronts the bitu-
menologist is that of blending the various substances at his disposal,
to produce mixtures best adapted for the special purposes for which
they are intended. This requires an intimate knowledge of the
nature and behavior of the various materials, and can only be thor-
oughly acquired by years of experience. Two shipments of any
given member of the bituminous family are likely to fluctuate widely
in their physical properties and composition, even when procured
from the identical source. A native bituminous substance emanat-
ing from the same deposit will vary, depending upon the degree of
exposure and amount of metamorphosis. It has been shown that
all native bituminous materials are in a constant state of transition,
depending upon their age and environment. Scarcely any two de-
posits of native asphalt are alike in their properties or chemical
composition. The same applies to petroleum, which varies in dif-
ferent localities and very often in wells side-by-side in the same field.

The pyrogenous bituminous materials also show a marked varia-
tion in their properties, depending upon the raw materials used in
their production and the exact conditions to which they have been
subjected in their process of manufacture, including the tempera-
ture, length of treatment, etc.

Bituminous materials should not therefore be compared to vege-
table and animal fats or oils, which in the case of any one material
runs fairly uniform in composition and physical properties.

The consistency of the available raw bituminous materials is

476

XXIH GENERAL CONSIDERATIONS 477

either fixed and definite, or it is controllable. Each native bitumi-
nous substance has a predetermined consistency in other words, it
is endowed by nature with certain fixed and definite physical prop-
erties, and over which man has no control. On the other hand, the
consistency of pyrogenous bituminous substances, with three excep-
tions (i.e., wax tailings, tars and rosin pitch), is largely controllable,
and depends upon the treatment to which they are subjected in the
course of their production. In the majority of pyrogenous sub-
stances, it is a comparatively easy matter to alter their consistency
at will, by regulating the duration of the process, its temperature,
or some other condition. In the three exceptions noted, the con-
sistency is predetermined, and has no definite bearing upon the
variable factors of the process.

Table XLV will serve to give a general idea whether the hard-
ness and fusibility of the various bituminous substances are definite
or controllable, whether the substances are naturally soft, medium
or hard at room temperature ; also their approximate comparative
volatility, weather-proof properties, and efficiency in fluxing.

In interpreting Table XLV, it should be distinctly noted that
the "Hardness at Room Temperature," "Volatility/' "Weather-
proof Properties" and "Efficiency in Fluxing" are listed in a com-
parative sense, and must not therefore be regarded as a definite
exposition of the characteristics of any single substance, without
taking into consideration the other substances cited.

In addition to the bituminous substances, there are included
three groups of non-bituminous substances commonly used for pur-
poses of blending; viz., rosin, animal and vegetable oils or fats, and
wool grease.

In preparing mixtures of bituminous materials, the following
points should be borne in mind :

( I ) Bituminous materials which give the diazo reaction (Test
39) (containing phenols), should not be mixed with bituminous
substances not giving this reaction. In other words, native asphalts,
asphaltites and pyrogenous asphalts should not be blended with tars
or pitches (excepting fatty-acid pitch), since it has been found by
experience that such mixtures, although they may melt together per-
fectly, are not durable or weatherproof, although such mixtures
have been used successfully for sub-soil waterproofing purposes and
certain types of pavements.

478

COMPOUNDING OF BITUMINOUS SUBSTANCES

XXIII

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XXIII CHARACTERISTICS OF BITUMINOUS SUBSTANCES

479

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480 COMPOUNDING OF BITUMINOUS SUBSTANCES XXIII

(2) Native and pyrogenous waxes will not remain permanently
blended with other bituminous materials, but will crystallize at low
temperatures, gradually separating from solid mixtures on standing.
This manifests itself by the wax "sweating" from the surface. In
certain cases this feature is desirable, since the admixture of a small
percentage of wax imparts wax-like properties to the entire com-
position.

(3) Grahamite does not flux with native or pyrogenous waxes,
residual oils derived from non-asphaltic petroleum, fatty-acid pitch
or wool grease.

(4) If the bituminous material contains a percentage of "non-
mineral matter insoluble in carbon disulfide," the act of fluxing with
other bituminous substances, rosin, animal or vegetable oils and fats
will only dilute this ingredient, without eliminating it. The calcu-
lated proportion will still be present in the mixture.

(5) The percentage of carbenes may be reduced by fluxing or
blending, as the carbenes themselves are fluxed by other bituminous
substances, rosin, animal or vegetable oils and fats.

(6) The thoroughness with which bituminous materials blend
may be ascertained by finding the fusing-point of the components,
ana comparing the calculated fusing-point of the mixture with its
actual fusing-point. If the actual fusing-point is ecjual to, or
greater, than the calculated fusing-point, then the blending has been
thorough. On the other hand, if the actual fusing-point is less than
the calculated fusing-point, then the components do not amalgamate
thoroughly.

(7) The microscopic test may also be used to good advantage
to ascertain the thoroughness with which the components blend. A
separation of particles in the mixture is evidence that perfect amal-
gamation does not occur.

Where the hardness and fusibility of the bituminous substance
are "controllable," it is often a simple matter to continue the dis-
tillation, blowing, depolymerization (in the case of wurtzilite as-
phalt), etc., until a product is obtained having the desired physical
characteristics. Where conditions permit, it is more convenient and
economical to turn out a product of exactly the proper grade, than
to flux or harden it afterwards. It is accordingly customary 1 to
market residual asphalts of exactly the right hardness and fusing-
point for paving purposes, etc. Blown asphalts are similarly mar-
keted in various grades, having different fusing-points (and hard-
nesses), so that the manufacturer may pick out one best adapted to
his particular purpose. Coal tar is likewise distilled to a predeter-

XXIII

BINARY MIXTURES

481

mined extent to obtain pitches suitable for use as such in connection
with waterproofing, roofing work, road purposes or briquette mak-
ing, whichever the case may be.

Binary Mixtures. It is not always possible to use a single bitu-
minous material, since it is sometimes found that the exact charac-
teristics required are lacking, and can only be obtained by blending
together two or more substances in suitable proportions. The sim-
plest mixtures, containing two constituents, are known as "binary
mixtures." In this case it is often possible to predict with a fair
degree of accuracy what the characteristics of the mixture will be.
That this is not always a simple matter is indicated by the following
figures. The same blown asphalt was used in both cases, whereas
the steam-refined asphalts A and B differed slightly: 1

TABLE XLVI

Per Cent of Blown
Asphalt Combined
with:

Penetration
at 7 7F.
(Test ?*)

R. and B. Fu sing-
Point deg. F.
(Test 15^)

Ductility
at 77 F.
(Test loa)

Steam-refined Asphalt "A":

131

130

129

124

126

127

134

57.5

12.5

100

270

i.J

Steam-refined Asphalt "B":

13*

132

129

136

. M3

19.5

151

9.5

173

4.25

100

270

-S

The purpose of preparing a mixture is to soften the substance
and lower its fusing-point, harden the substance and raise its fusing-
point, render the mixture less susceptible to temperature changes,
effect a more perfect union or blending of the constituents, improve
its weatherproof properties, increase the tensile strength, render the

482

COMPOUNDING OF BITUMINOUS SUBSTANCES

XXIII

mixture wax-like, or unctuous to the feel, lessen the tendency to-
wards stickiness, etc.

Softening the Substance and Lowering Its Fusing-point. This
process is ordinarily known as "fluxing." When the bituminous
material, as it occurs naturally or results from a manufacturing
process is too hard in consistency or fuses at too high a temperature,
it is customary to mix it with a softer substance, termed a "flux,"
to impart the necessary characteristics. The fluxes may be classi-
fied in three groups as follows :

GROUP I

For Softening Asphaltic
Materials and Asphaltites

GROUP II
For Softening Pitches

GROUP III
Used Indiscriminately for
Softening Asphaltic Materials,
Asphaltites and Pitches

Soft native asphalt
Residual oils
Pressure tars
Soft blown asphalt
Soft residual asphalt
Soft sludge asphalt

Medium wood tar pitch
Medium peat-and lignite-tar
pitches
Medium water-gas-tar pitch
Medium oil-gas-tar pitch
Medium coal-tar pitch
Medium bone-tar pitch

Wax tailings
Soft and medium fatty-acid
pitches*
Animal and vegetable oils and
fats
Wool grease*

* Not suitable for fluxing grahamite.

The fluxes listed in Group II should not be used for softening
asphaltic materials and asphaltites, or those in Group I for soften-
ing pitches (excepting rosin- and fatty-acid pitches), for reasons al-
ready explained. The fluxes listed in Group III will answer satis-
factorily for softening asphaltic products, asphaltites and pitches,
without injuring their weather-resisting qualities.

Of Group I fluxes: residual oils, soft blown asphalt and soft
residual asphalt are ordinarily used, on account of their weather-
resisting properties, their efficiency in fluxing, the absence of vola-
tile constituents and their comparative cheapness.

Of Group II fluxes : water-gas-tar pitch and oil-gas-tar pitch are
ordinarily used for preparing "cut-back" coal-tar pitches for use
as dust-laying oils, road surfacings, etc.

