UNIVERSlTYo/tALIFQRNIA

BEQUEST OF

5AM UELBENEDICTCHRISTY

PROFESSOR OF MINING AND METALLURGY

1885-1914

GEOLOGICAL SURVEY OF MISSOURI.

IR/IBIFOIR-T

ON

LEAD, ZINC AND IRON,

TOGETHER WITH

NOTES ON SHANNON COUNTY

AND ITS COPPER DEPOSITS.

BY CHARLES P. WILLIAMS, PH. D.,

ACTING STATE GEOLOGIST.

JEFFERSON CITY.

REGAN & CARTER, STATE PRINTERS AND BINDERS.

1877.

SESSION ACTS, PAGE 20.

That the sum of fifteen hundred dollars be and the same is hereby appropriated, out of any money in the Treasury not otherwise appropriated, chargeable to the Reve- nue Fund, for the printing of five thousand copies of the report of the Acting State Geologist.

REPORT.

To His Excellency, CHAS. H. HARDIN, Governor of Missouri :

SIR : I have the honor to forward herewith the report of the operations of the Geological Survey in the direction of an examina- tion of the conditions surrounding certain of the prominent industries of Missouri.

The economical aspects presented in the production of two of the great staples of the State have been investigated with considerable detail by a study of the means, appliances, and the chemical prob- lems connected with the manufacture of the metals, lead and zinc. Some attention has been given to the iron industry as well, but the general stagnation of this great business has manifested itself by such a decrease in the activity of the furnaces of this State, that facilities were wanting for the collection of sufficient data for any- thing approaching that comprehensive and thorough study which the importance of the subject demands. The production of charcoal iron is, however, presented with some degree of fullness.

In shaping the work intrusted to me by the Board of Curators of the State University, towards the attainment of the ends indicated, I have been influenced by the fact that while a large amount of the structural geology of the State, and the special geology of its mineral deposits had already been made public in the reports of Messrs. Swallow, Pumpelly, Broadhead and others, but little had been accu- mulated towards unfolding the history of the technology which the conversion of the raw materials from those mineral deposits into com- mercial products had created within the borders of Missouri. Fur- ther, the appropriation of five thousand dollars yearly was not ade- quate to keeping in the field a force sufficient for thorough and rapid work in those counties which had not before received special atten- tion.

The material which could be collected under existing circum- stances is not full enough for a geological history of those counties; however, as interesting copper occurrences have long been known to

303803

EEPORT.

exist within the limits of Shannon county, some space has been devoted to a geological history of those deposits, this course being regarded as in accord with the design of this report.

Notes on the supposed gold deposits of Northern Missouri have also been given in the appendix.

I must acknowledge, in this connection, the very efficient assist- ance rendered in the laboratory by Mr. A. W. Hare. His zeal and industry have enabled me to make a much fuller presentation of the chemical illustrations of the work than could have been done other- wise.

Other aid, whenever rendered, is acknowledged in the report.

Some of the notes on the St. Louis industrial district collected, by Dr. Adolph Schmidt, have been used with his sanction. These notes, having been taken as early as 1872, have lost much of their value in the lapse of time and the progress and growth of the industries^ and their reproduction would only extend this report without pre- senting the actual conditions of the manufactures to which they relate. Much of present value is contained in Dr. Schmidt's notes on the iron deposits, but as an account of these was foreign to this pres- ent work, these notes have not been reproduced.

All of which is respectfully submitted.

Your obedient servant,

CHAS. P. WILLIAMS,

Acting State Geologist ~ ROLLA, Mo., December 13, 1876.

LEAD INDUSTRY

CHAPTER I.

MINERALOGY AND GENERAL METALLURGY OF LEAD.

The geological positions and modes of occurence of the ores of lead throughout Missouri have been described in such detail in pre- ceding reports, that this report is restricted to a discussion of the eco- nomical considerations connected with the conversion of those ores into marketable lead. The facts that the lead bearing formations occupy a very considerable part of the area of South Missouri, and that those formations contain concentrations of plumbiferous miner- als, of which many have been strikingly remunerative, are known much more generally than are the character of the ores, the features of their metallurgical treatment or the commercial value of the pro- duct as a factor in the material wealth and prosperity of the common- wealth.

The pressure of a large and rapidly increasing production from the mines has left little time for examination or discussion of those smelting methods, which, adopted in the early development of the lead industry, have been reproduced with but trifling modifications at each new mining centre. At the present time when lead produc- tion has become a permanent industry in the State, and Missouri brands of metal are in competition with refined leads from other domestic, as well as from foreign establishments, in the markets of the east, it may be wise to scrutinize the common metallurgical practices of the State more closely than has heretofore been done, in order that the fullest possible advantage may be gained from them.

Among the various methods of lead smelting and the wide range of variations which local conditions and experiences have added to them, there are but few which have any extended use in the State, and it is these alone which need be examined in detail to ascertain how far the practice, which is in general adapted to the ores to be treated, is worked to its fullest capabilities or, in other words, how nearly its utmost advantages are realized. To reach this knowledge, some account must be taken of the experiences and results elsewhere, and the comparisons which will be thus instituted will not only explain the local practice, but furnish suggestions which may be adopted with advantage leading to cleaner work and closer economy.

8 LEAD FURNACES AND PRODUCTS.

A consideration of the metallurgical processes involved in the production of metallic lead necesitates a knowledge of the composi- tion of the ores and of those associated minerals which influence the furnace operations or affect the quality of the resulting metal. A description of the mineral species occurring in the lead deposits is therefore given, and their composition generally given from the results of chemical analyses. This has been followed by a short account of the various practices of lead smelting, including the rela- tions of the foreign minerals to the operations and to the product and a fuller discussion of the chemical changes taking place in those methods which are in service in Missouri, together with descriptions of the apparatus in which these changes 'are brought about and illus- trations furnished by analyses of the intermediate and final products.

GEOGRAPHICAL DISTRIBUTION OF LEAD ORES.

The classification of the lead regions of the State recognizes three chief areas of lead developments, denominated, respectively, the South- western, the Central and Southeastern districts, a distinction in the main geographical, though warranted to some extent from a scientific standpoint by geological features peculiar to each.

The Southwestern Lead Region — This includes the counties of Jasper and Newton, as those in which in the most active develop- ments have been made, besides Greene, Dade, and portions of McDon- ald, Barry, Stone and Christian counties. The ores are found in the sub-carboniferous system — notably in certain upper members of the Keokuk or Archimedes limestone. The productive rocks have a thickness of about 125 feet, consisting, in a descending order, of (a) more or less broken and softened chert, accompanied by larga masses of clay and sand, (20-75 feet), (b), a silicious limestone (occasionally wanting and never exceeding 20 feet thickness), and (c) a maximum of thirty feet of alternate layers of limestone and chert. This pro- ductive series rests upon upwards of 140 feet of unproductive limestone, distinguished as the bed-rock.*

The Central Region — The principal points of development of this region are found in the counties of Miller, Cole, Morgan and Moni- teau, but the district includes in addition to these, Saline, Cooper, Pettis, Benton, St. Clair, Hickory, Camden, Osage and Maries. In parts of Moniteau and in Saline and Cooper counties, the deposits are found in the same horizon as in the Southwestern region, viz : The Archimedes limestone, and therefore, a description other than a geo-

* For full descriptions, consult Schmidt & Leonhard, in Broadhead's Report for 1873-1874, page 401 et seq.

LEAD FURNACES AND PRODUCTS.

graphical one would include these in the Southwestern rather than in the Central region.

In the other counties named, the workable deposits of lead miner- als are found in members of the lower silurian system, the second magnesian limestone being the chief productive rock in the northern and western parts of the region, while the third magnesian limestone constitutes the horizon of the deposits of the southern and eastern.

The Southeastern Lead Region: The seats of the most active operations are found in the counties of Franklin, Jefferson, Washing- ton, St. Francois, Madison and St. Genevieve. To this list may be added the counties of Crawford and Bollinger, within the limits of which lead deposits have been found and developed to some extent.

The productive geological formation in this area, is the third mag- nesian limestone, which, excluding the southwestern and portions of the central regions, is the great lead-bearing series of the State. It therefore has a wide extent, preserving, over the great area in which is found a remarkable uniformity of character, * and is nearly a true dolomite, containing the calcic and magnesic carbonates in the pro- portion of one to one. It has a large vertical range, having a thick- ness, where entire, of probably more than five hundred feet.

To the three areas above indicated, may be added a fourth, The Southern — including a large extent of country, underlain by the mag- nesian limestone series, and in which lead ores have been discovered, either in situ or as float mineral, but in which there has been little, if any, systematic exploration. Some little work or casual examina- tion has resulted in the discovery of lead ores in the counties of Phelps, Texas, Wright, Douglas, Webster, Christian, Taney, Stone, Barry, Laclede and Dallas.

OKES AND ASSOCIATES.

In the classification adopted by metallurgists, sulphuretted ores are distinguished from the oxidized ores. The first class includes but one species of any practical importance in the production of lead, viz : galenite ; the second class includes cerrusite, anglesite and pyro- morphite, all of technical importance, but still subordinate to galenite. Galenite (Von Kobell) : This species, commonly called Galena, and, by the miners, " mineral," is emphatically the ore of lead. Chem- ically it is lead sulphide, containing, by theory,

1 atom of lead 207 or 86.61 per cent.

1 atom of sulphur 32 or 13.39

1 molecule lead sulphide 239 10000

* Swallow's First Annual Report; Schmidt and Leanhard, loc. cit. ; J. K. Gage, BroadheacPs Report, page 601 et seq.

10 LEAD FUKNACES AND PRODUCTS.

Usually it is contaminated to a greater or less extent by various other metallic sulphides or by intermixture of certain earthy substan- ces (gangues), either loosely associated with it, or so intimately dis- seminated through it as to be unrecogizable by any other than chemi- cal means.

Galenite crystallizes in the isometric system, usually in cubes, or in cubes with planes of the octahedron or dodecahedron. The cleav- age is ordinarily cubical and perfect; occasionally traces of the octa- hedral cleavage are observed. This latter is particularly noticed in the galenite from the Pequa Mine, Lancaster county, Pennsylvania. * Large cubical crystals are of common occurrence at many of the local- ities of this State, and specimens of this description, measuring up- wards of three inches edge are not infrequent. It is also found tab- ular, and passing from coarsely crystalline through many grades to the finely granular, the last constituting the steel-grained ore. Its color is lead-gray; lustre, metallic; fracture generally even, more rarely subchonchoidal ; hardness 2.5 — 2.75 ; specific gravity, 7.25 — 7.75 — a cubic foot of the solid mineral, therefore, weighing from 435 to 484 pounds.

Though distinguished among the mines of this State, by the-names of mineral or blue mineral, the galenite receives various other namesr according to the variations in the forms and modes of occurrence. When it occurs as large or coarsely crystallized masses, it is generally called block or chunk mineral ; smaller crystals constitute the cog> mineral, while still smaller crystals are denominated dice mineral.

Among the foreign matters found in galenite, either in a state of mechanical admixture, or in various forms of combination, or as iso- morphus replacements of either the lead or sulphur, are, silver, gold^ antimony, arsenic, copper, cadmium, zinc, iron and nickel ; more rarely, selenium, and, reputed in the galenite from the Dept. Char- ente, France, platinium. f Notable amounts of these matters influ- ence the metallurgical treatment of the ore, and the quality of the product from it, while, in some cases the presence of those metals of much greater value renders the lead a subordinate product of the ore, or causes it to act as an adjunct to the extraction of those metals.

Silver is rarely, if ever, absent. J It occurs occasionally in the galenite, in the free or native state ; commonly it exists as argentic sulphide, isomorphus with and replacing more or less of the lead sul- phide. This is believed to be the form of combination in cases in

* Genth's Preliminary Report on Mineralogy oj Pennsylvania, p. 12. f Dana's System of Mineralogy.

J The same claim is made for gold. See, on this point, Percy's Metallurgy of Lead* page 96, et seq.

LEAD FURNACES AND PRODUCTS. It

which the silver does not exceed one per cent, of the galenite; in ores richer than this, the silver is regarded as occurring as some one or more of its ores mechanically iLixed through the galenite. Mala- guti and Durocher examined a large number of specimens of galenite and found the silver to range in amount between a mere trace, and upwards of 7 per cent.*

A somewhat popular belief is to the effect that the texture of the galenite is, in some measure, an indication of the relative amount of silver it contains, the finely granular varieties being regarded as relatively richer, and the coarsely granular or crystalized, as poorer. This view is not supported, either by chemical analyses or by experi- ence, and is, therefore, not to be relied on. The coarsely granular gale- nite from some localities, e. g. Arizona (according to Kiistel), is deci- dedly richer in silver than the finer varieties. The argentiferous char- acter is decidedly more closely connected with the character of the deposit furnishing the galenite, and with the structure and lithologi- cal characters of the rocks enclosing the deposits, than with the tex - ture of the ore itself; but even these fail as reliable indications, or hold good only for well established silver-bearing districts. Assays of the ores from a newly discovered or opened mining region are the only trustworthy guides in this direction.