Of Group III fluxes: animal and vegetable oils or fats are most
generally employed, owing to their abundance and uniformity.
They are only used in special cases (e.g., manufacturing certain
bituminous lacquers, varnishes and japans, rubber substitutes, coat-
ing compositions for high-grade prepared roofings, etc.), in view of
their comparatively high price, although they are without question
the fluxes par excellence ror bituminous materials*

XXIII BINARY MIXTURES 483

Augmenting the Adhesive Properties of the Substance. Bitu-
minous substances may have their adhesiveness enhanced by fluxing
with a small percentage (e.g., o.i to 2 per cent) of the following
materials: an aromatic or aliphatic alcohol (e.g., fusel oil) ; 2 cyclo-
hexanone, CO.Et.C 5 H n , Bu 2 C 2 O 4 , etc.; 3 naphthalene or hydro-
naphthalene dissolved in alcohols or ketones ; 4 naphthenic acids ; 5
solid fatty acids (e.g., stearic), resin acids or oxidized paraffin
wax; 6 polymerized vinyl chloride; 7 crude phenols; 8 "rubber oil"
obtained in the destructive distillation of rubber; 9 etc.

Increasing the Fluidity of the Substance When Melted. An-
other group of materials is of interest in connection with saturants.
They have been termed "introfiers" (i.e., impregnation accelera-
tors), 10 and when added to an impregnating material in relatively
small quantities will jesult in a marked change in its fluidity and
wetting properties towards the material being impregnated, increas-
ing the speed of penetration. This group of materials includes sub-
stances of the type of naphthalene (e.g., naphthalene, naphthols,
naphthylamines, hydronaphthalenes, chloronaphthalenes, etc.); py-
ridine bases (e.g., pyridine, picolines, lutidines, quinoline, quinal-
dine, acridine, or similar compounds); 11 nitrogenous distillation
products (e.g., dipped oil, bone oil, shale oil, etc.); 12 also of the
type of diphenyl (e.g., diphenyl, diphenylmethane, dibenzyl, phenyl
ether, fluorene, etc.) ; also of the type of triphenyl (e.g., triphenyl-
methane, triphenylchloromethane, triphenylphosphate, etc.); like-
wise paracumarone ("cumar") resin; 13 etc.

Effecting a More Perfect Union or Blending of the Constituents.
At times the components of a bituminous mixture do not amalga-
mate thoroughly. This is detected by a lack of homogeneity (Test
2), i.e., by distributing the surface and observing whether it becomes
duller, or else by drawing out a pellet into a thin thread, and noting
whether any dulling occurs. Certain fluxes when combined with the
mixture, often in a small proportion, serve to overcome this ten-
dency, and result in a more complete amalgamation of the compo-
nents. Such fluxes in the approximate order of their efficiency are
as follows:

Rosin Animal or vegetable oils and fats

Rosin pitch Wax tailings

It will be understood that these fluxes do not influence the per-

484 COMPOUNDING OF BITUMINOUS SUBSTANCES XXIII

centage of non-mineral matter insoluble in carbon disulfide (free
carbon), or any dullness due to this constituent.

In general it may be stated that petroleum asphalts and coal-tar
pitch do not readily amalgamate except in restricted proportions. 1 *

Gilsonite has been recommended as an addition to asphalts for
the purpose of "correcting" heterogeneity. 15 Waxy substances (e.g.,
paraffin wax) are better tolerated by some asphalts than by others,
but may be combined in nearly all proportions with gilsonite selects,
and without danger of subsequent separation, which fact is taken
advantage of in the insulated-wire industry.

A greater percentage of natural asphalts (e.g., Trinidad as-
phalt) may be blended with coal tar and coal-tar pitch without
coagulating the free carbon present in the latter, than proves to be
the case with petroleum asphalts. 18

Asphalts having the highest surface-tension flux best with tars, 1T
and homogeneous mixtures are favored through the use of soft tars
and hard asphalts. 18 The addition of the following substances will
promote the fluxing of coal-tar pitches and petroleum asphalts:
rosin or wax tailings; 10 anthracene oil; 20 Dippel's oil or shale oil,
and nitrogenous bases; 21 organic compounds of heavy metals (e.g.,
lead oleate or lead resinate) ; 22 certain forms of colloidal mineral
matter (e.g., A1 2 S1O 3 or A1 2 O 3 ).

Coal-tar pitches will flux in all proportions with vegetable oils
(plain or vulcanized) and fatty-acid pitches, 23 and coke-oven tar
will blend in all proportions with pressure tars derived from pe-
troleum. 24

Mixtures of coal tar and asphalt are favored for road construc-
tion in Europe and Great Britain, it being claimed that such mix-
tures have the following advantages over the use of tar alone:

1) Have increased viscosities at elevated temperatures.

2 ) Are less susceptible to temperature changes.
; Possess greater adhesive qualities.

4) Have greater weather-resistance.

Up to 20 or 25 per cent petroleum asphalt or coal-tar pitch respec-
tively may be incorporated in the mixture and form a homogeneous
composition. If more than 25 per cent asphalt is fluxed with coal-
tar pitch, or conversely, if more than 25 per cent of coal-tar pitch
is fluxed with asphalt, a separation of the constituents will take

XXIII

BINARY MIXTURES

485

place, as may be observed by a visual examination of the material
under the microscope (Test 2&), or sometimes even by the naked
eye (Test ^a].

German practice favors the use of 1 5-30 per cent by weight of
petroleum asphalt (31-35 C. fusing-point by K. and S, method)
and 85-70 per cent by weight of coal-tar pitch. 25

The effect of successive additions of petroleum asphalt to coal
tar generally results in the following changes :

Up to 10 per cent Slight improvement.

15 to 25 per cent Marked improvement.

30 to 50 per cent Segregation and precipitation.

50 to 70 per cent Increased homogeneity.

70 per cent upwards Homogeneous and stable.

In preparing the mixture, the asphalt is added to the tar, both
being maintained at about 120 to 130 C. The mixture is kept well
stirred, while the temperature is gradually increased to 150 C.

In an extreme instance we learn that pulverized oil shale (e.g.,
Colorado oil-shale) will flux with coal-tar pitch or heavy coal-tar
distillates when heated to 300-400 C. until the shale disintegrates
and the "kerogen" dissolves. 26 A similar process has been de-
scribed for fluxing bituminous (i.e., "coking") coal which consists
in first pulverizing the coal and then digesting it in a closed retort
with coke-oven tar, water-gas tar, or the like. 27 The fluxed mix-
ture may be used for impregnating felt, 28 or for preparing molding
compositions. 29

Hardening the Substance, Raising Its Fusing-point and Increas-
ing Its Stability. Where the bituminous substance is too soft for
the purpose intended, it is customary to harden it either by distilla-
tion, 30 or by adding one or more of the following materials :

GROUP I

For Hardening Asphaltic
Materials

GROUP II
For Hardening Pitches

GROUP III
May Be Used Indiscriminately
for Hardening Asphaltic
Materials or Pitches

Hard native asphalt
Asphalti tes
Hard residual asphalt
Hard sludge asphalt
Hard wurtzilite asphalt

Hard wood- tar pitch
Hard peat- and lignite-tar
pitches
Hard water-gas-tar pitch
Hard oil-gas-tar pitch
Hard coal-tar pitch
Hard bone- tar pitch

Rosin pitch
Rosin

Hard fatty-acid pitch
Blowing with air
Combining with sulfur
Fillers, etc.
Dispersions of colloidal solids

486 COMPOUNDING OF BITUMINOUS SUBSTANCES XXIII

Of Group I hardeners, hard native asphalts, hard residual as-
phalts and asphaltites are most -frequently used; and similarly of
the Group II and Group III hardeners, hard coal-tar pitch and
fillers respectively are most generally employed. The fillers may
be of vegetable or mineral origin, and will be discussed in greater
detail later. It is not customary to harden bituminous mixtures by
blowing with air after they are once blended, although this pro-
cedure would increase the hardness and particularly the fusing-
point All bituminous substances may be hardened by heating with
a small percentage of sulfur after the manner of vulcanization in
the rubber industry. 31 This is only used to a limited extent, owing
to the difficulty of controlling the degree of hardening, also because
of the fact that it tends to reduce the ductility of the product.
Other methods for hardening asphalts consist: in heating them with
i per cent concentrated H 2 SO 4 ; 82 heating natural or petroleum as-
phalts with i-io per cent, or pitches with 5 per cent HNO 3 ; 33 treat-
ing pitches (e.g., naphthol pitch) with mineral acid and formalde-
hyde ; * 4 heating asphaltites or asphaltic pyrobitumens under pres-
sure with nascent hydrogen; 35 etc.