The galenite from localities in this State are not argentiferous in any practical sense. This has been so well established by repeated assays of the ores, and has been so fully substantiated by analyses of the leads produced from them that, were it not for the fact that por- tions of the State are very frequently excited over reported silver discoveries within the limits of Missouri, it would not be necessary to make more than a passing allusion to this fact of the invariable ab- sence of notable amounts of silver from our ores. Periodically re- ports appear of discoveries of rich silver ores, the search for which originates from some vague tradition connected with De Soto's expe- dition, or with the mythical silver mining Indian, and which generally have no more substantial basis than a few specks of calcite or pyrites in a limestone, or at the best, the discovery of a galenite of fine- grained texture, f

I have collected the following results of the estimation of silver in the galenas from various parts of the State, the results being given both in per centage and in the customary manner of ounces to

* Annales des Mines, 4 Ser. vol. xvii, 1855.

f These are facts within my own experience, for I can count upwards of fifty cases where limestone has been brought to me for silver ore. In a number of cases, yielding to the importunities, assays have been made, it is needless to say with what result, and without carrying conviction.

12

LEAD FURNACES AND PRODUCTS.

the ton of two thousand pounds of ore, and are accompanied, wher- ever it was known, by the per centage of pure galena, or lead sul- phide in the ore :

LOCALITY.

SILVER, PER CENT.

SILVER OUNCES, PER TON.

PER CENT. GALENITE IN THE ORK,

I.

Mine La Motte

0027

086

II.

.0025

0.80

III.

Mine La Motte

0012

038

IV.

Perry's Mines

0009

029

"Well Crystalized."

v.

Potosi Mining Company

.0012

038

VI

Village Di QpDpin °*s GJranbv

0031

100

VII. VIII. IX.

X.

XL

Holman Diggings, Granby Trent Diggings, Granby.. East Point Diggings, Granby.. Temple Diggings, Joplin Swindle Diggings, Joplin

.0039 .0039 .0052 .0039 . .0021

1.25 1.25 1.75 1.25 0.75

9705 9686

97.24 97.79

XII.

.0031

1.00

9634

XIII.

Jefierson county

.0114

3.75

91.84

XIV.

Franklin county

.0021

0.75

93.09

XV.

Phelps county

.0009

029

47.87

XVI.

Phelps county

.0038

1.25

9336 -

XVII.

Maries county

.0039

1.25

94.00

XVIII.

Pulaski county

.0029

0.87

89.12

XIX.

Wright county

.0030

1.00

84.29

XX.

Laclede (?) county

.0030

1 00

87.00

XXI.

.0011

0.36

8997

XXII.

none.

none.

99.34

sxm.

trace.

9989

SXIV.

Morgan county

trace.

98.76

XXV.

Morgan county .

none.

9987

SXVI.

.0124

400

•'Pure."

Assays I to V are by Dr. Litton, (Swallow '$ Report, 1854 and 1855); VI to XII, Chauvenet (Broadfieatfs Report, 1873 and 1874); XIII to

LEAD FURNACES AND PRODUCTS. 13

XXI, by myself, or under my direction in this laboratory; XXII to XXVI by Chauvenet (loc. cit.)

The number of assays and the range of localities might have been greatly extended, but enough has been given to show the quality of the Missouri galenite, in respect to the amount of silver contained- The maximum amount thus far found, is in the specimen from Jack's diggings, Mine la Motte, (XXVI in the list), and gives a value of $5.16 per ton of similar ore. This value is entirely too small to cover expenses of desilverization, even if the separation of silyer and lead could be fully made in practice. Reference to the various analyses of the pig lead from the furnaces using ores from the mines of Missouri will show that the amount of silver present in these ores must have been small and scarcely noteworthy.

Antimony is of very frequent occurrence in galenite, upwards of five per cent, being recorded as existing in the ores from some foreign localities. It probably exists as antimony tri-sulphide (stibnite) either alone or combined with other metallic sulphides, and disseminated through the galenite. In whatever form of combination, its presence is objectionable, for its separation by known mechanical means is impossible, and its presence in the furnace causes loss of lead (and silver) by volatilization, and impairs the quality of the metallic lead.

Careful analyses, made either by myself or under my direction,, were undertaken to determine the existence of antimony in the Mis- souri galenites, and its amount, if found to exist. Numerous speci- mens of ores, pig leads and slags have been examined, usually operat- ing on large amounts, and while the results show that antimony is almost invariably present, it always occurs in amounts too small to exert any marked influence either on the smelting processes or the resulting lead. Its existence in the galenites of Missouri is therefore a point more of scientific interest than of technical importance. (For results see table of results of analyses, galenites, pages 16 and 17, also analyses of pig leads from the various furnaces.)

Arsenic has been found in faint traces in some of the ores, and shows in small amounts in the metallic leads produced in the State. It operates in the same direction as antimony, but the remarks above concerning the latter apply equally to the arsenic.

Zinc as sulphide (sphalerite or llende, the Hack jack of the miners), occurs int association with galenite, either intimately mixed with and disseminated through it, or so coarsely associated with it that each mineral is easily distinguished by the eye. In cases of intimate mixture or dissemination, mechanical preparation will not effect any-

14 LEAD FURNACES AND PRODUCTS

thing approaching a thorough separation of the two materials, while in the other cases hand-sorting will relieve the galenite largely of its associated blende. Its action in the furnace, within certain limits, is not sensibly injurious beyond the increased loss of lead by volatiliza- tion, nor is its presence sensibly felt in the metallic lead, for the latter does not appear to be able to take up in the furnace but a very small per cent, of its weight of metallic zinc.

Cadmium^ where found, is probably an associate of the sphalerite rather than of the galenite. In selected specimens of nearly pure galenite, it is found only in mere traces, and I have been able to find it in the metallic lead in but one case, and that of metal produced from the treatment of slags. (Granby slag lead, 0.00298 per cent, cadmium.)

Both modes of association of the blende and galenite are common in the lead deposits of the State, but the most frequent is that of loose association, which permits of easy separation of the two minerals. Large amounts of blende are thus produced as an incidental or subor- dinate product of the lead mines of the State. These matters will be more fully treated in the section of the report devoted to the zinc industry of the State, but the annexed analysis of blende may not be without interest in this connection.

Analyses I. was made under my direction by Mr. John D. Greason, the specimen showing a small amount of calamine and giving a separa- tion of gelatinous silica, on treatment with acid. The silica is there- fore assumed as existing as calamine, and from it the amount of the other constituents (zinc, oxide and water) were calculated. The speci- men was from Granby, Newton county, and was of a yellowish-brown color. The association of blende and calamine is not uncommon, and is thus described by Schmidt (loc. cit., page 391) :

"In many places the blende seems to pass gradually into cala- mine, there being between the two minerals a layer of dark colored, fine-grained blende, intimately mixed with portions of columnar struc- ture, and resembling calamine. This mixture passes into regular columnar or fibrous calamine, which itself is dark colored near the blende, and is lighter and more transparent the more remote it is from the unaltered blende. Single crystals or large crystalline aggre- gations of blende are often surrounded by a thick layer of calamine of botryoidal form and radiating columnar structure. The surface of the enclosed piece of blende is then generally corroded and tarnished. Blende, especially the coarsely crystalline variety, is often intimately mixed with galena. Mr. Broadhead observed, at Leadville, round globules of from one-sixteenth to one-eighth inch in diameter, grayish-

LEAD FURNACES AND PRODUCTS. 15

ferown color, and radiating fibrous structure, on crystals of galena. Mr. Ohauvenet analyzed them, and found them to be pure sulphuret (sulphide) of zinc, without any iron or lead."

Analyses II and III are by Mr. Chauvenet (loc. cit.):

II. III.

Leadville. Joplin.

[Chauvenet] [Chauvenet] 64.87 65.92

0.37 0.32

0.623 0.509

Zinc

I.

Granby. [Grease n.] 61 934

0788

0043

Antimony.. • ••

0001S

31269

("Silica

0.911

"Calamine,

2.461

[Water ,

0.231

["Lime

1 361

Gangue

1 Magnesia .

0043

Carbonic acid...

1.148

1.410 1.250

Iron occurs probably as pyrite, which is not objectionable in the furnace charge in small amounts ; or perhaps in some ores as mis- pickel or arsenical pyrites, which introduces arsenic into the lead.

Copper, in the form of chalcopyrite or copper pyrites is notice- able in the galenite from some of the localities of the southeastern district (St. Joe Mines, Mine la Motte). Smaller amounts of copper pyrites are found associated with the ores in almost all the deposits of the southwestern and central districts. Other forms of copper combinations or minerals doubtless occur in the galenite, for very few specimens but give small amounts of copper on chemical analysis, though no chalcopyrite or other copper-bearing mineral can be dis- tinguished under the magnifying glass.

Nickel and Cobalt are found in notable amounts in association with the lead ores from the Mine la Motte property, and are a source of profit in the metallurgical treatment of those ores. Other local- ities in the southeastern district also yield nickel-bearing minerals as associates of the lead ores, and traces or small amounts of nickel are found in many specimens of apparently pure mineral from many localities in the southwestern, and, more rarely, from some in the cen- tral region. Most pig leads smelted in the State show small but still appreciable amounts of nickel on careful analysis.

The results of analyses of ores from various Missouri localities will exhibit the character and amounts of the foreign metals — excluding the silver — found in the galenite mined in this State. No estimations

16

LEAD FURNACES AND PRODUCTS.

were made of the sulphur and lead, because, as the specimens were generally selected as being free from visible admixture of foreign sul- phides, such estimations would have no practical significance. Effort was made to have the specimens analyzed as free as possible from earthy gangues, but wherever otherwise, note is made in the descrip- tion of the locality :

FOREIGN METALS IN APPARENTLY PURE GALKXITE.

Per cent, other foreign metals.

Nickel.. .0660

Southwestern

Region.

Per cent.

Per cent.

Per cent.

Per cent.

Antimony

. Copper.

Iron.

Zinc.

I

trace.

trace.

.05867

.06782

11

07429

.00478

.02169

.00938

Ill

00551

.00239

.08602

1.35554

IV

, 03323

.01038

.13020

2.02701

V

02784

.03724

.08400

1.31648

VI

00709

.01517

.15260

2.22539

VII

02764

.01677

.03220

1.7655S

VIII

trace.

none.

.12040

.14679

JX

.09240

.10601

x:

04912

none.

.10640

.07320

XI

.5880

61.96314

XII

.07040

.08771

XIII.

32194

.0423*

.02870

.02011

Central Region.

XV

.04178

trace.

.02310

.00804

XVI

16545

.15141

.05040

1.26352

XVII ,

00317

.00798

.07050

.00268

XVIII

00475

.01197

.00980

.00602

XIX

04754

none.

.02940

trace.

XX

trace.

none.

.02240

.00372

XXI

trace.

none.

.78400

.00019

XXII

00392

.02151

.02513

.03945

Southeastern

Region.

XXV

05069

4.6557

8.1304

.3255

XXVI,

.00400

.0730

1.681

.2150

XXVII

032

.097

1.583

.339

cxvm

trace.

none.

2.529

.040

*

XXIX.

trace.

.080

1.953 .

none.

XXX...

trace.

.103

1.435

trace.

Ni trace.

Ni 09755

Cd...

trace.

(As...

\ Ni... (Co...

.002 .012 .023

iAs...

.003

Ni...

.031

Co...

.019

Ni...

.214

Co..

trace.

(Ni... jCo...

.168 .357

jNi...

.213

1 Co...

.042.

LEAD FURNACES AND PRODUCTS.

17

Southeastern Region.

Per cent. Antimony.

XXXI 010

XXXII none.

XXXIII 031

XXXIV 004

XXXV... trace.

XXXVI.

none.

Per cent. Copper.

.009

Per cent. Iron. .118

Per cent. Zinc. .034

Per cent, other foreign metals. As trace.

none. .041

.05180 .011

.0136 .054

Ni&Co.. traces. As .026

trace .

.055

.015

As 009

.754 13.319 0.798

.494 13.517 2.244

.374

.020 0.611

As trace.

/Ni... .233 1 Co... trace.

M&Co.0.137

0.167

1.559

1.276

* ' 0.573

0.040

0.067

0.237

' ' 0.042

0.091

0.823

0.670

« ' 0.078

XXXVII none.

XXXVIII trace.

XXXIX trace.

XL.... trace.

No. I. Washed galenite from jig at Granby, Newton county; II, block mineral. Jasper county, Joplin ; III, block mineral, Granby ; IV, V and VI, washed mineral from jigs at Granby ; VI, Holman's diggings, Newton county. Chauvenet's analysis of ore from these dig- gings shows: (loo. Git. page 388,) lead, 84.06; zinc, 0.94; iron, 0.16; antimony, none ; silver, 0039 [=li oz. per ton of 2000 Ibs. ore] ; silici- ous matters, 0.61 per cent. The lead corresponds to 97.05 per cent. galenite, and the zinc, to 1.41 per cent, sphalerite ; VIII, Birch dig- gings, Joplin, Jasper county; IX, another specimen from same local- ity as VIII; X, XI, XII, from Joplin; [XI, was almost entirely sphalerite, but analyzed to ascertain if the blendes of a given locality were more antimonial than the galenites of the same locality] ; XIII, McGee shaft, Holm'an diggings, Granby; XIV, Dade county.

XV, block mineral of remarkable purity, selected at the Eagle Furnace, Sec. 23, T. 43, B. 14 W., Cole Bounty ; XVI, Cole county, exact locality not known — collected by previous surveys; XVII, ore used at Murphy and McClurg's furnace ; XVIII, Pioneer furnace ore ; XIX, Star furnace ore; XX, Buffalo furnace; XXI, ore used at O'Brien's Scotch hearth; XXII., large crystals, from Richardson's Ozark shaft, Ozark township, Phelps county.

XXV, St. Joe Mines — with' visible admixture of chalcopyrite, pyrite and blende — contained 31.032 per cent, lead ; 5.826 per cent, silica, besides calcite, and showed distinct traces of nickel, but the amount was not estimated; XXVI, " sludge," from the washers at the St. Joe mines ; XXVII, from washers at St. Joe mines — headings ; XXVIII, from Bluff diggings,1 Mine la Motte; XXIX and XXX, washed ore from Bluff diggings, Mine la Motte, sludge and headings, respectively ; XXXI, ore used at Valle furnaces, Jefferson county ; GR— 2

18 LEAD FURNACES AND PRODUCTS.

XXXII, Jefferson county— No. XIII of the silver assay results;.

XXXIII, Perry furnace, near Potosi, Washington county; XXXIV, Hopewell furnace, Washington county; XXXV, galenite, washed from Scotch hearth residues at Hopewell furnace for re-treatment; XXXVL, from c< Seed-tick diggings," Mine la Motte tract, analyzed under my direction by W. C. Minger — sample showed chalcopyrite ;. XXXVII, ore from Mine Desloge, containing 19.675 per cent, lead by humid analysis ; XXXVIII, XXXIX, XL, dressed ores from Desloge concentrating machines, containing respectively 63.61, 76.42 and 67.96 per cent, metallic lead, estimated by fire assay, each, mean of two.

OTHER SULPHUEETED OEES.

The following species containing lead and sulphur are described by mineralogists :

ZINCKENITE (G. Rose,)

contains, by theory, sulphur, 22.1 ; antimony, 42.6 ; lead, 35.3 ;. resem- bles stibnite and bournonite, but is distinguished from these by its greater hardness and higher specific gravity.

PLAGION1TE (G. Rose,)

has the following per centage composition : sulphur, 21.3 ; antimony,, 38.2 ; lead, 40.5.

JAMESONITE (Haidinger,)

contains, theoretically, sulphur, 21.1; antimony, 32.2; lead, 43.7; iron, 3.0.

BOULANGERITE, (ThauloW.)

The percentage composition, as calculated from the formula, is a& follows : sulphur, 18.2 ; antimony, 23.1 ; lead, 58.7.

GEOCRONITE (Svanberg.)

In composition it contains, sulphur, 16.5; antimony, 16.7; lead, 66.8.

BOURNONITE (Jameson,)

has the following composition: sulphur, 19.7; antimony, 25.0 ; leady J2.4 ; copper, 12.9. None of the above species have been noticed in any of the lead deposits of Missouri. It is possible that some of the foreign metals (e. g., antimony, copper, etc.,) enumerated in the tables of analyses of galenite may be so combined and disseminated through- out the lead ores. This, however, is purely hypothetical.

LEAD FURNACES AND PRODUCTS. 19

B.— OXIDIZED OEES.

Of the oxidized ores, three mineral species only are of signifi- cance to the metallurgist, and with reference to Missouri localities * but one requires more than a passing notice.

PYROMORPHITE (Hausmann): Occurs frequently in aggregations, either botryoidal, reniform or globular; sometimes granular and fibrous; when crystallized, the forms belong to the hexagonal system, being slightly modified six-sided prisms. It has a resinous luster ; color, usually various shades of green, from a light yellowish to a deep olive. Hardness, 3.5 — 4 ; specific gravity, 6.5 — 7.12.

It consists of triplumbic phosphate and lead chloride, with 76.4 per cent, metallic lead by theory. Frequently the phosphoric acid is replaced, more or less, by arsenic acid, the lead oxide by lime, and the lead chloride by calcium fluoride.

Beautiful specimens were found at the Washington or Silver Hill mine, North Carolina, and at the Chester County and Wheatley mines, near Phoanixville, Pennsylvania. At the last-named large quantities were mined and smelted. The mineral is of very rare occurrence in the lead deposits of Missouri. When found it is usually as a coating either on galenite or cerussite. It has been noticed only in the south- western district.

ANGLEBITE (Beudant): Is also of rare occurrence, being found in the form of small, yellowish green crystals, with adamantine lust, occurring in cavities in crystals of galenite. It consists of sulphuric acid, 26.4; lead oxide, 73.6 per cent., and contains 68.3 per cent, metal- lic lead by theory.

CERUSSITE (Haidinger): The only oxidized lead ore metallurgic- ally important in Missouri. It is lead carbonate, containing, by theory :

Lead oxide 83.5 per cent.

Carbonic acid 16.5 per cent.

100.0 Metallic lead 77.5 per cent.

Its crystalline forms belong to the orthorhombic system ; occurs also granular, massive and compact; color, grayish-white, yellow, brownish-black, grayish-black and colorless ; lustre, adamantine, pass- ing to vitreous and resinous; hardness, 3.35; specific gravity, 6.47 to 6.48.

Crystallized cerussite is found abundantly at many of the mines

LEAD FURNACES AND PRODUCTS.

in the southwestern district, notably at Oronogo, Jasper county, where excellent specimens are found illustrating the change of galen- ite into cerussite.* The ores from the upper portions of the lead deposits of Dade county, show interlacing crystals of cerussite con- tained in brown iron ore or limonite.

A common form under which cerussite presents itself at many localities in all of the lead regions of the State, is as earthy, amorph- ous, compact masses of Avhite, yellow or reddish color. This form is the " drybone " of the miners. Of still more frequent occurrence is the gray or ashy variety surrounding cubical crystals of galenite or filling cavities in them. This form is the' " ash mineral" when the galenite predominates in the mixture, or the " wool mineral" when the carbonate is in excess.

The carbonate ores of the furnaces always contain some lead sul- phide and are, in reality, mixtures of cerussite and galenite. The pure or .even approximately pure cerussite is never found in quantities suf- ficiently great to warrant notable changes in the routine of treatment in the furnaces.

The following are analyses of the carbonates :

I. II.

Williams. Chauvenet.

Lead carbonate 84.0770 per cent. (Lead). 66.35 per cent.

Lead sulphide 6.2387 per cent.

Zinc oxide 2.0914 per cent. 0.75 per cent.

Antimony oxide 1095 per cent.

Copper oxide 0578 per cent.

Ferric oxide 4340 per cent. 1.51 per cent.

Insoluble matter 2.4904 per cent. 9.95 per cent

Carbonic acid 1 N f f Traces

Lime, magnesia /

Per cent, lead 65.287

No. I from Granby ; No. II also from Granby, described by the analyst as " massive ; of brownish-red color."

Cerussite in the form of stalactites has recently been found in notable quantities in a "dropped opening" or low cave, struck by a drift at the Douglass and Morgan diggings on Sec. 6, T. 25, K. 30 W., (Granby Company's property), Newton county. Mr. Thomas Richeson, the President of the Granby Company, kindly presented a specmimen, measuring nearly three inches in length and with a diameter at the base of half an inch. Some fragments were detached and were found to have a specific gravity (at 19° C.) of 6.099, determined by the flask

* See Schmidt (loc. cit. page 389) on this point. *

LEAD FURNACES AND PRODUCTS. 21

method. By analysis, the following was ascertained to be the compo- sition:

Lead carbonate 98.453 per cent.

Lime carbonate 0.259 per cent.

Magnesic carbonate 0.303 per cent.

Lead sulphate 0.107 per cent.

Ferric oxide 0.654 per cent.

Silicious matter (clay?) 0.205 per cent.

99.981

The ferric oxide occurs as mere stains or patches on the exterior of the specimen.*

C.— ASSOCIATES OF LEAD ORES— GANGUES. CALCITE (Haidinger.)

This mineral is almost the exclusive gangue of the ores in the southwestern region, and preponderates also in the deposits of the central and southeastern regions. Chemically it is lime carbonate. Its crystaline forms belong to the hexagonal system, the cleavage being eminently rhombohedral. Hardness 2.5 — 3 ; lustre, vitreous ; color ranges through a great variety of shades, from the colorless varieties to white, gray, yellow, red, brown and black.

Its most common form in the lead deposits of the State is that of a coarsely crystalline mass, generally colorless, or nearly so, and translucent. It is known among the miners as li glass tiff." Speci- mens analyzed in the laboratory of the survey show the annexed composition.

I. II.

Jefferson County. Newton County

Garvens. "Williams Mean of two analyses.

Calcic carbonate 98.680 97.962 per cent.

Magnesic carbonate .945 1.853 " "

Ferrous carbonate .047 253 ki "

Insoluble matters None None

99.672 100.068

DOLOMITE (Kirwan)

Is isomorphous with calcite and consists of lime and magnsia carbon- ates. In the southwestern deposits it is a very common gangue,

* For analysis of stalactites of cerussite from Brigham's diggings, Wisconsin, by J. D. Whitney, consult Dana, p. 701.

22 LEAD FURNACES AND PRODUCTS.

occurring either in densely crystalline masses, or loosely aggregated crystals, with curved faces, reddish brown on the surface, but color- less interiorily. The surface coloration is due to the change of fer- rous carbonate (isomorphous witji and more or less replacing calcic and magnesic carbonates in calcite and dolomite) intohydrated ferric oxide or limonite ?) Chauvenet (loo. Git. page 396) finds two speci- mens of dolomite from Joplin to have a composition as under :

I, II.

Moon Diggings. Murphy's Diggings.

Calcic carbonate 54.72 54.52

Magnesic carbonate 41.98 44.85

Ferrous carbonate 2.94 1.14

Insoluble matters 1.24 0.26

100.88 100.75

Theoretically dolomite requires,

Calcic carbonate 54.35 per cent.

Magnesic carbonate 45.65 per cent.

So that both the specimens analyzed approach very closely tjie composition calculated from the formula.

Dolomite is one form of (i soft tiff," so-called by the miners.

SIDERITE (Haidinger.)

Ferrous carbonate has not been noticed as a distinct species in any of the lead deposits. It is found replacing magnesic and calcic car- bonates, as above, and occurs also dissolved (as acid ferrous carbon- ate) in mine waters.

BARITE (Karsten?)

Commonly called heavy spar or barytes, and by the lead miners of Missouri " bald tiff," or "soft tiff," is an important gangue in the deposits of the central and southeastern regions, subordinating in abundance in these, only calcite and dolomite. It has not been recog- nized in the deposits of the southwest, though I have found it in minute amount in a mine water from Oronogo, Jasper county.

By theory, barite contains : Baryta, 65.7 per cent. ; sulphuric acid, 34.3 per cent. Two specimens of white, coarsely laminated variety, from Jefferson county, have been analyzed in this laboratory with the annexed results:

LEAD FURNACES AND PRODUCTS.

Specific gravity at 4°C

I. W. C. Minger. 4.3109

II.

J. D. Greason.

98.174

96.791

'Strontic sulphate

0 500

1 436

0 325

0.176

0191

Silica

0898

1.200

0.454

0.148

100.202 100.091

On Sec. 24, T. 36, R. 9, Phelps county, barite is found in a horizon- tal seam in mixture with galenite, and in a cave on the same section, rounded pebbles of the same mineral, coated with oxide of manganese, are found in a small stream.

SILICA AND SILICATES.

The silicious minerals noticed in association with the lead ores, are silica itself, either as quartz, (rare,) quartzite, sand or chert '(quite common); or silica in combination, as clay and calamine. The <;hert frequently contains galenite, in intercalated seams, filling small cracks, or as implanted crystals. A common form is that of a brec- ciated mass of fragments of chert, cemented by crystalline sphalerite, with small amounts of galenite intermixed. The chert passes, at times, into sand, white, or more or less colored by ferric oxide ; some- times slightly argillaceous, and occasionally impregnated with ceru- site to a small amount. At other times it changes abruptly into a microcrystalline quartzite, sometimes of a light gray color, but gen- erally of a dark brown or black color, and containing galenite and sphalerite.

Two chief varieties of clay are noticeable, and are locally distin- guished as " tallow clays," and "red tough clays." The first is unc- tuous to the touch, slightly plastic, and on exposure to the air, cracks, and finally crumbles to a greasy powder. Crystals of galenite are not uncommon in this clay. The " red tough clay " has a much higher degree of plasticity. Its color is either yellow, brownish red or deep red.

CALAMINE.

\

Or hydrous zinc silicate occurs in large quantities, in association with the lead ores, and is of great value as a zinc ore. Its features and modes of occurrence will be described when treating of the zinc ores of the State. An analysis of a specimen from Granby, made by

LEAD FURNACES AND PRODUCTS.

Mr. Christian R. Winters, under my direction, gave the following results:

I.

Silicic acid 25.243

Zincoxide not est.

Ferric oxide 1.280

Lime trace.

Water.... 7.517

II. Mean

25.735 25.480

66.813 66.813

.999 1.114

trace. trace.

7.487 7.502

100 918

Metallic zinc 53.62

D.— OTHER ASSOCIATES OF THE LEAD OKES.

LIMONITE, or the so-called brown hematite iron ore, is of general occurrence in the deposits, being a product of the alteration of pyrite or siderite. Pseudomorphs after pyrites are not uncommon.

SMITHSONITE (zinc carbonate) and metallurgically are of the most important ores of zinc, occurs very generally, but less abundantly than calamine. The lead deposits of Dade county yield large quan- tities. Two specimens from a shaft belonging to the Dade County Mining and Smelting Company, and taken at depths of twelve (I) and thirty-five feet (II) below the surface, gave in this laboratory:

I.

Pack.

Zincic carbonate 83.000

Ferrous carbonate , 1.932

Calcic carbonate 0.803

Magnesic carbonate 0.861

Ferric oxide 3.046

Alumina 2573

Silica : 7.390

Water 0.165

99.770 Metallic zinc.... .. 43.019

II.