Rendering the Mixture Less Susceptible to Temperature
Changes. It is difficult to lay down any definite rules in this con-
nection. In general, it may be stated that the suitable addition of
the following substances will tend to make mixtures more resistant
to temperature changes, viz. :

Asphaltites Fatty-acid pitch Rubber

Blown asphalt Animal or vegetable oils and fats Chlorinated rubber

Wurtzilite asphalt Fillers (mineral and vegetable)

The first three, of course, should only be used in connection with
asphaltic mixtures, whereas the next three are applicable either to
asphaltic mixtures or pitches. Animal or vegetable oils and fats
which have been thickened or "boiled" by heating to a high tem-
perature until they polymerize, are more efficient in this respect
than oils or fats in their crude state. Rubber (vulcanized or unvul-
canized) or chlorinated rubber 36 may be incorporated in asphalts,
coal tars or coal-tar pitches, by: (a) dissolving "crum" rubber in
asphalt flux-oil or low-temperature tar-oils, and removing the latter
by steam-distillation, and thereupon employing the mixture thus ob-

XXIII BINARY MIXTURES 487

tained for cutting back harder asphalts or coal-tar pitches; (b) by
homogenizing tar with latex, or latex treated with sodium nitrite,
and removing the water; (c) by heating asphalt or coal-tar pitch
with a mixture containing equal parts by weight of rubber and
sulfur. Rubber, when thus incorporated without overheating, will
increase the elasticity, hardness and fusing-point of the mixture. If
overheated, the rubber will be decomposed and exerts a harmful
effect on the product. 37 Rubber may be fluxed with coal-tar pitch
in the presence of stearic acid. 88 Other procedures consist in mixing
asphalt, coal-tar pitch with cumar (i.e., paracumarone) resin; 89 or
phenol-aldehyde resin; 40 incorporating an aqueous mixture of
wheat glutin and glycerin and expelling the water under heat; 41
etc.

Increasing the Tensile Strength of the Mixture. For some pur-
poses it is important that a bituminous mixture shall have the maxi-
mum tensile strength, to enable it to withstand the stresses and
strains to which it may be subjected in usage. This is of special
importance in the case of certain forms of bituminous pavements.
Two general methods are used for the purpose, viz. :

1 i ) Incorporating mineral fillers.

(2) Increasing the hardness, by blending with harder bitumi-
nous substances.

The tensile strength of a soft bituminous mixture increases to a
certain point upon being blended with harder bituminous substances,
but these have a tendency to reduce the strength when the mixture
reaches the hard and brittle stage.

Making the Mixture More Weatherproof. This is another
question which cannot be decided by any hard and fixed rules, as it
depends largely upon what materials are present in the mixture, and
how badly it may lack weatherproof qualities. There may be cases
where the bituminous substance is so deficient in weatherproof
properties that it would be impracticable to attempt improving it,
on account of the extremely large proportion of material which
would have to be added to overcome this defect. In general, it
may be stated that the addition of the following products tends
to overcome the non-weatherproof properties of bituminous mix-
tures :

488

COMPOUNDING OF BITUMINOUS SUBSTANCES

XXIII

GROUP I

For Augmenting the Weatherproof Properties
of Asphaltic Materials Only

GROUP II

For Augmenting the Weatherproof Properties
of Pitches as Well as Asphaltic Materials

Asphahites

Certain native asphalts
Certain residual oils
Blown asphalt
Wurtzilite asphalt
Certain fatty-acid pitches

Animal or vegetable oils and fats
Wool grease
Fillers (mineral only)
Dispersions of colloidal solids

Of the products included in Group I, the asphaltites, wurtzilite
asphalt and certain fatty-acid pitches (of the saponifiable type) will
most effectively improve the weather-resisting properties of the mix-
ture, due to the fact that these materials of themselves are highly
weatherproof. Among the asphaltites, grahamite is most weather-
resisting, gilsonite and glance pitch ranging next in efficiency and
being about equal in this respect Wurtzilite asphalt is extremely
weatherproof, and the same also applies to the saponifiable varieties
of fatty-acid pitch. Only certain native asphalts and residual oils
are included in this category, for it is impossible to lay down any
definite rules to differentiate between the non-weatherproof and
weatherproof varieties, since this can only be determined as the
result of experience or by an actual exposure test. The physical and
chemical tests fail to determine definitely whether a native asphalt
or residual oil will display the optimum weather-resistance in actual
service. Certain tests (e.g., large percentages of volatile matter
and non-mineral constituents insoluble in carbon disulfide), may defi-
nitely pronounce the material to be non-weatherproof, but if these,
by chance, prove negative, the court of final appeal is an actual
exposure test under service conditions.

Both fluxes enumerated under Group II are equally efficient
from the standpoint of weather-resistance, although the first named
is superior in its fluxing properties. The use of drying oils com-
bined with metallic oxide driers has also been recommended; 42
also "factice" and cholesterol derivatives; 48 likewise the addition
of a small percentage of wood-tar pitch. 44

Mineral fillers when added in a finely divided state, or in the
form of graded particles, proportioned to show the minimum per-
centage of voids, tend to improve the weather-resistance of all bitu-

XXIII TERTIARY AND COMPLEX MIXTURES 489

minous substances. Those fillers which are impermeable to light
are most efficient in this respect. The same rules apply in this con-
nection as with mineral pigments in linseed oil paints. 45 It is claimed
that the weather-resistance of bituminous substances may be im-
proved by subjecting a warm solution in a solvent to the influence of
ultraviolet light, while ozone is being blown through/ 6

Rendering fFax-like, Unctuous to the Feel, or Lessening the
Tendency towards Stickiness. For certain purposes, it is desirable
to impart the foregoing properties to bituminous mixtures, espe-
cially in manufacturing insulating compounds, rubber substitutes,
coating compositions for papers, etc. The addition of a small per-
centage of the following waxes (usually less than 10-15 per cent)
will serve to accomplish this result:

Ozokerite Montan wax Pyrogenous waxes

These will not amalgamate permanently with bituminous ma-
terials, but will work their way to the surface in time, forming a
thin waxy film which will modify the characteristics of the mixture,
imparting certain of the physical properties of waxes. In the case
of ozokerite and pyrogenous waxes, only a small percentage should
be added, otherwise the separation will be sufficiently great to de-
stroy the integrity of the mixture. Montan wax may be added in
large quantities, as it constitutes a better flux and shows but a slight
tendency towards separation. The stickiness and tackiness of bitu-
minous mixtures may be decreased by incorporating: a mixture of
paraffin wax and phenol; 47 a synthetic resin; 48 resinates, sulfonates,
naphthenates, or linoleates of heavy metals (e.g., Mn, Co, Pb,
etc.). 49

Tertiary and Complex Mixtures. In the case of binary mix-
tures, the characteristics of the blended product may be predicted
with a reasonable degree of certainty, but with tertiary or quater-
nary mixtures this is extremely difficult, and in many cases impos-
sible to do, even by one highly skilled in the art We must bear in
mind that the native asphalts, for example, occur in hundreds of
varieties, each differing in certain respects from the others, or as
one authority on the subject aptly expresses it: "No two deposits
of native asphalt or petroleum on the face of the earth are exactly

400 COMPOUNDING OF BITUMINOUS SUBSTANCES XXIIi

alike." Similarly, blown asphalts, residual asphalts, coal-tar pitches,
etc., are produced in hundreds of grades, depending upon the na-
ture of the crude materials, the temperature to which they have
been subjected, the length of blowing, the duration of the distilla-
tion process, and many other factors. These result in the produc-
tion of a whole series of products from any particular raw material,
varying in fusibility, hardness and other physical and chemical char-
acteristics. Since each class of raw material is available in hundreds
of varieties, it will be apparent that the number of possible combi-
nations in tertiary mixtures is infinite.

In color matching, a given shade may be produced in a dozen
different ways, each starting with totally different colors, and simi-
larly, a given bituminous substance may be exactly duplicated in
physical characteristics (i.e., fusing-point, hardness, ductility, tensile
strength, volatility, etc.), by numerous mixtures, each containing
different combinations of different materials.

The only way to match a given bituminous substance is by the
"cut and try method." This applies with more force when it comes
to tertiary and complex mixtures. To duplicate exactly a complex
bituminous mixture is one of the most difficult and at the same time
one of the most fascinating problems in bitumenology* At the
present stage of the science, a chemical analysis of the material to
be duplicated will tell nothing. It is only an intimate knowledge of
the physical properties of the available bituminous raw materials,
and an inference of their behavior in combinations, that will assist
the expert in synthesizing a mixture having substantially the same
properties as the one to be duplicated.

The problem is made still more complicated by the fact that
although we may apparently succeed in duplicating the physical
properties of a given bituminous mixture, yet there is no way of
telling other than from an actual service test whether or not it will
behave the same on aging or upon exposure to the elements.

Classes of Bituminous Mixtures. Bituminous substances and
their mixtures may be roughly divided into three general classes
based on their physical properties, characterized by being "soft,"
"medium" and "hard" at room temperature. The following table
will show which of the commercial products belong to the respec-
tive classes:

XXIII CLASSES OF BITUMINOUS MIXTURES 491

Soft (liquid) Bituminous Products:

Dust-laying oils.
Binders for road surfacings.

Impregnation for wooden paving blocks, railroad ties, etc.
Tars and oils for the flotation process.

Saturating compounds for prepared roofing, flooring, waterproofing, sheath-
ing and insulating papers, electrical insulating tape, etc.
Waterproofing compounds for Portland-cement mortar and concrete.

Medium (semi-liquid to semi-solid) Bituminous Products:

Binders for bituminous surfacings, bituminous macadam and bituminous

concrete pavements.
Asphaltic cement for sheet asphalt pavements, asphalt-block pavements and

asphalt mastic foot-pavements and floors.
Fillers for wood, brick and stone pavements.
Bituminous expansion joints.
Coatings for prepared roofing, waterproofing, sheathing and insulating

papers.
Adhesive compounds for built-up roofing and waterproofing work; plastic

compounds for repairing roofs, etc.
Pipe-dips and pipe-sealing compounds.
Electrical insulating compounds.
Rubber substitutes and fillers.
Molding compounds.
Bases of bituminous lacquers and cements.

Hard (solid) Bituminous Products:

Certain forms of electrical insulating compounds.

Molding compounds.

Binders for briquettes.

Certain forms of pipe dips.

Bases of varnishes, enamels, japans and certain bituminous lacquers.

Processes of Compounding Bituminous Substances. The types
of apparatus for this purpose fall into two groups, viz. :

1 I ) Open vessels of semi-cylindrical or rectangular form, as
described for dehydrating semi-solid and solid native bituminous
substances.

(2) Closed horizontal cylindrical vessels provided with an agi-
tator in the form of a horizontal shaft carrying short stout blades
or paddles usually set at an angle. This type is mounted on a
masonry foundation over a solid or perforated fire-brick arch, and
the heating effected by burning coal or gas underneath it The
vessel is provided with a manhole at the top, through which the bi-
tuminous substances are charged, and closed with a cap during the
melting process to keep out air and prevent the vapors from igniting.

492 COMPOUNDING OF BITUMINOUS SUBSTANCES XXIII

The first type is used where the bituminous substance is heated
below the flash-point of the constituent flashing at the lowest tem-
perature, and the second where it is necessary or desirable to heat
the mass above the flash-point Since the mass can safely be heated
in the second type to higher temperatures and agitated at a greater
speed without danger of the melted mixture splashing out of the
vessel, it follows that with its use the process of amalgamation will
take place more rapidly.

The dehydrated bituminous substances are introduced into the
melting-tank, preferably in the melted condition, either by gravity or
by means of pumps. Where this is not practical, as with/ high
fusing-point products, such as the asphaltites or native asphalts con-
taining a large percentage of mineral matter, they may be added
cold in the solid state, but in this case it takes longer to melt up
the charge.

The higher the temperature to which the materials are heated,
the more rapidly will the combination take place. It is not neces-
sary, or in fact desirable to raise the heat to the fusing-point of the
ingredients melting at the highest temperature, as these will be dis-
solved by the constituents fusing at lower temperatures, due to their
inherent solvent action combined with mechanical agitation. Thus,
a grahamite fusing at 550 to 575 F. (K. and S. method) will
readily combine with mixed-base or asphaltic residual oils brought
to a temperature of 400 F., particularly if the mixture is kept well
agitated. The grahamite should be introduced in the form of lumps
about the size of hickory nuts, in preference to a fine powder, as the
latter will sinter together if the charge is not agitated, and in addi-
tion will make it difficult to tell when the amalgamation is completed.

Great care should be taken not to overheat the bituminous sub-
stances, as they are all affected either by a prolonged heating at a
moderately high temperature, or upon subjecting to a comparatively
high temperature for a short time. There are no general rules
regarding the behavior of bituminous substances under the influence
of heat. Each will act differently, and resist heat to a greater or
lesser degree. It is rarely safe to raise the temperature higher than
450-500 F, in any of the manufacturing processes involving the
use of bituminous substances. 50 Overheating will manifest itself by:

XXIII METHODS OF BLENDING 493

1 I ) Increasing the specific gravity, viscosity, hardness and con-
sistency, fusing-point, flash-point, burning-point, non-mineral matter
insoluble in carbon disulfide (free carbon), and carbenes.

(2) Decreasing the ductility, volatile matter, solubility in car-
bon disulfide and in 88 petroleum naphtha.

On fluxing native asphalts carrying a substantial percentage of
mineral matter, it is important to keep the mass well agitated, other-
wise the mineral matter will settle out and carbonize against the
bottom of the tank, retarding the ingress of heat, and causing the
bottom plates to burn out rapidly.

When the mixture is to be heated to a high temperature for
other than a comparatively short time, it is inadvisable to effect the
agitation by means of air, as this will increase the fusing-point in
the same manner as in the production of "blown asphalts," Me-
chanical stirrers or dry steam jets are preferable under these
conditions.

Based upon the uses to which they may be put commercially,
bituminous substances may be classified according to their purity
(i.e., freedom from constituents insoluble in carbon disulfide) as
follows :

97-100 per cent purity. . Base of lacquers and varnishes

Saturants for composition roofings and shingles

Impregnation for wood, etc.
67- 97 per cent purity. . Coating compositions for roofings

Adhesive compositions for roofings

Binders for road surfacings

Asphaltic cement for sheet-asphalt pavements
18-67 per cent purity, . . Molding compositions

Bituminous expansion joints

Electrical insulating compounds

Pipe dips and sealing compounds
12- 1 8 per cent purity. . Mastic pavements
9- 1 2 per cent purity. . Sheet-asphalt pavements
5-11 per cent purity. . Bituminous concrete pavements
Less than 5 per cent For enrichment with purer forms of asphalt, etc.

CHAPTER XXIV

BITUMINOUS SUBSTANCES ADMIXED WITH DISCRETE

AGGREGATES

Methods of Incorporating Discrete Aggregates. Since dis-
crete aggregates are incorporated after the bituminous mixture has
been dehydrated and fluxed to the proper consistency, a steam-
heated mixing apparatus of small capacity is best adapted for the
purpose, constructed to mix the charge with great rapidity. Two
forms of steam-jacketed agitators provided with mechanical mixers
are used, viz. :

1 i ) A rectangular tank with a semi-cylindrical steam-jacketed
bottom, commonly provided with two horizontal shafts revolving
in opposite directions, each carrying two sets of short strong blades
or paddles set at different angles, to work the bituminous mixture
from the ends of the vessel towards the centre. The completed
mixture is discharged from the bottom through a power-operated
slide-valve.

( 2 ) A vertical vessel of cylindrical form provided with a steam-
jacketed semi-circular bottom, enclosing a vertical shaft carrying
blades, geared to an auxiliary shaft, offset at one end and provided
with smaller blades which revolve within the larger ones. 1 The
principle of this type is similar to that of a common "egg-beater."
The inner shell is cast from a single piece of metal to avoid danger
of leakage. This form of apparatus is intended only to mix in such
quantities of fillers as will not destroy the fluidity of the mixture or
prevent it discharging by gravity through a spout at the bottom.
When fillers are used, such as silica, earth-colors, or the like, mix-
tures may be prepared containing 60 to 65 per cent of the mineral
constituents.

It has also been proposed to introduce finely divided fillers in
conjunction with a blast of air or steam which is passed through, or
directed against the surface of the melted substance ; 2 or by intro-
ducing the pigment or filler and distilling the mixture to the desired
consistency; s or by mixing the filler with soft asphalt or flux and

494

XXIV

DISCRETE AGGREGATES

495

then incorporating same with hard asphalt, rock asphalt or as-
phaltite; * or by introducing a slurry of the filler and kerosene and

Courtesy of J. H. Day & Co.
FIG. 133. Mixer for Incorporating Large Percentages of Fillers in Asphalt.

PIG. 134. Mixer for Incorporating Coarse Aggregates.

then distilling the mixture ; 5 or by mixing the filler with an aqueous
dispersion of asphalt and then expelling the water by means of

496 DISCRETE AGGREGATES XXIV

heat; 6 etc Various devices have been proposed for drying and
preheating the mineral fillers and aggregates to facilitate mixing
them with the melted bituminous constituents. 7

When it is desired to incorporate light-weight fillers, such as
cork, wood-flour, or vegetable, animal or mineral fibers, a type of
mixer may be used similar to the foregoing But mounted on trun-
nions, so that after the mixing is complete, the entire apparatus may
be tipped bodily, and the contents hoed over the rim while the mass
is hot in a type of apparatus as illustrated in Fig. 133. For incor-
porating heavier or coarser form of aggregate, such as used in
paving mixtures, a form of batch-mixer, known as a twin-plug mill
is used as illustrated in Fig. 134.