Ohtnann, Dumesnil-

93.440 4.040 1.525 0454 0800 0.261 0.477

100.277 48.618

AZURITE and MALACHITE (basic copper carbonates) are found in small amounts at many deposits, especially at those in Morgan, Miller and Cooper counties, resulting from the oxidation of chalcopyrite.

GOSLARITE (zinc sulphate) and GYPSUM (hydrous lime sulphate) are found abundantly dissolved in the mine waters, and result from the oxidation of sphalerite and other sulphides, and from the action of free sulphuric acid thus produced, upon the lime carbonate.

LEAD FURNACES AND PRODUCTS. 25

CHALCANTHITE (copper sulphate) is also found in minute amounts in the same waters, and has a similar genesis.

BITUMEN, either in the plastic or the liquid state, is found in the mines of Jasper county, in cavities in the limestone associated with sphalerite, galenite and calcite.

The chemical analysis of the water from the mines at Oronogo,, Jasper county, is here introduced as throwing light on the genesis of the various ores and minerals found in the lead deposits of the State. The samples were collected on two consecutive days. The absence of lead sulphate is noticeable, none being detected, though careful search was made :

Analyses of Mine Water from Oronogo — Results in

grains per gallon

of 231 cubic

inches..

I.

II.

Williams.

Hare.

Sodium chloride

0.16032 grains. .18094

grains^

Sodium sulphate

0.49009

.48331

"

Potassium sulphate

0.31879

.33772

(4

Calcic sulphate

..... 27.98303

" 28 31665

"

Magnesic sulphate

2.74154

2.23635

11

Baric sulphate

0.08164

" .07115

n

Zinc sulphate ,

13.14142

" 13.08099

((•

Copper sulphate

0.01711

44 .01171

k'

Alumina sulphate

0.58649

" .69906

(t.

Calcic carbonate

4.58545

" 448954

It

Ferrous carbonate

2.29817

2.73376

"..

Manganous carbonate ,

trace.

trace.

Arsenious acid

0.11877

" .15198

'*-

Antimonous acid ,

.... 0.12232

" .13022

«•

Silicic acid

0.81645

" .64033

...

Organic matters

4.14058

3.63904

tt

Total solids 57.60315 57.18282

The copper, arsenic and antimony were obtained by the treat- ment of four litres of water, and distinct traces of Cadmium were found in the same amount. The other constituents were estimated with the amounts ordinarily used in mineral water analysis, the method of Fresenius. [Quantitative Chem. Anal., 4th English edition, page 506, et seq.,~\ being followed with such deviations as were found neces- sary from the presence of the extraordinary constituents.

GENERAL OUTLINE OF THE METALLURGY OF LEAD.

The extraction of lead from its ores is carried on in various forms of furnaces, referable, however, to three types, and giving rise to- three chief methods, distinguished as

I — The Reverberatory, or air furnace methods.

LEAD FURNACES AND PRODUCTS.

II — The Blast furnace [shaft or cupola furnace] methods.

Ill—The Hearth methods.

In the second and third methods, the chemical changes in the materials to be treated are aided by a blast of air from auxiliary blowing apparatus, while in the first the natural draught of the stack or chimney alone is relied on.

The Reverberatory and Hearth methods only find general employ- ment in Missouri. The blast furnace methods proper being employed to a limited extent in the treatment of residues (or so called slags) from the other processes (Granby, Joplin and elsewhere) or for treatment of residues and nickeliferous ores for nickel mattes and lead, as at Mine la Motte.

I — Reverberatory Treatment is applied-chiefly to high grade ores which have, as their associated gangues such minerals, the constitu- ents of which do not readily unite with lead oxide to form fusible glasses or slags, but which tend rather on the contrary, to interfere with the fusion of the oxidized lead compounds formed in the smelt- ing operations. Calcic carbonate and barite are therefore favorable gangues. The method is not usually applied to the treatment of ores with silicious gangues without the use of metallic iron as a desulph- urant, and in such cases it is commonly supplanted by the blast cupola methods as the more economical mode of extracting the lead.

Two forms of reveberatory treatment are in use :

A — The method of reaction, as it is commonly called, but more properly, tha method of air reaction, in which nearly all the lead is produced through the agency of atmospheric oxygen, a series of re- actions between various oxidized lead compounds and lead sulphide being induced. It involves two principal stages, a first, or roasting stage, in which a part of the lead sulphide is united with oxygen to form lead sulphate (FbS becoming PbSO4), or is changed into lead oxide (PbO); secondly, a reaction stage proper in which, under increased temperature, the oxygen compounds react on the unchanged sulphide, with the metallic lead and sulphurous acid as products. This stage may be better understood from the following equations commonly employed to represent the reactions taking place, though practically these reactions are much more complex than can be thus indicated:

PbSO4+PbS= 2 Pb+2SO2 or 2PbO+PbS= 3Pb-fS02.

The reverberatory furnace consists essentially of a combustion chamber (-fire box) communicating by means of an opening or flame passage with a second chamber (or hearth) in which the materials to

LEAD FURNACES AND PRODUCTS. 27

be treated are brought under the influence of the heated gases and products of combustion from the fire box. The lower part of the hearth (sole) is separated from the fire box by a dam (or fire-bridge) and is surmounted by a low flat arch, continuous with the top of the fire box, and with the opening connecting the two chambers. One or more flues, at the end of the furnace furthest from the fire box carry the products of combustion and the volatile products of the re- actions on the hearth to a stack or chimney common to several fur- naces. Various openings (OT work doors) give access to the fire box and to the hearth for purposes of introducing the charge and for manipulating it during the operations. Certain proportions between the various parts have been found best adapted to certain kinds of work, but these vary in different furnaces according to the purposes for which they are intended, and according to local condition, such as character of fuel and ore. Commonly, however, the length of the grate bars of the fire box is equal to the breadth of the hearth. The length of the hearth is from 1 to 2.5 times the breadth, and the height of the arch above the fire-bridge is usually from one-third to one-half that of the arch above the sole.*

The reverberatory reaction method has been variously modified in so far as the arrangement of the parts of the furnace and the details of operations are concerned, but three chief systems of con- ducting it are recognized and named from localities, furnishing typical examples. These three systems are:

a— The Carinthian.

b — The Flintshire or English, and

c— The French.

In all processes there remain on the sole of the reverberatory materials rich in lead, which give rise to a stage of treatment addi- tional to the two already mentioned, having for its object the recovery of a further amount of lead. The features in conducting the rever- beratory reaction method become, therefore, as follows:

first stage— period of oxidation. The ore to be treated is spread over the sole of the reverberatory and gradually brought to a low red heat. The charge is stirred in order that the oxidation may be as uniform as practicable, and the temperature is so controlled that the materials being treated may not be agglomerated or fused — conditions which would seriously operate against oxidation. During this period, lead oxide and lead sulphate are produced. The duration of the operation varys according to the arrangements of the furnace, and

* On these points consult Havrez, quoted in supplement to Crookes & Kohrig's translation of Kerl's Metallurgy.

28 LEAD FURNACES AND PRODUCTS.

according to the weight and grade of the charge. The presence of carbonate or other oxidized lead ores in greater or less amounts pro- portionally shortens the time required for oxidation. Under all cir- cumstances the oxidation period is brought to a close before all the lead sulphide is changed. With regard to the time required, experi- ence alone can determine for each special instance ; in general, it may be stated that the time necessary for the first stage in the treat- ment of 450 Ibs. of 65 to 72 per cent, galena ores with soft wood fuel at Bleiberg (Carinthia) was three hours, while in the English furnaces from 16 cwt. to 1 ton of 70 to 75 per cent, ore requires two hours (for -first firing) with coal as fuel.

SECOND STAGE OR DEOXIDIZING PERIOD: The atmosphere in the furnace is rendered less oxidizing and the roasted materials are brought rapidly to a cherry-red heat. At about this temperature the reactions between the lead sulphate (or lead oxide) and the unchanged lead sulphide begin, resulting in the production of metallic lead and sulphurous acid. The lead runs down over the sole of the furnace and collects in a basin or sump in the sole, and is tapped thence into a kettle exterior to the furnace (Flintshire), or runs directly as reduced into the exterior iron kettle (Bleiberg-Oarinthian). The residues of the Flintshire furnace are either pasty and are raked out (gray or drawn-slag) or in certain cases are melted and tapped, (run- slag) and are passed to other treatment; those from the Bleiberg are pasty and are treated in the same furnace.

During this stage frequent manipulations of the charge are neces- sary in order to bring about intimate contact of the lead sulphate (or oxide) and the lead sulphide. The operation is terminated when the lead ceases to flow. The temperature of the furnace is then somewhat lowered, and a roasting (or first stage) again brought about, and then again a second period, thus alternating the roastings and reactions, as long as lead flows and the residues have not passed into a state of liquid fusion. The length of time necessary is largely influenced by the care and skill of the workmen in the first or roasting stage.

The French method is different, in so far that the roasting stage is prolonged until the roasted mass is caked together, and drops of lead appear, and the second or deoxidizing period is characterized by the introduction of carbonaceous matters (wood and coal slack). The lead is collected in a sump. The process is adapted to ores more highly silicious than are usually deemed suitable for being worked by either the Bleiberg or the Flintshire method ; but the consumption of fuel is greater, the yield is smaller, and the loss of lead greater.*

^Percy's Metallurgy of Lead, page 245 ; Crookes & Rohrig (KerVs) Metallurgy, page 58.

LEAD FURNACES AND PRODUCTS. 29

THIRD OR SUPPLEMENTARY STAGE: The matters remaining on the sole of the furnace after the repetitions of the two proper stages, are still rich in lead, existing as oxide, sulphate, silicate and sulphide, but in such forms of combination or in such physical condition that further reactions among themselves are not possible by a continuance of the ordinary operation. To restore the physical condition necessary for the reactions between the lead sulphate and sulphide, and to reduce the oxidized compounds to the condition of metallic lead, lime or charcoal is introduced into the residue and the temperature of the furnace is raised. Charcoal is oxidized at the expense of a part of the oxygen lead compounds producing carbonic acid, which, escaping through the materials, renders them more porous and induces a condi- tion favorable for further reaction between the remaining oxidized lead compounds and the lead sulphide. Lime acts mechanically, ren- dering the materials less fusible and more spongy, thereby allowing further reactions as above. There is also a possible chemical action of the lime, but on this point metallurgists are at variance.

The choice between charcoal and lime as reagents in the third period is influenced chiefly by the manner in which the roastings and reactions have been carried on, but is limited also by the fact of the ores being argentiferous or non-argentiferous — for silver bearing ores lime being preferable as rendering a cleaner slag, that is, one freer from silver. In the English furnaces lime is most commonly em- ployed, while at Bleiberg the residues of two charges are treated with charcoal (pressing), resulting in the production of less pure lead (press lead — Pressblei).

As will be seen in the section devoted to the details of air-fur- naces throughout this State, the supplementary stage is rarely resorted to. This is manifestly advantageous, so far as the production of a uniformly good quality of lead is concerned, but in all other respects is wasteful, and therefore to be condemned. At present the abundance of high grade ores may perhaps palliate this want of economy, but the treatment of these rich residues in the reverberatory must even- tually become part of the method.

The residues from the reverberatory are, when rich enough, passed to treatment in slag furnaces by methods which are of the type of the blast or cupola furnaces, and will be comprehended from the descriptions given of these on subsequent pages. The Missouri fur- naces, as before noted, usually disregard these residues. Occasion- ally, however, when conditions of transportation are favorable, they are sold to some of the lew more complete establishments at which slag furnaces are run, and are there treated for a special brand or

30 LEAD FURNACES AND PRODUCTS.

slag lead. Analyses of these residues will be found in the section in which the details of the air furnaces are given. Annexed are analyses of Flintshire Gray Slag for comparison :*

Per cent. Per cent

Lead sulphide 0.90

Lead sulphate 9.85 18. 7S

Lead oxide 48.87 38.08

Zinc oxide 7.52 12.00-

Lime 12.68 13.50

Alumina 3.01 0.71

Ferric oxide 2.86 Ferrous oxide.. 3.89-

Silicic acid (combined) 12.52 12.32

Kesidue.... , 0.92

99.66 99.23

Metallic lead 52.88 48.142

In addition to lead in the residues, there is a further source of loss of metal, arising from the volatility of lead and its compounds. This loss is inherent in all methods of lead separation, but varies greatly in degree in the different forms of treatment. At well arranged estab- lishments means are provided for the condensation or collection of this volatilized lead matter or fume, by the introduction of a series of condensing chambers or other apparatus between the furnace and the stack; but these methods have not become of general use in this State where abundant and high grade ores and cheap raw fuel, coupled perhaps, with a laudable desire on the part of the smelter to produce an uniform grade of soft lead, have diverted attention from these appa- rently minor, but, in reality, important adjuncts to economical smelt- ing and to the sanitary condition of operatives as well as of a neigh- borhood.

The composition of lead fume will be seen from the annexed analyses, I, being fume from the reverberatory at Granby, Newton county, by myself, and II, from reverberatory at Pontgibaud, by

Rivot :

I. II.

Lead sulphate 76.750 39.00

Lead sulphide 188 4.50

Lead carbonate 6189 35.00

Lead oxide 8.371 Zinc oxide... 2.70

Ferric oxide 1.147

Antimony oxide 903

Arsenious oxide trace. 1.50

Zinc chloride 049

Zinc sulphate 1.675 2.30

* Percy " Metallurgy— Lead," pages 235 and 239.

LEAD FURNACES AND PRODUCTS. 31

I. II.

Cadmium sulphate trace.

Calcic sulphate 923

Magnesic sulphate 660

Insoluble residue 2.510 Silica and clay ..13.20

99.365 98.20-

Percent, metallic lead 65.156 58.253

Per cent, metallic zinc 0.676 3.09

The composition of the fume and its amount are, of course, largely influenced by the composition of the ore and the character of the treatment which the latter receives. The quantity is much greater than is realized by our smelters, being fully five per cent, of the fire assay value of the lead contained in the ore. Eilers, in a paper on the avoidable y/aste at American Lead Smelting Works,* estimates that the loss by fume and dust at the Utah Smelting Works, averages iully nine per cent, of the value of the original contents of the ore.

In the reverberatory air-reaction method, the presence of small amounts of blende — not exceeding twelve or fifteen per cent, of the charge— is regarded as advantageous, since it renders the mass, after oxidation, less fusible, and in better condition for frequent alterna- tions of oxidations and deoxidations. On the other hand the presence of blende is disadvantageous, because it increases the loss of lead by volatilization, the specifically light zinc oxide which is produced in the roasting, assisting in carrying mechanically the denser lead com- pounds out from the furnace. The action of the zinc oxide in this direction may be inferred from the fact that zinc white or oxide, as produced directly from the ores is in such condition that an ordinary flour barrel will contain only from thirty to thirty-five pounds of the material.

If the ores are argentiferous, the loss of silver is greatly increased through similar action of zinc compounds.

The experiments of Malaguti and Durocher,* made with argen- tiferous zinc blende, indicate that the loss of silver in the presence of zinc compounds may be very considerable, reaching as much even as 70 per cent, of the original contents of the ore, but ranging usually between 15 and 60 per cent, according to the richness of ore in silver and zinc, and according to the management of the furnaces. f

Pyrite in the ore is beneficial in the first stage, aiding in the con-

* Ti^ansactions Am. Inst. Mining Engineers, Vol. III., pp, 98, et seq.

* Annales des Mines, XVII, 1850.

fin Journal of Franklin Institute, Feb., 1871, this matter has been discussed at some length by the writer of this report.

32 LEAD FURNACES AND PRODUCTS.

version of lead sulphide into lead sulphate and oxide. In the second stage, the iron oxide, formed by the oxidation of the pyrite, makes the charge less fusible, while any unoxidized pyrite decomposes lead sulphate, aiding in the separation of metallic lead. An excessive amount tends to the formation of matte, and thereby to loss of lead. If the pyrite is arsenical, the quality of the lead is impaired by the presence of arsenic. Ohalcopyrite acts in a manner analogous to that indicated for pyrite, though smaller amounts work more injuriously than are required for the latter, since matte will be formed, and the quality of the lead will be injuriously affected by the presence of copper. Stibnite, and other antimonial minerals, even in small amounts (2 — 3 per cent.) are objectionable, causing caking of the charge, increased loss of lead and silver by volatilization, and impure lead.

Oalcite, barite, siderite and fluorite (fluor spar), within certain limits, are either beneficial or not objectionable. Quartz, clay and other silicates in small amounts (1 — 6 per cent.) make a fusible charge preventing good roasting and interfering with the reactions.

In cases TRihere argentiferous ores are treated, the lead produced in the earlier parts of the processes is richer than that of the later periods, as silver sulphide is more readily decomposed than lead sul- phide.

B — Method of de&ulphurization and precipitation l>y metallic iron : This method is very limited in its application. It may be employed with silicious ores,* unsuited to method A, but has been largely replaced by blast furnace methods in the treatment of such ores.

The reaction, in theory, is represented by the equation :

Pb S + Fe. = Fe S + Pb.

In practice, three products (besides fume) are formed : slag, matte (iron sulphide with some lead sulphide) and lead. The amount of iron added never exceeds 35 per cent, of the weight of the charge. The operations are carried on in reverberatories of smaller dimensions than those used for method A, so that higher temperature may be obtained. The sole of the reverberatory is arranged with a sump, in which the three chief products collect in the order of their gravities, and are thence drawn off through the tap hole.

The method is expensive in fuel, labor, tools, and in the iron for the desulphurant. When argentiferous ores are treated there are

* Kerl's Handbuch der Metallurgischen Huttenkunde, Vol. II, p. 89.

LEAD FURNACES AND PRODUCTS. 33

produced rich mattes and slags which require treatment in the blast furnace. The advantages it possesses over the blast furnace methods are found in the comparatively small cost of the furnace plant, and in the fact that raw fuel can be used.

II— BLAST FURNACE METHODS.

These are of very general utility and comprehend a great variety of details in furnace arrangements and in the manner of conducting the operations. In general the furnace is an upright shaft into which the materials subjected to treatment are charged along with the fuel {charcoal or coke) and into which is forced a current of air from one or more tuyeres. Formerly the furnaces were of rectangular section, somewhat pyramidal in elevation, narrowing toward the top and gen- erally with a single tuyere. Within a few years radical changes have been made in the shape of the furnaces ; the size has been greatly in- creased and the number of tuyeres has been multiplied. The im- proved lead-blast furnaces are in form of an inverted truncated cone, or an inverted truncated pyramid with a rectangular horizontal section with tuyeres on both the long sides, or with a hexagonal or octagonal section and tuyeres on all sides. With these changes have come in- creased effectivness of fuel and other important economical consider- ations. In all cases, whether the old forms or the improved forms be used, the cost of establishment is much more expensive than for the reverberatories. Nevertheless, for argentiferous ores, or for ores poor in both silver and lead> but with silicious gangues that cannot be sepa- rated by mechanical means, the blast furnaces or cupola processes are of great value, and necessarily of wide application. An extended range of modifications, the results of local experience with regard to the character of the ores and the available fuel, are to be observed in these methods, but they may be generally referred to two types of treatment :

A. — Direct fusion of the raw ore with iron as a desulphurant. (Niederscldagsarbeit?)

B. — Treatment of previously roasted ore with or without the ad- dition of metallic iron. (Roeat- Reductions- Arbeit.)

Method A is adapted to rich lead ores containing little silver, and only small amount of foreign sulphides, but associated with silicious gangues. Foreign sulphides make the mattes richer in lead and silver, or increase loss by volatilization, or make the charge of diffi- cult fusion or finally impair the quality of the lead, this last not essen- tially peculiar to this method. Low grade ores require cheap iron

GR— 3

34 LEAD FUKNACES AND PRODUCTS.

and relatively high market rates for lead. Within certain limits, the higher the temperature the more complete the decomposition of the lead sulphide by the iron, and less lead sulphide unites with the ferrous sulphide in the matte. A certain quantity of slag-forming matters is necessary, as slag is required to prevent oxidation of lead in the furnace hearth, but the slag must be a fusible one to avoid in- creased consumption of fuel and greater loss by volatilization ; at the same time it must not form at a temperature lower than that re- quired for the desulphurization of the galenite and for the formation of mattes with the practicable minimum of lead.

Allowing cast iron to contain five per cent, of impurities, it will be found that one part of such iron will extract 3.64 parts of lead if ferrous sulphide (Fe S) is formed. Usually di-ferrous sulphide (Fe2S) is produced. Less iron is necessary when the ores contain chalcopyrite and blende, and is also desirable to avoid decomposition of these sulphides. An increased amount of the iron is required when the ores are sensibly arsenical. Increased amount is prejudical towards the silver sulphide, throwing it into the matte.*

Method B. Ores containing so much foreign sulphides as to be unfitted for method A, or so rich in silicious gangues as to be unadapted to the reverberatory reaction ; or argentiferous ores which cannot be concentrated mechanically without loss of silver, are suitable for treatment by this method. In some of its many modifications it is suited to a great majority of cases, especially in the treatment of the lead and silver bearing ores of Utah, Nevada and Colorado. The pre- liminary roasting does away largely with the use of iron, and is per- formed generally in reverberatories and is finished by raising the temperature sufficiently to agglomerate the roasted mass or better to fuse it. Basic ores containing much lime, etc., are better scorified by the addition of silica. Neutral ores, or those which contain in themselves the slag-forming constituents in the proper proportions, require no fluxes in the cupola, but acid ores or those containing quartz or silicious matter are fluxed by ferric oxide or by lime. Fre- quently a small amount of scrap iron or of forge scale is added to de- sulphurize any galena which may have escaped oxidation during the roasting. Production of matte is avoided as much as possible, un- less the ores are notably copper-bearing and the saving of that metal is an object. The chief products, besides fume, are slag and lead.

*For illustrations of this process consult Kerl loc. tit., pages 135 et. seg, or Crookes and Kohrigs, translation, pages 98 et. seq ; also Klvot Metallurgie du Plomb et de V Argent, page 450. Further particulars would encumber this report unnecessarily.

LEAD FURNACES AND PRODUCTS. 35

The slags are compounds of silica (from the ores or from addition of acid fluxes) with lime, ferrous oxide and a small amount of lead oxide — the lime or iron oxide being added when necessary (in the case of acid ores) to take the place of the lead oxide in the slag, and prevent loss of lead. The most desirable slag is that which is either a singulo silicate (the oxygen of the bases : oxygen of the acid=l:l), or mixtures of a singulo silicate with a bisilicate (in which, oxygen of base: oxygen of acid=l:2). The singulo silicates are liable to enclose particles of metallic lead and thereby cause loss of metal; the bisili- cates are not open to this objection, but require higher temperature for their formation, and are therefore more expensive in fuel, and cause greater loss by volatilization and greater reduction of foreign oxides. The bisilicates do not act so strongly on the furnace lining.

As noted above, the formation of matte is avoided and this consti- tutes one of the advantages of the preliminary roasting. When, how- ever, it is necessarily produced, as in the case of silver and copper bearing ores, it is returned to the furnace or is treated by more elabo- rate processes for the separation of the valuable metals. In Utah and Nevada it is usually disregarded.

The proper fuel is charcoal or coke, or a mixture. The latter gives the best yield of metal; charcoal gives a lower heat, but one more uniformly distributed over a larger space than that of coke, which furnishes higher heat in a small space near the tuyeres. Besides providing under the influence of the blast the temperature necessary for the chemical changes and slag fusion, the carbon of the fuel is a deoxidizing agent for the lead compounds in the roasted ore. The carbon also reduces iron oxide, and the metallic iron thus formed is a desulphurant for lead sulphide that may be present. Excessive reduc- tion of iron is to be avoided, for iron deposits are then formed in the hearth of the furnace, (sows, bears, etc.) Low cupola furnaces are best in this respect; high furnaces are more economical of fuel and avoid so great a loss of lead in fume.

The lead and slag (and matte when formed), are drawn off at inter- vals at the breast of the furnace by the ordinary process of tapping, or by means of the mechanical device of the syphon tap.

This form of treatment not being required for the Missouri ores, excepting in one instance, and offering no advantages over the rever- beratory method so far as this State is concerned, it has not been con- sidered necessary in this connection to dwell at any length on the cupola methods, nor, in fact, to give anything more than such an out- line as is necessary to an intelligent comprehension of the subject of the metallurgy of lead. Those interested in it will find ample illus-

LEAD FURNACES AND PRODUCTS.

trations in the works of Kerl and Rivot, before quoted, and, for the more improved furnaces, in the reports of United States Commissioner Raymond, (especially for 1872, page 379; an excellent resum6 of the subject adapted to the non-professional reader, and instructive to the professional metallurgist), in transaction American Institute of Min- ing Engineers, and in Church's Notes of A Metallurgical Journey in Europe.

Ill— HEARTH METHOD.

Hearth treatment is in fact an air re-action method, in kind like that described for the reverberatory, but with the difference that the oxidation and reduction go on simultaneously under the influence of a blast of air. Lead sulphate and lead oxide are produced by the air thrown in through the tuyeres, and act, at once, on the lead sulphide.

The Scotch-hearth has been replaced in this country by a modi- fied apparatus generally known as the American-hearth. The latest, used in Missouri, is the American water-back hearth of somewhat larger size and with three tuyeres instead of one in the older form- The upper part is formed on three sides by a double- walled box of cast iron, technically known as the tuyere-plate, through which passes three tuyeres. A circulation of water is maintained through this iron box, and serves the double purpose of protecting the tuyeres and the castings. Back of the tuyere-plate is the wind box which receives the blast from the blowing apparatus. The hearth bottom or box is also of cast iron set in masonry which carries the upper iron parts of the hearth. The hearth-box contains the molten lead or lead bath upon which the charge floats and upon which the operations of smelt- ing are performed. The work stone or table, also of cast iron, slopes downwards and forwards from the front top of the hearth-box toward the iron pot into which the lead from the reduced ore passes and accumulates. This pot is built over a small fire place, the fire in which keeps the lead in a fluid condition for ladling into the moulds. The apparatus is surmounted with a hood for carrying off the fumes and the products of combustion.

The walls of the tuyere-plate are commonly about one and a half inches thickness. The nozzles of the tuyeres through which the blast reaches the charges, are from one to one and a half inches in diame- ter. The tuyeres enter through the back wall of the hearth at a height of from one three inches above the surface of the lead-bath contained in the box and constituting as before stated, the sole upon which the

LEAD FURNACES AND PRODUCTS. 37

charges are worked.* They are about six inches apart from each other, and the two outer ones of the system are about the same dis- tance from their respective sides, so that the back of the tuyere-plate is usually about 23 inches. Its height is 16 inches. The sides are 1 foot 10| inches from back to front, for the inside walls, and 2 feet 5£ inches for the outside walls. From inner to outer wall, outside meas- urement, 7-J inches ; space between walls, 4-J- inches.