The following constitute the more important types of discrete
aggregates which have been proposed for use in conjunction with
bituminous substances:

(A) COLLOIDAL PARTICLES
I. ADMIXED MECHANICALLY:

(a) Inorganic. The following agents may be incorporated in
the dry state with the melted bituminous substance by mechanical
agitation: colloidal clay; 9 slaked lime or lime sludge (CaOH 2 ); 10
whiting; 11 Ca(OH) 2 and glauber's salt (Na 2 SO 4 ); 12 chalk and
alum; 13 limestone derived from fresh-water springs; 14 limestone
mixed with the melted substance under vacuum; 15 magnesium or
barium carbonate; 16 lime soaps (e.g., calcium oleate); 1 ' 7 calcium
cyanamide; 18 lampblack or the like added to asphaltic petroleum
prior to its distillation. 19 The following substances in the form of
an aqueous suspension, may be incorporated with the melted bitu-
minous substance, and the water then evaporated: clay; 20 powdered
limestone or magnesium carbonate ; 2X calcium or magnesium hy-
droxide, calcium sulfate or iron hydroxide; 22 magnesium oxide,
aluminium oxide, iron oxide, or silicates of magnesium and alumin-
ium; 23 zinc oxide with acetic acid; 24 etc. In the foregoing con-
nection, it has been found that bituminous mixtures consisting partly
of aromatic hydrocarbons (e.g., coal-tar creosote) and partly of
paraffins (e.g., semi-asphaltic residual asphalts) act as the best dis-
persoids, and moreover, the use of all aromatic or all paraffin hy-
drocarbons will not effect a satisfactory dispersion.

() Organic, Mixing with soaps (e.g., sodium stearate) ;
or aluminium soap; 26 mixing a hard bituminous substance (e.g.,
hard coal-tar pitch or peat) with a soft bituminous substance (e.g.,

XXIV FILLERS (POWDERS) INCLUDING PIGMENTS 497

coal tar) in the presence of a synthetic resin, by means of a colloid
mill; 27 etc.

2. LIBERATED U IN SITU" :

(a) Inorganic. Treating the melted bituminous substance with
metallic salts, which under the influence of heat break up into dis-
persions and either polymerize the bituminous substance, or in some
instances combine chemically with same, as manifested by an in-
crease in fusing-point, tensile strength, elasticity, ductility and re-
sistance to fracture. The substances recommended for this purpose
include: sulfates or selcnates (e.g., ammonium, copper, iron, chro-
mium, manganese, aluminium, sodium, potassium, rubidium, caesium,
thallium, etc.) ; 2S a mixture of copper sulfate and colloidal clay; 29
metallic chlorides (e.g., zinc, aluminium, tin, copper, cobalt, iron,
magnesium, titanium, arsenic, antimony and bismuth the first
three giving the best results); 30 metallic oxides and peroxides
(e.g., Fe 2 O 3 , PbO, MnO 2 , Ni 2 O 3 , SnO 2 , ZnO, TiO 2 , Cep 2 , Cr 2 O 3 ,
Pb 2 O 3 , CuO, BaO 2 , etc.) ; 81 borax and borates; 32 metallic acetates
(e.g., aluminium, zinc, mercury or sodium); 33 metallic tartrates
(e.g., potassium); 34 phosphoric acid; 35 a mixture of boracic and
oxalic acids; 36 metallic nitrates; etc.

(/3) Organic. Decided rubber-like properties may be imparted
to bituminous substances, and their fusing-point materially increased,
or if desired they may be rendered quite infusible so that they can-
not be melted without carbonizing, by incorporating the following
mixtures with the melted bituminous substance : casein dissolved in
a sulfonated oil, followed by adding formaldehyde ; 8 * animal glue
dissolved in gas-oil; S8 "wrack" dissolved in creosote oil; 89 glycerin-
gelatine composition in conjunction with camphor and sulfur ; 40 a
vegetable phosphatide (i.e., vegetable albumin, such as lecithin) ; 41
etc.

(B) FILLERS (POWDERS), INCLUDING PIGMENTS
(a) Inorganic

i. Oxides:

(a) Silica (SiO 2 ) in its various forms, including: meta-colloidal
silica (e.g., tripoli, trass, volcanic ash, etc.), also hydrated silica
(e.g., geyserite) ; 42 infusorial earth (diatomaceous earth or "Kiesel-
guhr"); 43 powdered silica; 44 powdered sandstone; 45 fine sand; 46
waste sand (e.g., from glass works, foundry cores, sandblasting
operations, etc.). 41

(b) Calcium and magnesium oxides (CaO and MgO), in-

498 DISCRETE AGGREGATES XXIV

eluding: powdered burnt lime; 48 spent lime sludge (e.g., refuse
from sugar-refining operations); 49 magnesia oxide; 60 etc.

2. Silicates:

There are almost infinite varieties of silicates that have been
suggested from time to time for use as fillers, including: kaolin or
clay; 52 fuller's earth (including spent fuller's earth obtained as a
by-product in refining oils); 68 powdered slate; 54 powdered shale,
marl or loam; 55 powdered lava; 56 powdered pumice (pumicite) or
rottenstone ; 57 sillimanite (2CaO.B 2 O 3 .2SiO 2 ) ; 5S aluminium silicate
or Ca.Na.Al.SiO 3 ; 59 Portland cement; 60 calcareous sandstone; 61
loess; 62 talc or soapstone; 03 asbestos sand, floats and asbestine; 64
microasbestos ; 65 mica fines; 66 sea-water mud; 67 soil or earthy
matter; 6S etc.

3. Carbonates:

In this group there may .be mentioned: limestone, chalk or
marble dust; 69 crushed sea shells; 70 powdered bones; 71 tufa
(tuff); 72 magnesium carbonate; 78 also zinc carbonate. 74

4. Sulfates:

Principally: gypsum (plastcr-of-paris or u terra alba") 76 and
barium sulfate (blanc fixe). 76

5. Phosphates:

Including: calcium phosphate ("Brewster dust"). 7T

6. Miscellaneous Rock Products :

This group includes: stone powder ("flour") and dust recov-
ered from crushing operations by air flotation; 78 also electrically
precipitated stone-dusts. 79

7. Pyrogenous Products:

In this we find reference to: ground cinders (coal ashes); 80
"fly ash n (recovered from pulverized-coal furnaces) ; 81 powdered
slag; 82 and brickdust, 83

8. Black Pigments:

These include : graphite ; 84 graphitic slate ; 85 and copper slag
(hydrated ferrous silicate). 86

XXIV GRANULAR MATTER 499

9. Colored Pigments:

Heat-resisting mineral pigments are generally used, including:
strong red iron-oxide; 8T micaceous iron-oxide (hematite) ; 88 yellow
ochre; 89 cadmium yellow; green oxide of chromium; ultramarine
blue; cobalt blue; titanium oxide; sublimed white lead; lithopone; 90
metallic bronzes (e.g., copper, brass, aluminium, iron, etc.); 91 and
mixtures of the foregoing.

(3) Organic

1 . Vegetable Products :

Including: starch; 92 dust recovered in milling grain; 98 sac-
charine matter; w beet-sugar residues (calcium pectates and calcium
carbonate) ; 95 powdered cork; 96 manure; 97 etc.

2. Black Pigments :

Under this sub-division we find : ground peat, lignite or cannel
coal; 98 ground oil shales; 99 powdered coal ("culm"); 100 pulver-
ized natural rock asphalts; 101 ground coal-tar pitch; 102 lamp-
black; 103 carbon black and bone black; powdered charcoal; 104 pow-
dered coke (coke breeze) ; 105 etc.

In this group are included: asbestos; 106 glass wool; 107 slag
wool ; 108 rock or mineral wool. 109

(3) Organic

Including: ground or shredded wood (wood wool, wood flour,
or cellulose wool), saw-dust, wood shavings, etc.; 110 shredded
rag or paper fibers ; U1 cotton linters, cotton flock or cottonseed
hulls; 112 straw (raw or cooked) ; 113 flax, ramie, hemp or sisal; 114
wheat bran; 115 rice husks and hulls; 116 corn stalks and sugar-cane
fibers; 117 cfocoanut fibers; 118 ground tanbark; 119 shoddy and wool
waste; hair; 120 ground leather; 121 ground peat; 122 ground roofing
scrap and waste; 128 etc. See also "Premolded Expansion Joints,"
"Fibrated Bituminous Compositions" and "Felt-Making Fibers."

(D) GRANULAR MATTER
(a) Inorganic

Include various groups of "Fillers" given under sections B--i
to B-a-7 inclusive, in the granular state ; likewise any of the "Inor-
ganic Surfacings Uncolored Granules" for prepared sheet roofings.

(3) Organic

Include corresponding products referred to under "Premolded
Expansion Joints" and "Bituminated Cork Mixtures."

500

DISCRETE AGGREGATES

XXIV

(E) COARSE MINERAL AGGREGATES

1. Crushed Rock, Stone, Gravel or Slag. See "Mineral Ag-
gregates*' under Paving Materials.

2. Graded Aggregates.

(F) COMBINATIONS OF THE FOREGOING

The effect of mineral fillers (Type B-a-j) on the physical char-
acteristics 124 is shown in Table XLVII, based on the mixture of a

TABLE XLVII

Soft residual asphalt (from Mexican oil)
Precipitated calcium carbonate

100%
o%

85%
15%

?o%
30%

55%
45%

40%
60%

(Test 9^) Penetration at 1 1 5 F ...