The hearth is operated by first kindling a wood fire upon the sur- face of the lead in the hearth box ; on this fine charcoal is thrown, well ignited and the blast turned on. Some residues or so-called slags, from the previous smelting are thrown on this fire, and, as soon as the lead in the bath is properly melted, the galena ore, crushed to the size of a pea. is thrown on in charges of about twenty pounds at a time. A little caustic lime is added as a flux, the mass covered with fresh charcoa|. and the whole allowed to remain undisturbed for about five minutes. At the end of this time, thorough contact of charcoal and ore is brought about by continual stirring accompanied by break- ing so that the blast may have passage and full oxidizing effect. These manipulations are continued for some fifteen minutes when a new charge of twenty pounds of ore is added. Lead soon begins to flow over the inclined work-table into the kettle whence it is ladled or run by syphon into the moulds.

A shift of eight hours will treat about 3000 pounds high grade ore, yielding by the work, about 68 per cent, of metallic lead, and requires two workmen. At the end of this time the metallic bath is cleared of residue for the next shift; the so-called slags are sorted and that which is rich enough is crushed and washed for separate treatment in the same hearth, yielding about 30 per cent. lead. The poor residues and the residue from the treatment of the rich slag are either disregarded, or in a few cases, passed to further treatment in the slag furnace. About thirteen bushels charcoal ore used per shaft or for the treat- ment of 3000 pounds of ore. Both ore and charcoal are delivered by laborers to the smelters, and as the laborers can readily serve sev- eral hearths, a reduction of cost of working is always effected by having a number of hearths side by side.

Under the conditions surrounding these operations, there is

* "It may be asked why should the contents of the ore hearth be kept floating on the melted lead? The answer is thai: if the bottom were formed of brick or other solid refractory material, inconvenience might be caused by accretion of slaggy matter, whereby the level would be changed and the working of the furnace deranged. A bottom of iron would be rapidly acted upon. Let the reader try to suggest a substi- tute for the simple and usual hearth-box filled with molten lead, and he will probably be puzzled." Percy, Metallurgy of Lead, 289.

38 LEAD FURNACES AND PRODUCTS.

necessarily a considerable loss of lead by volatilization. The scoria- ceous character of the residue make it also rich in unchanged ore and shot lead. The hearths require, therefore, high grade ores, and have the further disadvantage of being a costly form of apparatus. On the other hand, they will treat a much greater amount of galena in a given time than will the usual reverberatories in the same time. With a single American-Scotch hearth the cost of production of 1000 pounds of lead is about $ 5, and for the production of the same amount from a reverberatory under equal conditions, the expense is $4.90 inde- pendently in each case of the cost of the plant. By increase of number of hearths, the expenses of operating are decreased much more rapidly than by an increase in the number of reverberatories. There are few details from which calculation can be made of the amount of loss by volatilization in the hearth methods in this coun- try. In 1849 an experimental ore hearth, similar in principle to that formerly worked at the Rossie (New York) Lead Mines, and in which wood was used for fuel, was erected at Bleiberg, in Carinthia, and during that year and the years 1850 and 1851, the following results in regard to the loss, other than that caused by the slag, were obtained :*

Average per cent. Per centage loss

lead in ore. of lead, exclusive

Year. of slag.

1849 71.52 10.42

1850 71.70 9.74

1851 70.27 11.38

The slag from the hearth cannot be homogeneous ; analyses will be found in the part of this report given to the illustrations of the Missouri hearth furnaces. The following is Plattner's analysis of the slag produced in the above experiments at Bleiberg :

Sil ica 5.260 per cent.

Sulphuric acid 5.038 per cent.

Lead oxide 37.710 percent.

Ferric oxide 19.500 per cent.

Zinc oxide 19.200 per cent

Molybdic acid 0.460 per cent.

Lime 8.856 per cent.

Magnesia and manganous oxide 1.417 per cent.

Alumina with traces potash, soda and copper oxide 1.760 per cent.

99.201

At Przibram, Bohemia, the American hearth was tried with ore yielding, by assay, 74.88 per cent, lead ; the yield, by the treatment,

*Percy, Metallurgy of Lead, page 292.

LEAD FURNACES AND PRODUCTS.

was 60.88 per cent., not including the lead subsequently extracted from the slag: the slag amounted to 45.94 per cent, of the ore put in treatment. The reported produce of the residue is enormous when compared with the experiences in this country.

PURIFICATION OF LEAD.

The purity of the resulting lead, whatever the process employed in its production, depends, as before mentioned, largely on the purity of the ore smelted. In cases where argentiferous ores have been run through any of the methods the work lead produced is refined when necessary, and the silver, if small in amount but still great enough to be extracted, concentrated (Pattisonized) and finally separated from the lead by cupellation, or by treatment with zinc and subse- quent separation of the zinc and silver and purification of the desil- verized lead. Even when not sufficiently rich in silver to warrant attempt at separation of the two metals, the lead in most cases re- quires refining, improving or softening. The object of these prac- tices is to remove or to lessen the amount of the foreign metals, cop- per, zinc, iron, antimony, arsenic, nickel and bismuth, which render the lead hard and sonorous and unfit for many of its industrial applications.

Arsenic, antimony, bismuth and copper are the most objectiona- ble, the first two being prejudicial in almost all uses (excepting for special alloys as shot metal and type metal), but are more so towards the use of lead for mechanical purposes than for white lead manu- facture ; the reverse is true in general for copper, for it is not so ob- jectionable in lead intended for mechanical purposes as for corrosion into white lead. Zinc rarely exists in serious amounts ; one and a half being the highest per centage of this metal possible in lead* ; iron in notable quantities, passes into the lead only when the latter has remained in a melted condition in contact with iron.

The methods of softening in common use are :

a — By process of atmospheric oxidation, the lead being melted and oxidized on the surface, the oxidation of a part of the lead induc- ing a more rapid and more thorough oxidation of most of the foreign metals, especially of antimony. The dross which is formed is re- moved, a fresh surface oxidized and these operations repeated until the lead has reached the required degree of softness. The time re- quired, and consequently the proportion of lead oxidized depends on the quality of lead, on the temperature and on the amount of surface of melted lead exposed to the air. The operation may be carried on

^According to Mathiessen and von Bosse.

40 LEAD FURNACES AND PRODUCTS.

either in a common reverberatory, or in one in which the ordinary sole has been replaced by an iron pan, or in one into which an artifi- cial blast or current of air is driven. [At Pontgibaud, where a cast iron bottom was used, the charge was about 20 tons hard lead, the time required was three days (including charging and discharging the furnace), and the amount of soft lead produced was 94.7 per cent, of the original lead.*] According to Kichardsonf the results of treat- ment of " many hundreds of tons of hard lead," gave the annexed results :

Good Spanish hard lead 93.2 per cent, soft lead.

Hard lead from crystalized dross 90.3 per cent, soft lead.

English slag lead 87.1 per cent, soft lead.

Slag lead from Spanish dross 66.9 per cent, soft lead.

Slag lead from refase products 67.3 per cent, soft lead.

Chinese. tea lead (containing tin) 76.4 per cent, soft lead.

5 — By a process of oxidation brought about by the addition of oxidizing agents. [Baker's method, with acid sodic sulphate and sodic or potassic nitrate ; nitre, soda ash and lime in method of Pontifex &r Glassford. In this latter the mixtures recommended are, 3 parts sodic nitrate, 4 parts soda ash, and 4 parts of burned lime for lead containing from 5 to 15 per cent, antimony; and equal parts of each reagent in cases of lead with less than 5 per cent, antimony. The furnace employed is the ordinary calcining pan-furnace, and about 55 Ibs. of the mixture are required for 9 or 10 tons of the lead for & twenty-four hour's operation.]

c — By skimming with boards (England), or with iron scrapers (Germany), the dross which forms on melted lead. [Applicable to the purer leads, containing little copper.]

d— Poling or stirring the melted lead with a stick of green wood. [Applicable to rather pure leads, removing largely the antimony and copper at a great saving in labor, time, fuel and lead over the rever- beratory methods of working.] This method is of very general ap- plication throughout Missouri, the leads being produced from pure ores by either the reverberatory or hearth furnaces. It is also used on slag leads which are not so pure as leads produced directly from the ores. (See results of analyses of Missouri leads tabulated in chapter III.)

The dross which is incidental to these or other processes of soft- ening may be treated by various methods (preferably in cupola fur- naces), producing an impure or hard lead, which is either sold as such

^Phillips Mining and Metallurgy of Gold and Silver, pp. 482, et seq.

f Watt's Diet, of Chemistry— Art.— Lead by Richardson, Vol. Ill, p, 518.

LEAD FURNACES AND PRODUCTS. 41

or purified, and slag. At the furnaces in this State the dross is either disregarded or passed to treatment with residues, or, without consid- eration of the effect on the lead, occasionally returned and treated with original ore.

The treatment of slags or residues more properly belongs to a class of blast or shaft furnace methods — the common form of appa- ratus being a low shaft with a simgle tuyere being of the type known as Krumofen. The method as modified at the Missouri fur- naces is described at some length in the chapter devoted to the illus- trations furnished by the furnaces of this State. In general terms it consists of the reduction of the lead compounds through the action of carbon either as coke or charcoal, saving as much lead as is prac- ticable, but the greater part remaining in combination with the silica as a true slag. The substitution of a cheap base (lime or iron oxide) for the lead oxide in the slags and the recovery of the greater part of the lead is not attempted as in the shaft furnace methods proper.

There are economical considerations in favor of this wastage of lead under the conditions which attend lead smelting in this State, and the pecuniary loss by it is, perhaps, more apparent than real.

In consequence of the fact that the residues contain a consider- able concentration of some of the foreign metals of the ore, and as a further consequent of the inherent features of shaft furnace methods, slag leads are always harder than these produced from the ore di- rectly either by the reverberatory or the hearth treatment. They are softened or refined, to some degree, by partial oxidation in the rever- beratories, according to the plan above given. They do not give- results as satisfactory when used for chemical purposes, such as for corrosion into white lead, but for many mechanical purposes they serve equally well.

CHAPTER II.

ILLUSTRATIONS OF LEAD SMELTING IN MISSOURI.

The illustrations of the lead smelting operations which we have been able to collect comprehend data from most of the establish- ments in the State. They include in general, details of the form and size of the furnaces; weight of charge and time of elaboration; con- sumption of fuel and necessary amount of labor. The pecuniary out- lay, whether necessary for the establishment of the works or for the cost of treatment, has not been entered upon; nor would such a course have been desirable or of any benefit when comparison will have to be made of the results reached by the different furnaces. In fact such a course would tend rather to confuse and to give erroneous ideas, since it could not reach entire accuracy.

The result obtained by the several furnaces have been illustrated by a full line of chemical work, including analyses of the various products. The ores have not been assayed to determine their value in lead, because average samples could not be obtained, and results of specimens would have been more than useless. *No estimations, by chemical processes, of the value of the ore put in treatment, are made at the furnaces.

The reverberatory treatment will be first considered and subse- quently that of the ore-hearths. The section on slag treatment in- cludes nearly all the establishments at which it is practiced. It will be found of interest, in view of the great mystery with which it has been surrounded by the lead smelters of the State.

REVERBERATORY METHOD IN MISSOURI.

SOUTHWESTERN LEAD DISTRICT— (I). The Granby Mining and -Smelting Companies chief establishment is situated at Granby, New- ton county, at a distance of one and three-fourths miles from Granby Station, Atlantic and Pacific Railroad. A switch -road connects the station and furnaces.

The ores are furnished by the Granby mines in the vicinity of the furnaces, as well as by various diggings at Joplin and Oronogo, in Jas- per county, and are usually bought from individuals working, on leases, the lands of company. Preparations are, however, being made to

LEAD FURNACES AND PRODUCTS. 43

smelt at Joplin and at Oronogo the ores from the company's estate in the vicinity of these places, a plan which in its realization must be of great benefit on the score of economy.

The preliminary operations of crushing are done by a Blake's breaker and a pair of smooth faced rolls. The concentrating machinery for such ores as require it, consists of an eccentric jig, a Oaz- in's patent one plunger and a sliding lever jig.

The furnaces include, besides six hearths, and two furnaces for slag treatment, fourreverberatories of which two'are of the ordinary pattern in use throughout the State (the common air furnace), the remaining two being larger and modelled on the plan of the English or Flintshire lead furnaces. The latter have been in operation within the last two years, and are of the first of the pattern started in the State, as far as can be ascertained.

(a) Flintshire Practice: The hearths are 10 feet long by &J- feet width ; the soles being formed from slag from the furnaces well agglomerated by strong heating, and shaped into the ordinary sump near the middle door on the front or working side of the furnace. The bridge is one foot in height above the sole at that point. The fire-box is five feet long by three feet wide. The charging is done through the common hopper arrangement in the arch at a point oppo- site the work door nearest the fire bridge ; the charge is manipulated through the six work doors, three on each side. The tap hole opens from the sump, though the wall of the furnace below the middle door on the front side and connects with the exterior iron kettle from which the lead is ladled into moulds.

The furnaces run on a great variety of ores, of which no valuation is made by preliminary assays. The weights of the charges are, therefore, very variable. For "number one block" mineral it is generally about 1500 pounds worked off in twelve hours; for "number one wash mineral," the same amount elaborated in about fourteen hours; for carbonate or "dry bone" mineral, one thousand pounds in six hours, and for achats," (i. <?., galenite on chert or dolomite, which is calcined at a low heat to make the rock more easily broken by hand, preparatory to hand sorting or rough washing), 1000 pounds worked in ten hours.