Too soft

i6<

Penetration at 77 F

185

1-7 <;

Penetration at 32 F

(Test 9*r) Consistency at 115 F

o o

O.O

o o

1 I

Consistency at 77 F

1. 1

4.6

6.5

11. Q

Consistency at 32 F

18.4

22.2

24 I

IO 4

(Test 9<^) Susceptibility index

19.8

22.6

10 C

14. <

(Test io<) Ductility at 1 15 F

14.0

11, o

IO.O

2. C

Ductility at 77 F , . ...

4O O

11 O

11. O

o 6

Ductility at 32 F

2.7

2.6

o.S

o. <

(Test n) Tensile strength at 115 F

o.o

O.O

.0.0

O. 1

Tensile strength at 77 F

0.4

I . I

i .7

2 4

Tensile strength at 32 F

c. c

7. 5

9 5

n.o

(Test 15^) Fusing-point (K. and S. method)

91 F.

98 F.

106 F.

161 F.

(Test 15^) Fusing-point (R. and B. method)

iioF.

ii5F.

124 F.

i88F.

Medium residual asphalt (from Mexican oil)
Precipitated calcium carbonate

100%
0%

85%

IC%

?o%

10%

55%
45%

40%
60%

(Test 9^) Penetration at 1 1 5 F

240

170

Penetration at 77 F

Penetration at 32 F

(Test 9^) Consistency at 1 1 5 F

2. 1

2 7

r 75

11.6

17. 1

Consistency at 77 F

IO O

12.4

17. 6c

26.2

36.6

Consistency at 32 F

47. 1

<I .Q

?4. 1

66. Q

80.4

(Test 9*/) Susceptibility index

38 2

1Q-7

1C.

28.0

26.2

(Test io) Ductility at 115 F

27.O

22.

II. O

0.8

Ductility at 77 F

38.0

IJ.O

I.I

0.25

Ductility "at 32 F

O.O

O.2

O. I

O.O

(Test n ) Tensile strength at 1 1 5 F

o.o

O.2

0.8

1.8

Tensile strength at 77 F ...

i 6

2 2

A i

6.7

Tensile strength at 32 F.

9 6

IJ..O

20 <

27. 2

(Test 15*) Fusing-point (K. and S. method) .
(Test 15^) Fusing-point (R. and B. method).

u8F.
136 F.

124 F.
145 R

135 F.
158 F.

190 F.
216 F.

242 F.
269 F.

* Does not Sow when heated.

XXIV EFFECT OF MINERAL FILLERS 501

straight run residual Mexican asphalt with o, 15, 30, 45 and 60
per cent of precipitated calcium carbonate.

It will be noted that the fusing-point, hardness, and tensile
strength increase, whereas the susceptibility index and ductility de-
crease in proportion to the quantity of filler added. When the per-
centage of filler is sufficient to destroy the fluidity of the mixture,
as in the case of the surface course of sheet asphalt pavements
(where the filler exceeds 80 per cent by weight), the physical prop-
erties of the mixture depend largely upon the pressure to which the
mass has been subjected. The greater the compression, the greater
will be the hardness, tensile strength and density.

Mixing increasing percentages of fillers with coal-tar pitch has
the following effects :

1 i ) The percentage loss on evaporation (figured on the weight
of coal-tar pitch in the mixture) is progressively decreased.

(2) The fusing-point of the mixture is increased in direct pro-
portion to the degree of fineness of the filler, irrespective of its
chemical composition.

(3) The difference between the fusing-point of the mixture,
before and after the evaporation test, is progressively decreased.

(4) The Ubbelohde dropping-point (Test i$h) of the mixture
is progressively increased.

(5) The difference between the dropping-point of the mixture,
before and after the evaporation test, is progressively decreased.

(6) The "breaking-point" (Test 13) of the mixture is pro-
gressively decreased.

(7) Different fillers influence the characteristics of the mixture
to a greater or lesser extent, depending upon their physical charac-
teristics, degree of subdivision, etc.

(8) Mixtures of two different fillers often give results superior
to the use of either filler alone.

Tests for load characteristics, compressibility and mechanical
strength, show the fillers named in the order of their superiority
for use in tar-concrete pavements: limestone, copper slag, sand-
stone, Portland cement, volcanic slag, slate, etc. 125

The effect of inorganic colloidal particles liberated "in situ"
(Type A-2-a) is shown in the following figures, obtained upon heat-
ing i kg. of residual oil at 400 F. for one hour with the metallic
salt named :

502

DISCRETE AGGREGATES
TABLE XLVIII

XXIV

Fu sing-point
(K. and S.)
(Test

Penetration
at 77 F.
(Test 9^)

Hardness
at 77 F.

Semi-asphaltic Residual Oil:

Untreated 102"

With 2 per cent ferrous sulfate 105

With 2 per cent aluminium chloride 114

With 2 per cent copper sulfate 1 1 8

With 2 per cent copper carbonate 118

With 2 per cent zinc chloride 130

With 3 per cent zinc chloride 142

With 4 per cent zinc chloride 162

With 5 per cent zinc chloride 168

Asphaltic Residual Oil:

Untreated 105

With 2 per cent copper sulfate 128

With 3 per cent copper sulfate 131

With 4 per cent copper sulfate 141

With 5 per cent copper sulfate 155

With 2 per cent zinc chloride 140

With 3 per cent zinc chloride 176

With 4 per cent zinc chloride 205

With 5 per cent zinc chloride 217

120

108

44
3*

68
60

5i
43

50
39

4-93

5-57
7-37
8.09
8.48
13.2

17-4
24.1
24.7

5-0

8-9

10 o

11.7

13 7
11.9
15 o
18 o

After treatment, the first series showed a bright lustre and the
second series a dull lustre.

CHAPTER XXV
BITUMINOUS SUBSTANCES DISPERSED IN WATER

Types of Bituminous Dispersions

These include bituminous-aqueous emulsions and suspensions.
A bituminous-aqueous emulsion consists of a dispersion of a liquid
or semi-liquid bituminous substance throughout water, and a bitumi-
nous-aqueous suspension consists of a dispersion of a semi-solid or
solid bituminous substance throughout water. A bituminous emul-
sion constitutes two liquid phases a bituminous phase and an
aqueous phase a "phase" being regarded as a physically distinct,
mechanically separable part of the system. A bituminous suspen-
sion constitutes a non-fluid or solid bituminous phase and a liquid
phase. Systems in which either a solid or a liquid is dispersed in a
liquid medium, are termed "sols," and if the liquid medium is
aqueous, the colloidal system is termed a "hydrosol," whereas if
the liquid medium is an oil, the system is termed an "oleosol."
The agglomeration, coalescing and deposition of the disperse phase
is termed "coagulation" or "peptization." The coagulation of sols
may be in the form of more or less definite particles, or of a jelly,
or of a flaky mass, usually termed "flocculcnt." The precipitate
formed is called a "gel." The dispersed particles are termed "mi-
celles" if they have absorbed another constituent on their surface,
with which they combine as the disperse phase. A substance which
renders dispersions stable, once they are formed, as well as to facili-
tate their formation, is termed a "dispersing agent," or a "defloccu-
lating agent," or a "peptizing agent." This is known as a "protec-
tive colloid" if a solid, and an "emulsifying agent," or "suspending
agent," or "stabilizing agent," if a liquid. The bituminous-aqueous
dispersion is said to have the bituminous constituent in the "exter-
nal" or "continuous phase" and the water in the "internal" or "dis-
crete phase," when the dispersion will mix readily with more of the

603

BITUMINOUS SUBSTANCES DISPERSED IN WATER AAV

bituminous constituents but not so readily with water. The bitu-
minous constituent is said to be in the "internal" or "discrete phase,"
and the water in the "external" or "continuous phase," when the
converse is true. However, it is possible to produce bituminous-
aqueous dispersions which will mix with either water or more of
the bituminous constituents with equal facility.

Certain colloids, when desiccated, will become re-dispersed upon
the addition of the dispersion medium, without any special manipu-
lation being required. Such colloids are termed "reversible," and
when the continuous phase is aqueous, are said to be "hydrophile"
or "lyophile" (i.e., water-loving) because of their ready re-disper-
sion in water. On the other hand, other colloids, on desiccation, do
not manifest this property, and are termed irreversible and are said
to be "hydrophobe" or "lyophobe" (i.e., water-fearing) when the
continuous phase is aqueous.

When a suspension and an emulsion are mixed, the non-fluid or
solid particles in the former coalesce with the liquid globules of the
latter, and viscous liquid or semi-solid globules are formed which
are prevented from coalescing by the protective colloid or emulsi-
fying agent, and thereby form a stable dispersion. Thus, although
the dispersing agent prevents the viscous globules from coalescing
with each other, it does not prevent the solid or non-fluid particles
from coalescing with the fluid globules.

Investigations on surface- and interfacial-tension enable us to
understand how dispersing agents effect a stabilization of aqueous-
bituminous dispersions. For example, at 20 C, the interfacial
tension between water and benzol is 35.0 dynes per cm. If, how-
ever, the water contains 0.4 per cent NaOH and the benzol 2.8
per cent of oleic acid, the interfacial tension is reduced to 0.04 dyne
per cm., or about o.ooi of the initial value. As an empirical rule,
it has been shown that dispersions are stabilized by substances form-
ing colloidal solutions or suspensions in water. The majority of
dispersions contain globules of varied dimensions, with the smaller
globules squeezed into the spaces between the larger ones. The
dispersing agent serves to inhibit the coalescence of the internal
phase and does not necessarily determine the degree of dispersion
attained. After evaporation of the water, the dispersing agent re-
mains in the bitumen as a "filiform," or honeycomb structure, which

XXV FORMS OF APPARATVS USED 505

serves to modify the physical properties of the film (i.e., fusing-
point, gloss, weather-resistance, etc,). 1

Forms of Apparatus Used. Two types of apparatus are em-
ployed to produce bituminous-aqueous dispersions : -*

(1) Agitators or "homogenizers."

(2) High-speed disintegrators, termed "colloid mills.' 1

Agitators are adapted to treating liquid or semi-liquid bitumi-
nous substances which may be readily broken up in the cold into
minute globules. Semi-solid or solid bituminous substances may
also be dispersed by means of agitators, if treated in the heated
state, and provided they melt below the boiling-point of water.
Similarly, solid bituminous substances may be dispersed in this type
of apparatus, provided they are first comminuted by grinding, atom-
izing, 2 or the like, and the powder agitated in the cold with cold
water containing the dispersing agent. A typical form of apparatus
consists of a jacketed vessel in which is suspended a metal cylinder
open at both ends, enclosing a vertical shaft carrying propellers
adjustable to varying heights on the shaft. By reversing the pitch
of the lower propeller, a powerful pull is created from the bottom
of the mixing vessel, while the upper propeller creates a downward
flow. The two opposing streams are thus forced against each other
and then thrust against the sides of the vessel with great force. In
this case the dispersion is the result of violent turbulence. A varia-
tion consists in using a revolving cylinder fitted with hollow trun-
nions carrying a horizontal, revolving shaft with a number of
beaters arranged to run in the opposite direction to that of the
cylinder and its contents. In all cases, it is desirable to run the
disperse phase into the external phase, so as to assist mechanically
the promotion of the dispersion. The dispersing agent is prefer-
ably carried in solution or suspension in the external phase. The
water containing the dispersing agent is first introduced through a
pipe, and while the propellers are in motion, the bituminous con-
stituents are gradually run in through another pipe, either in the
cold (if sufficiently fluid), or else in a molten condition. 8 The fin-
ished emulsion is drawn off at the completion of the operation and
cooled rapidly to room temperature. 4 Thus, in the case of an as-
phalt having a fusing-point of 150 F. (R. and B.) and a penetra-

506 BITUMINOUS SUBSTANCES DISPERSED IN WATER XXV

tion of 28 at 77 F., and with the use of clay as dispersing agent,
the following procedure is recommended: 30 parts of clay and 70
parts of water are introduced at 120 F.; J:hen the asphalt at
220 F. is gradually added under continuous stirring. The com-
pleted emulsion will consist of 6 per cent clay, 14 per cent water
and 80 per cent asphalt.

Other forms of agitators may consist of masticators, agitators,
ball-mills, pug-mills, chasers or Chilean mills, etc., 5 in which me-
chanical agitation is coupled with a certain amount of grinding or
trituration. These forms of apparatus are no longer used, as they
are comparatively inefficient. It may be stated in general, however,
that the efficiency of the agitator will depend upon the amount of
power or energy expended on the mixing operation.

Colloid mills have now supplanted the mechanical type of agita-
tors, since they not only form a better dispersion, but also consume
a smaller amount of dispersing agent, or even it is claimed, without
necessitating the presence of any dispersing agent whatever. 6 In
this form of apparatus, the dispersion is obtained by providing ad-
ditional mechanical energy in substitution of part, or all of the
dispersing agent. They are adapted to treating liquid or commi-
nuted solid substances in the cold, as well as all the types of bitu-
minous substances in the heated state, provided they melt at, or
near, the boiling-point of water. The colloid mill consumes con-
siderably more power than agitators, which accounts for its greater
efficiency in breaking up the bituminous substance into small globules
or particles.

Colloid mills effect a dispersion resulting in particles rarely less
than IM in diameter, which are actually larger than what is gener-
ally accepted as collodial dimensions, involving a particle diam-
eter not exceeding 200 m|j. Hence it is more accurate to refer to
this type of apparatus as a "dispersion mill'' rather than a colloid
mill. Furthermore, a sharp distinction exists between a "homo-
genizer" which operates under a pressure of 2000 to 3000 Ib. per
sq. in. and the colloid or dispersion mill, since the homogenizer is
not adapted for dispersions of solids or heavy liquids. Although
some pressure is utilized in the colloid mill, the main effect depends
upon the hydraulic shearing forces exerted upon the particles in the
presence of a fluid by the rotating surfaces. In the case of asphalts,

XXV

FORMS OF APPARATUS USED

507

the size of the dispersed particles is rarely less than ip; usually
about 3-6|j; the upper limit being about 15^ in diameter. The par-
ticles in the neighborhood of IM show Brownian movement, which
is absent in the larger particles. In the presence of a stabilizing
agent, the dispersions carrying the larger particles will remain
stable otherwise they are apt to "break" if the particles average
greater than 5^ (i.e. in the absence of a suitable stabilizing agent). 7

There are two general types of colloid mills, 8 viz. : beater-type
mills, in which the particles are subjected not only to hydraulic
shearing stresses, but also to impact stresses produced by revolving
blades operating between fixed blades. This operates on the batch
system and includes the original
Plauson machine and its subsequent
modifications, including the Hur-
rell mill. 10

The second consists of the
smooth-surfaced type, in which two
smooth surfaces in fairly close con-
tact are rotated at a peripheral
velocity of 2 miles per minute up-
ward, and a low-pressure pump
feeds the mixture between the dis-
integrating elements which consist
either of a truncated cone rotating
within a fixed cone, as illustrated in Fig. I35, 11 or two flat discs rotat-
ing in opposite directions, positioned either vertically, or horizontally
as illustrated in Fig. 136. In the latter type of machine, the ma-
terial is introduced through the shaft attached to one of the discs,
being thrown off the periphery of the discs into a chamber where it is
removed by gravity. In some cases the discs are roughened, so as to
augment the hydraulic shearing action. The moving elements have a
clearance of o.oo2-in. upwards and are operated at speeds of 3500
r.p.m. upwards. For each type of mill there exists an optimum speed,
or degree of agitation or mixing, and an optimum period of running-
time, whereby the most stable dispersion may be obtained for a
given system. In general, there is a speed above which the stability
of the dispersion decreases. The practical significance of this is
obvious, since an excessive expenditure of power is unnecessary.

FIG. 135. Smooth-surface Type of Col-
loid Mill -with Truncated-cone Work-
ing Surfaces. A Material inlet; B
Working surfaces; C Material outlet.

508

BITUMINOUS SUBSTANCES DISPERSED IN WATER

XXV

Solids should always be subjected to a preliminary grinding to not
less than 80 mesh, and generally finer, depending upon the clear-
ance at which the mill operates. A form of mill has been proposed
to accomplish this, consisting of a pair of rotating discs with pro-
jecting vanes or pins. 13

Among the factors which influence the dispersion are tempera-
ture, hydrogen-ion concentration and the
protective colloid or dispersing agent
used.

The effect of rise in temperature is in
general to make the dispersion easier.
For non-miscible liquids, rise in tempera-
ture is accompanied by a decrease in the
interfacial tension, a condition favorable
to dispersion. A colloid mill will effect
the dispersion with a smaller amount of
dispersing agent than if merely agitated
mechanically, as may be illustrated by
the following figures: 100 parts of water
are heated to 90 C. and 3.5 parts caus-
tic soda and 25 parts oleic acid are
added. The resultant mixture, contain-
ing 20 per cent by weight of sodium
oleate is diluted with 9 times its volume
of water heated to 90 C and then run
through a colloid mill with an equal
amount of asphalt heated to not exceed-
ing 1 00 C. The resulting emulsion con-
tains equal parts of asphalt and water,
with i per cent by weight of soap, or in
other words 50 times as much asphalt as soap. 14 On the other hand,
by using an agitator of the average efficiency, the best that may be
accomplished with the same ingredients is to form an emulsion with
about 25 times as much asphalt as soap, even though the former is
introduced in installments. 15

Character of the Bituminous Substance. They may either be
soft or hard. Soft substances may be dispersed at room tempera-
tures, or with the application of a moderate amount of heat Hard

FIG. 136. Smooth-surface Type
of Colloid Mill with Opposed-
disc Working Surfaces. A
Material inlet ; B Working sur-
faces; C Material outlet; JD
Cooling-water inlet ; E Cool-
ing-water outlet.