The charge is spread over the sole and the roasting done at a low temperature, the time rarely exceeding two hours, or till the charge begins to agglomerate. When the roasting is deemed finished the fire is urged and the lead runs into the sump, the tap hole being closed with a plug of lime. When the charge has been No. 1 block mineral, the tapping is done at the end of ten and a half hours after charging. Before tapping, the matters on the hearth are thickened

44 LEAD FURNACES AND PRODUCTS.

by the addition of wood ashes and charcoal and filled up around the sides of the sole, to allow the lead to drain into the sump. After well draining the plug of the tap hole is withdrawn and the lead runs into the kettle, where it is polled and then ladled into the moulds.

After tapping the fire is urged so that more lead may be drained from the residues. This metal is tapped from the sump as before ; the residue or gray slag is drawn, the sole of the furnace is repaired, if necessary, and a fresh charge is introduced.

Two hands are required at a furnace, working shifts of twelve hours in the winter season or eight hours during the summer. Each furnace consumes six cords of wood during twenty-four hours, or forty-two cords per week, representing the treatment of 35,000 pounds of average mineral, with a furnace yield of about sixty-six per cent, or 23,000 pounds polled lead. The amount of wood required is there- fore 2,4 cords per ton of 2000 pounds of mineral; the labor for the same amount of ore is two days (with average postes).

The so-caljed slags or residues are passed to the slag-furnace for further treatment, but, as they do not receive there a separate opera- tion, but are run in mixture with the residues from the other rever- beratories and.the hearths, it is impossible to learn anything respecting their yield of metallic lead, nor of their quantity produced from a given weight of charge. They are not homogeneous, so that chemi- cal analyses will show a varying per centage of lead. A specimen representing the residue from a run of block mineral in the furnace,, gave by mechanical separation, 1.02 per cent, of mechanically enclosed or " shot" lead, and after the removal of this the residue showed the following result on chemical analysis — the lead sulphate being deter- mined in this as well as in all other analyses of slags, by solution m sodium hyposulphite :

Silica 12.557 per cent.

Lime 0.642 percent.

Magnesia trace

Ferric oxide 3 220 per cent.

Alumina * 0.642 per cent.

Antimony oxide 0.170 per cent.

Zinc oxide 2.264 per cent.

Lead sulphate 2.509 per cent.

Lead sulphide - 22,084 per cent.

Lead oxide, by difference 55.939 percent.

100.000

A direct determination of the metallic lead, by humid analysis, gave, including the mechanically enclosed metal, 73.703 per cent. A comparison of this result with that of Percy's analysis of the gray slag

LEAD FURNACES AND PRODUCTS. . 45

from the furnace near Holywell, Flintshire, cited in the preceding chapter, (page 80), and the large amount of unchanged sulphide (22 per cent.) would seem to warrant the conclusion that the roasting period has been too short, with too high a temperature. The charge has evidently agglomerated before the maximum possible of lead has been worked from it, and a setting up stage might have supplemented the routine work with advantage in the yield of lead.

The composition of the pig lead from the same charge— the sample representing ten pigs — is given below. In this connection, it may be stated that the scheme of analysis followed for this and the succeeding estimations of the qualities of the Missouri leads is sub- stantially that of Fresenius * for soft leads, with the exception that the silver was commonly estimated by cupellation instead of by the .method of precipitation as chloride :

GRANBY (FLINTSHIRE) LEAD.

Arsenic 0.01640 percent.

Antimony 0.00077 per cent.

Silver 0.00029 percent.

Oopper 0.01210 per cent.

Iron .'. 0.01711 per cent.

;Zinc 0.00066 per cent.

Nickel « •. a trace

Lead, by difference 99.95267 per cent.

100.00000

(b) Treatment in the ordinary Air Furnace : Two of this form are in use at the Granby works. Each receives an average charge of 1,500 Ibs. of No. 1 ore, worked off in twelve hours, equivalent to 42,000 pounds of mineral per week as the aggregate work of these furnaces. During the week there are consumed twenty-one cords of wood. The yield of similar ore is about the same in both forms of reverberatory. The wear and tear of the common form is claimed to be somewhat greater than that of the Flintshire, and hence the campaign is shorter. On the other hand the cost of the furnace is much less than that of the new form — being usually about five hundred dollars per furnace, including sheds — so that the cost of treatment is not so much swelled by the item of interest on investment.

The following are the dimensions of the common reverberatory at Granby. The form described is usual throughout the lead regions of the State, the difference being in size and in the relative dimen- sions of the parts :

Length of hearth 9 feet.

Width of hearth at fire bridge 3 "2 inches.

* Jahresbericht fur Chemie, 1870.

46 LEAD FURNACES AND PRODUCTS.

Length of fire bridge 2 " 6 inches.

Thickness of fire bridge at top 0 " 8 inches.

Thickness of fire bridge at base 2 " 6 inches.

Width of fire box 2 » 6 inches.

Length of fire box 5 "6 inches.

Inclination of sole 9£°

Height of arch above sole at fire bridge 1 "2 inches.

Height of arch at side opposite fire bridge 1 "

The fire box is an L attachment to the furnace, and enters the hearth at a distance of thirteen inches from the front or pot end of the furnace. The flue is 8 x 12 inches in section. The charging or work- ing door is at the upper or flue end of the hearth, and the discharging and cleaning door is at the lower end. The sole is a cast-iron plate with six inches depth of slag or residue melted upon it. The corners at the pot end are rounded, for facility in reaching the charge and cleaning the furnace.

The charge, crushed to size of a pea, is thrown in through the door at the upper end and pushed down evenly over the hearth. A low fire is kept up and the charge roasted during one or one and a half hours, varying according to the amount of carbonate and the richness of the mineral. During the roasting the charge is constantly stirred, so that all parts may be worked, in turn, down the sole towards the fire bridge or hottest part of the hearth.

At the end of the roasting period, the heat is increased ; the reac- tions, already described, are setup and the lead flows down the hearth, through the discharge door into the kettle at the front end of the fur- nace. Should the materials begin to enter into fusion, they are thick- ened or stiffened by the addition of wood ashes. After the lapse of from nine to twelve hours, the lead ceases to flow ; the residue is drawn and the somewhat cooled furnace is ready for another charge.

It will be noticed that the process differs from that described for the Flintshire furnaces at the same establishment, in that the lead flows at once into the kettle, and that no second firing is given. In many respects the method is allied to that practiced at Bleiberg, but it differs from this last in the size of the furnace and in the details of the operation.

The residues are not homogeneous, so there are difficulties in arriving at even an approximation to a knowledge of their average composition. A sample yielded 3.52 per cent, of metallic lead me- chanically held in the slag, and after removing this, had the annexed composition:

Silica 21.396 percent.

Lime 4.650 per cent.

Magnesia 3.948 per cent.

LEAD FURNACES AND PRODUCTS. 47

Ferric oxide 3.680 per cent.

Alumina ~ 0.152 per cent.

Zinc oxide 7.146 per cent.

Lead sulphate 2.349 per cent.

Lead sulphide 20.929 per cent.

Lead oxide 34.914 per oent.

99.063

Total metallic lead 54.82 percent.

The polled pig lead gave, by analysis of a sample representing sixteen pigs, the following result :

Arsenic 0.01122 percent.

Antimony 0.00077 per cent.

Silver 0.00080 per cent.

Copper 0.05091 per cent.

Iron 0.01582 per cent.

Zinc 0.00090 percent.

Nickel 0.00281 percent.

Lead, by difference 99.91777 per cent.

100.0000

In the year 1875, the Granby company received weekly from the mines at Joplin about 79,000 pounds of mineral, all smelted as before stated, in the furnaces and hearths at Granby. The weekly receipts, at the same time from the mines at Oronogo, were about 60,000 pounds. The three hearths at Oronogo, which had been idle for a long time, were to be put in operation by the close of the year 1875.

The Webb diggings, three miles south from Oronogo, were yield- ing 50,000 pounds of mineral each week.

(2.) Reverleratory Treatment at Joplin, Jasper county. — At the works of Messrs. Davis & Murphy, six reverberatories of the ordi- nary pattern are run, treating weekly about one hundred and fifty thousand pounds of mineral. A charge of somewhat less than eighteen hundred pounds is therefore elaborated in each twelve hour shift in each furnace. No information could be obtained respecting the consumption of fuel. The residues together with those from other reverberatories and hearths in the district are treated in a slag fur- nace similar to that used elsewhere in the State, and which is de- scribed when treating of slag smelting.

The same firm has one other air furnace at Bently Diggings, five miles west of Joplin, and a second other, seven miles east from Jop- lin, at Scotland. The latter is run on ores from the Birch and the Grove Creek Diggings — the former, one and a half miles, and the lat- ter, one-fourth mile from the furnace site. Fifteen hundred pounds of ores, yielding one thousand pounds of metal or 66f per cent.,* are

*Schmidt, Broadheatfs Report, p. 500.

48 LKAD FURNACES AND PRODUCTS.

worked off in a nine hours shift, presumably with the ordinary amount of labor, but with what amount of fuel we are not able to state.

The following are the receipts and produce of the ore for three years :

Ore— pounds. Lead— pounds.

1872 2,060,800 1,344,000

1873 6,061,000 4,074,000

1874 6,784.000 4,536,000

giving an average yield of C6.7 per cent , on the supposition that no slag lead is included in the amount of metal produced.

At Lone Elm near Joplin, Messrs. Moffett & Sergeant, run one air furnace of common size, treating fifteen hundred pounds of high grade ore per eight hour shift. The furnace runs actively ; forty-five hundred pounds of mineral being run through in twenty-four hours with the consumption of two and a half cords of wood. Calculated to the ton of ore put in ^treatment, the fuel required is 1.1 L cord of wood, and the labor is 2.6 days of eight hour posts.

The residue resembles those generally produced, and gives, on analysis, as follows:

Silica 18.657 percent.

Lime 3.789 per cent.

Magnesia trace.

Ferric oxide .'. 2.147 per cent.

Alumina 2.350 per cent.

Antimony trace.

Zinc oxide 11.650 percent,

Lead sulphide 8.340 per cent.

Lead sulphate 2.741 per cent.

Lead oxide 50.088 percent.

99.862

The sample, which was selected with all the care practicable, gave also 3.86 per cent, of metallic lead mechanically enclosed. The lead in combination amounts to 53.35 per cent., and the total lead is, therefore, 57.21 per cent. These slags are sold for treatment in the slag furnace of Messrs. Davis and Murphy, and their market rate is about $21 per ton, against $18 per ton paid to the same establish- ment for its hearth residues.

The pig lead from the reverberatory is not kept distinct from the metal produced by the other mode of smelting, but all is refined by poling in an iron kettle. The kettle holds 12,000 pounds of lead ; the labor of two men is required in casting about 450 pigs of the polled

LEAD FURNACES AND PRODUCTS. 49

lead in twenty-four hours, and the loss in refining is said not to exceed one per cent, of the raw lead introduced. I have no analysis of this lead more recent than that published in February, 1875. The result of which is annexed :

Arsenic- 01189 per cent.

Antimony 081GS per cent.

Copper 00409 per cent.

Iron 03650 per cent.

Zinc..- 15910 percent

Silver 00994 percent

Sulphur trace.

Nickel ; .. trace.

Lead, by difference ..99.69680 per cent

100.00000

The refined lead is chiefly sold to Messrs. John T. Lewis & Bros, of Philadelphia, by whom it is used for white lead corrosion, and I am informed by the members of this well established firm that the corrosions are very satisfactory, in respect to both quantity and to the quality of the resulting white lead. It is extremely probable that the amounts of zinc and of some of the other metals in the above result are in excess of what is usual in this lead, at least more recent analy- ses are reported to show such to be the case. The Lone Elm is being largely substituted for the Tarnowitz (Silesian) lead at the Philadel- phia establishment.*^

The Lone Elm Company received in the year ending August 1, 1875, 6,500,000 pounds of mineral.

The Joplin Mining and Smelting Company operates one rever- beratory treating fifteen hundred pounds of average ores in each twelve hours shift. The residues are sold to Messrs. Davis & Murphy. The receipts of mineral for the last three years were about 15,000,000 pounds.

Messrs. Pichar c6 Brothers have three air-furnaces of the com- mon form, each treating twelve hundred pounds of high "grade ores in one eight hour shift, with an average consumption of 0.9 cord of wood, equivalent to 1.5 cords per ton of two thousand pounds of min- eral. The firm receives about fifty tons mineral per week.

(3.) The Dade County Mining" and Smelting Company, with works at Corry, Dade county, began smelting in May, 1875, running one reverberatory until December of that year, when a second and

* Arrangements have been completed for the collection of fume from the Lone Elm Furnaces. The collected material is utilized for pigments, and the resnlts are reported to be very satisfactory. G R — 4

50 LEAD FURNACES AND PRODUCTS.

similar one was completed and put in operation. Each furnace works, usually, twelve hundred pound charges in an eight hour shift, but W. M. Taggart, the president of the company, writes us that twenty-four charges have been run through one furnace in six days. According to the same gentleman, the consumption of fuel is 0.4 cord of wood per charge, or 0.66 cord per ton. The residues have been analyzed and show the composition given below :

Silica , ....23.678

Lime 12,735

Magnesia 4.321

Ferric oxide 9.134

Alumina 3.366

Zinc oxide 1.635

Lead sulphide : 15.559

Lead sulphate 2.504

Lead oxide, by difference 27.068

100.000 The sample analyzed contained no traces of arsenic, antimony or

copper, and gave no mechanically enclosed or shot lead. The lead

compounds named contain metal equal to 40.494 per cent, of the slag. From the date of inaugurating the enterprise up to January 9,

1876, the company had shipped 297,797 pounds or 3,590 pigs of lead.