XXV ORGANIC SUBSTANCES 509

substances may either be pulverized and dispersed at room tem-
perature, or else melted and dispersed in the fluid state. Prac-
tically every form of bituminous substance has been proposed for
dispersions, including: natural and artificial asphalts; coal tar and
coal-tar pitch; various mixtures, such as asphalt fluxed with low-
temperature tar. 16

Character of the Dispersing Agent. The following constitute
the principal types of dispersing agents which have been proposed
from time to time for use with bituminous substances. 17

(A) INORGANIC SUBSTANCES

(1) Hydroxides. Including: FeOH 3 , A1OH 3 , CaOH 2 ,
BaOH 2 , etc. 18

(2) Oxides. Including: Fe 2 O 3 , Al a O 3 , CaO, MgO, BaO 2 ,
ZnO, CuO, Pb 3 O 4 , etc.; 19 various forms of silica, such as silica gel
(i.e., hydrated silicic acid) ; 20 infusorial earth; 21 sand. 22

(3) Silicates. Including: soluble silicates (e.g. Na 2 SiO 3 ); 23
insoluble silicates (e.g. Fc, Al, Ca or Mg such as talc, soapstone,
hydrous magnesium silicate, etc.); 24 colloidal clays 25 inclusive of
bentonite; 26 spent fuller's earth; 2T Portland cement; 28 soil or earthy
matter; 29 etc.

(4) Sulfates. Including gypsum (plaster-of-Paris). 80

(5) Phosphates. Such as tri-sodium phosphate or sodium-
hydrogen phosphate. 81

(6) Sulfides or Polysulfides. Such as Na 2 S or K 2 S (with or
without Na 2 CO 3 ) ; 32 arsenious sulphide; 83 etc.

(7) Alkalies. These form "soaps" with bituminous substances
containing saponifiable constituents (e.g., wood tar, rosin pitch, lig-
nite tar, montan wax, fatty-acid pitch, certain coal tars, certain as-
phalts, etc.) , and include : NH 4 OH, KOH, NaOH, K 2 CO 3 , Na 2 CO 3 ,
borax, etc.; 34 alkalies plus an asphalt solvent (e.g., benzol). 86

(8) Miscellaneous. Including calcium arsenate, basic cad-
mium sulfate, etc.

(B) ORGANIC SUBSTANCES

(1) Fats and Oils. Such as cholesterol alone; 86 sulfonated
cholesterol ; ar cholesterol with H 3 BO 3 or H 3 PO 4 ; 88 stearic acid with
diethylene or triethylene glycoL 80

(2) Resins. As for example synthetic resins (e.g. phenol-
aldehyde, or cumarone) with or without alkali. 40

510 BITUMINOUS SUBSTANCES DISPERSED IN WATER XXV

(3) Soaps. Including combinations of NH 3 , K t Na, Mg, and
Ca, with fatty acids or resin acids (e.g., fats, fatty-acids, saponi-
fiable oils, cholesterol, fatty-acid pitch, wood tar, wood-tar pitch,
rosin, rosin pitch, montan wax, lignite tar, etc.) ; 41 ammonium lino-
leate or trihydroxy-ethylamine stearate, sulfates, etc.; 42 triethanol-
amine oleate; 43 glycerinmonostearic-acid ester and amino-ethylene-
amido-chlorhydrate ; 44 soap and cyclohexanol ; 46 crude lignite wax
and alkali; 46 etc.

(4) Sulfonated Vegetable Oils. Including turkey-red oil; 47
metal sulfonates (with glycerin, etc.), 48

(5) Sulfite Liquor (derived from alkali-cellulose manufacture).
Includes the use of sulfite liquor alone; 49 with slaked lime; 50 with
Fe, Al or Cr sulfate; 51 also sulfite-cellulose pitch. 52

(6) Mineral-Oil Derivatives. These include polymerides of
olefin (i.e. alkaline oxides) ; 53 naphthenic acids and their salts (i.e.
sulfo-derivatives, acid sludges, oxidation products, etc.) ; 54 aromatic
sulfo-derivativcs (e.g. "kontakt") ; 55 oxidized paraffin wax with or
without NaOH; 56 oxidized mineral oil products (e.g. blown with
Na 2 CO 3 and NH 4 -stearate) ; 67 chlorinated mineral oil derivatives; 58
residues from cracking processes (e.g. "Dubb's Sludge") ; 59 etc.

(7) Carbonaceous Matter. Such as powdered hard bitumi-
nous substances; 60 powdered lignite, brown-coal or oil shale; 61 pow-
dered bituminous coal; 62 carbon black; 63 etc.

(8) Alkaline Bases. Including pyridines, amines (e.g. tri-
ethanolamine), cresylates, piccolin, quinolin, etc.; 64 resorcinol, pyro-
gallol, a or 0-naphthol, carbazol, etc. 65

(9) Proteins or Proteids. Include alkaline caseinates, albu-
min, lecithin; 66 vegetable proteins (e.g. soya-bean flour); 67 muci-
laginous extract from linseed or flaxseed hulls. 68

(10) Albumenotds. Such as glues and gelatines. 69

( 1 1 ) Pectins. Include the various gels. 70

(12) Gums and Algae. Such as gum-Arabic (acacia), traga-
canth, various seed-gums, agar-agar, Irish-moss (carrageen moss)
etc.; 71 algin; 72 alkaline alginates (e.g. seaweed and alkali); 73 etc.

(13) Polysaccharides and Hemicelluloses. Such as starch,
dextrine, glucose and soluble carbohydrates, with or without alkali ; 74
molasses residues with CaOH 2 ; 75 etc.

(14) Tannins. Include tannic acid, alkaline tannates, heavy
metal tannates, various bark extracts, saponin (soap bark), lignins,
humic acid and alkaline humates (from turf, peat, brown-coal, de-
cayed vegetable matter, etc.). 78

(15) Miscellaneous. Include glycerin residues obtained on
distilling glycerin; 77 viscose ; bile salts (e.g. oxgall) ; r9 0-tetra-
hydronaphthalene ; 80 etc.

XXV VARIOUS COMBINATIONS 511

1 I ) Clay in Combination With : Inorganic hydroxides ; 81 alka-
line silicates or metal fluosilicates ; 82 Portland cement; 83 alum or
sodium-hydrogen phosphate; 84 phosphoric, chromic, oxalic or ben-
zoic acid; 85 alkalies; 86 soaps of various kinds; 87 sulfite liquor; 88
alkaline casemates; 89 glue or gelatine; 90 starch paste; 91 tannic acid
or alkaline tannates ; 92 tri-cresyl phosphate ; 93 etc.

(2) Sodium Silicate in Combination With : Slaked lime
(CaOH 2 ) ; 94 or rosin. 95

(3) Soaps in Combination With: Alkaline silicates; 96 sodium-
hydrogen phosphate; 07 borax; 08 sulfonated vegetable oil; 99 phenol-
sulfonic acid; 100 alkaline casemates; 101 glue or gelatine; 102 gums
(e.g. algae jelly or carrageen moss) ; 103 starch paste (or farina-
ceous protein) ; 104 tannic acid or alkaline tannates; 106 etc.

(4) Sulphonated Vegetable Oils in Combination IVithi Alka-
line casemates ; 106 glue. 107

(5) Alkaline Caseinates in Combination With\ Agar-agar ; 108
alkaline tannates; 109 the latter it is claimed will form exceedingly
fine-grained dispersions which will not "break" readily even when
ferrous sulfate is added.

(6) Glue or Gelatine in Combination With\ Aluminium salts
(e.g. A1OH 3 or aluminium acetate) ; 110 molasses; 111 etc.

(7) Tannic Acid or Alkaline Tannates in Combination With:
Starch paste; 112 tri-sodium phosphate; 113 etc.

Slow-setting, "stabile" dispersions are prepared with the use
of inorganic hydroxides, clay, and other water-insoluble dispersing
agents. Such dispersions will not break upon adding electrolytes,
inorganic fillers (e.g. sand, silicates, asbestos, Portland cement, pig-
ments, etc.), or organic fillers (e.g. wood flour, cork powder, etc.).
Quick-setting, "labile" dispersions are prepared with the use of
soaps and other water-soluble dispersing agents. Such dispersions
will break rapidly upon adding inorganic or organic fillers. The
speed of setting may be regulated by mixing together water-insolu-
ble and water-soluble dispersing agents in suitable proportions; or
by mixing together a rapid-breaking dispersion with a slow-breaking
variety. 114 The use of dispersing agents in verious combinations
(Group U C") not only gives better results than the use of one agent
alone, but also effects a saving in the quantity required to accom-
plish a given result. Water-soluble dispersing agents are known as
"stabilizing agents." 116

512 BITUMINOUS SUBSTANCES DISPERSED IN WATER XXV

The addition of the following materials is claimed to retard
the breaking of dispersions: an acid in the presence of Na or K
fluoride, oxalate, tartrate or fluosilicate ; 116 an