A specimen of the metal forwarded us by the president, showed the

following composition :

Arsenic Trace

Antimony Trace

Silver 00177

Copper 00448

Zinc None

Nickel None

Iron 00128

Lead, by difference 99.99247

100.00000

(4) The other reverberatories treating ores from the southwest- ern region are : 3, belonging to S. B. Corn, near Joplin ; one at Baxter Springs, Kansas, belonging to Messrs. Sarver & Co. ; one at Brookline, Greene county, and one belonging to the Conoley Mining and Smelt- ing Company in Christian county.

B-KEVEKBEKATOKIES OF THE CENTRAL KEGION. (1) The Pioneer, located at Pratt's Mill, (section 26, township 43, range 14, west), Cole county, uses ores from the Dawson & Eaton, and the Bacon, Metier & Co. diggings, near Decatur, Cole county, and from the Long's diggings, Miller county.

LEAD FURNACES AND PRODUCTS. 51

The reverberatory, which was built in 1871, is of the ordinary form, with the hearth 7-J- feet by 4 feet. The fire-box is 5 feet long and 22 inches wide. The fire brick lining is of bricks from the Chel- tenham works, near St. Louis. The furnace runs usually about four months in the year.

A charge of 1,800 pounds high grade mineral is elaborated in a twelve hour turn, by the work of one smelter and one helper, and with the consumption of three-quarters of a cord of wood, or at the rate of 0.83 cord per two thousand pounds. The residues contain :

Silica (with traces baric sulphate) 24.233 per cent.

Lime 7.460 percent.

Magnesia.. 1.548 percent.

Ferric oxide 4.920 per cent.

Alumina 1.437 per cent.

Antimony oxide 0.351 per cent.

Arsenic , trace.

Zinc oxide 1.454 per cent.

Lead sulphate 2.452 per cent.

Lead sulphide 35.730 per cent.

Lead oxide, by difference.. 20.414 per cent.

100.000

Total metallic lead 51.081 per cent.

Most of the lead-oxide is in combination with the silica; this and the large amount of unchanged sulphide shown by the analysis would seem to indicate, that the time of roasting has been too hurried. As far as yield of metal is concerned, a setting up and second firing would have been advantageous.

The lead is of excellent quality. The result of its analysis is as follows :

Arsenic trace.

Antimony 0.00347

Silver 0.00105

Copper 0.00946

Iron 0.00496

Zinc 0.00517

Nickel 0.00125

Lead, by difference 99.97464

100.00000

The brand of the metal is "ONE."

(2) The Eagle Furnace (Sec. 23, T. 43, K. 14, W.,) near Pratt's Mill, Co}e county, works ore from the Eureka and Scott diggings, on the same section. The hearth is 9 feet 8 inches by 3 feet 8 inches (greatest width); the fire chamber 5 feet by 2 feet. The mineral is

52 LEAD FURNACES AND PRODUCTS.

usually mixed with some carbonate ore; 1,500 pounds are charged at a time and worked off in twelve hours, with about the same relative consumption of fuel given for the Pioneer furnace. The residues are not treated further ; they contain :

Silica 7.132 per cent.

Lime 2.939 per cent.

Magnesia 336 per cent.

Ferric oxide 1.052 per cent.

Alumina 699 per cent.

Antimony oxide trace.

Zinc oxide 945 per cent.

Lead sulphide 18.686 per cent.

Lead sulphate 1.855 per cent.

Lead oxide 65.505 per cent.

99.149 per cent.

Lead-shot in original slag1 0.10 per cent.

Metallic lead in combination 78.31 per cent.

Total lead in residue .• 78.41 per cent.

The pig lead gave the following result on analysis :

Arsenic 0.00313 per cent.

Antimony trace.

Silver 0.00029 per cent.

Copper 0 00820 per cent.

Iron 0.00461 percent.

Nickel trace.

Zinc 0.00057 per cent.

Lead, by difference 99.98320 per cent.

100.00000

(3) The Gum Spring furnace is located in S. E. i of Sec. 8, T. 42, R. 17, W., Morgan county, and is operated by the Jackson company. The ore worked is obtained exclusively from the company's diggings,, and is entirely galenite mineral. Two charges, each of 1,500 pounds, are worked off in 24 hours with the consumption of 1^ cords of wood, or 0.83 cord for a ton of mineral.

(4) Buffalo furnace, Sec. 1, T. 41, E. 19, W,, Morgan county, operated by Hon. G. Stover of Versailles, Morgan county ; runs on ore from diggings belonging to the furnace owner, situated on the same section. A charge is 1,500 pounds, two to three charges being worked off in 24 hours. The furnace was built in January, 1874. No dimensions or further particulars were obtained regarding this, or the preceding establishment.

The residues contain as under :

Silica 6.359 per cent.

Lime.... 5.625 per cent.

LEAD FURNACES AND PRODUCTS. 53

Magnesia .855 per cent.

Alumina | 1.875 percent.

Antimony oxide .075 per cent.

Arsenic oxide trace.

Zinc oxide 1.199 per cent.

Lead sulphide 11.796 per cent.

Lead sulphate 2.703 per cent.

Lead oxide, by difference 69.513 per cent.

100.000 per cent.

Total metallic lead 76.588

The brand of pig lead produced at the Buffalo is among the very best examined. It shows the composition given below :

Arsenic trace.

Antimony 0.00281 percent.

Silver 0.00114 per cent.

Copper , 0.01024 per cent.

Iron 0.00556 per cent.

Zinc , 0.00136 per cent.

Nickel 0.00115 per cent

Lead, by difference 99.97774 per cent.

100.00000 per cent.

The pigs weigh 83 pounds each, and are branded with the figure of a buffalo.

(5). The Star furnace, S. 21, T. 42, K. 18 W., Morgan county, is owned by J. P. Clark, of Versailles, and uses chiefly ore from the Coffin Spring Creek, belonging to the furnace owner. The fire box is 7 feet by 2 feet ; the hearth is 9| feet by a greatest width of 3 feet. The fire brick are made by the Oak Hill Company, and last usually about four months. Three charges of 1,500 Ibs. each, are treated every 24 hours, by the labor of two smelters and one helper. The residues yield by analysis :

Silica 14.349 per cent,

Lime 5.932 per cent.

Magnesia 1.007 per cent.

Ferric oxide 2.323 per cent.

Alumina 371 per cent.

Antimony oxide 086 per cent.

Arsenic oxide 959 per cent.

Zinc oxide 886 per cent.

Copper oxide trace.

Lead sulphide 5.334 per cent.

Lead sulphate 5.085 per cent.

Lead oxide, by difference 63.868 per cent.

100.000 per cent.

54 LEAD FURNACES AND PRODUCTS.

The lead compounds in the above contain 67.19 percent, metallic lead, in addition to 0.25 per cent, of shot lead in the original residue. The lead gave on analysis the following result :

Arsenic 0.01086 per cent.

Antimony 0.00513 per cent.

Silver 0.00029 per cent.

Copper 0,01376 per cent.

Iron 0.00462 per cent.

Zinc 0.00090 per cent.

Nickel 0.00085 per cent.

Lead, by difference.. 99.96359 per cent.

100.00000 per cent.

The lead is more arsenical than any analyzed ; probably the charges contain a notable amount of arsenical pyrites or some arsenical copper ore.

(6). Wyan Spring furnace, S. 32, T. 42, K. 17 W., Morgan county, is owned by T. M. Avery, of Chicago, but is operated under the super- intendence of Gooding, of ^Versailles. The ore is obtained from

the workings connected with the furnace, and is almost entirely galenite.

The hearth has 10 feet length and a greatest breadth of 5.25 feet. The fire box is two feet wide and six feet long. The fire bricks used in the construction are made at Oak Hill and Marine, Illinois. A charge consists of 1,800 Ibs. mineral, and is worked off in 24 hours by two smelters and one helper, and with the consumption of 1.13 cords- wood. The rate of expenditure of fuel is therefore 1.25 cords wood per two thousand pounds ore put in treatment.

The roasting period lasts commonly one hour, when the tempera- ture is raised. A second roasting and firing, and finally a pressing of the residues follow, so that, while the consumption of fuel is greater, the residues are worked cleaner, as exhibited in the annexed result of analysis, and the gain in lead is decidedly disproportionately greater than the expense entailed by the use of the additional fuel :

Analysis of Wyan Spring Residue.

Silica ..: 18.203 percent.

Lime 17.782 per cent.

Magnesia 1.755 percent.

Ferric oxide 5.229 per cent.

Alumina 294 per cent.

Antimony oxide 065 per cent.

Zinc oxide.. 996 per cent.

Lead sulphide 16.456 per cent.

Lead sulphate 2.104 per cent-

Lead oxide ~ 27.005 per cent.

99.889 per cent.

LEAD FURNACES AND PRODUCTS. 55

The residue contains no appreciable amount of mechanically enclosed lead ; the total lead contained in the lead compounds is 40.76 per cent, of the slag.

The resulting lead has the following centessimal composition:

Arsenic 0.00338

Antimony , 0.00048

Silver; 0.00057

Copper 0.01002

Iron 0.00428

Zinc 0.00139

Nickel 0.00202

Lead, by difference 99.97786

100.00000

The furnace runs about two weeks in each month, in which time is smelted the total product from the diggings of the company, as well as some purchased ore.

(7). Bond's Air furnace— S. E. qr. JST. E. qr., S. 16, T. 40, E. 17 W., works chiefly ore from the Buck Creek diggings, about three miles distant, southerly from the furnace/ It was built in 1867, by the Messrs. Bond, but is now leased by them to Messrs. Wangelin, Bradbury & Co., of Jefferson City.

The following dimensions have been furnished us :

Length of hearth 8 feet.

Greatest width 4 feet.

Narrowing down however, towards each door, to a width of ten inches.

Length of fire box 4 feat.

"Width of fire box 2 feet.

Depth of fire box 2 feet.

Height of fire bridge above grate 2 feet.

The slope of the hearth is eighteen inches in the eight feet length.

The fire brick lining is from the establishment of Messrs. Evans & Howard, St. Louis, and is reported to last during two campaigns of a furnace. The furnace runs from four to six months in the year.

The charge is fifteen hundred pounds worked off in twenty-four hours, consuming three-fourths cord of wood. The yield is 12 pigs of 90 pounds each, or 1,080 pounds of metal, equivalent to 72 per cent, from the ore put in treatment.

The roasting period covers about three-fourths of an hour, but the comparatively clean character of the residues would seem to indicate that it has been repeated. There appears to have been a

56 LEAD FURNACES AND PRODUCTS.

setting up of the residues also. A sample of the residue gave the following composition on analysis :

Silica 20.211 per cent.

Lime 7.791 per cent.

Magnesia 1.641 per cent.

Ferric oxide 4.459 per cent.

Alumina 557 per cent.

Antimony oxide 132 per cent.

Zinc oxide 417 per cent.

Lead sulphide.... 26.152 per cent.

Lead sulphate 1.932 per cent.

Lead^oxide, by difference 36.708 per cent.

100.000

A little baric sulphate is included in the per centage of silica, but no separation was deemed necessary.

The residues contain no shot lead. The total per centage of metallic lead contained in all the lead compounds is 58.017.

The brand of pig is "GRAVOIS." It gives on analysis, as fol- lows :

Antimony 0.00495

Silver 000084

Copper 0.00556

Iron 0.00411

Zinc 000181

Nickel 0.00195

Lead, by difference 99.98078

100.00000

(S) The Linn Creek furnace, Sec. 25, T. 39, R. 17 W., Camden county, is owned by Draper & McOlurg, and was built in 1871. The fire box is 4.5 by 2 feet. The dimensions of the hearth are 8 feet by 4. The interior lining is of fire brick from the establishment of Messrs. Evans & Howard of St. Louis. The campaigns of the furnace have been, for the year 1871, three months ; for 1872, four months ; for 1873, six months, and for 1874, nine months, with new lining after each campaign.

The ore treated is mainly from the Buck Creek diggings, eight and a half miles distant from the furnace. The charge is usually 1,500 Ibs. elaborated during the 24 hours with the consumption of one cord of wood. It yields twelve pigs of 84£ Ibs. weight each, or 1,014 Ibs. metal, equal to 67.6 per cent, of the ore treated. The residues hold no shot lead and contain:

Silica 26.342 per cent

Lime 5 234 per cent.

LEAD FURNACES AND PRODUCTS. 57

Magnesia 889 per cent.

Ferric oxide 4.073 per cent.

Alumina 1.187 per cent.

Antimony oxide..... * trace.

Arsenic oxide trace.

Zinc oxide... 519 per cent.

Lead sulphide 36.445 per cent.

Lead sulphate 4.529 per cent.

Lead oxide, by difference 20.872 per cent.

100.000

The lead compounds are equivalent to 54.029 per cent, of metallic lead in the residues.

The pig lead is branded "Draper & McClurg," and gives the fol- lowing result on analysis :

Arsenic 0.01423 per cent.

Antimony : 0 00639 per cent.

Silver 0.00043 per cent.

Copper 0.01511 per cent.

Iron 0.00376 per cent.

Zinc 0.00136 per cent.

Nickel , 0.00135 percent.

Lead, by difference 99.95737 per cent.

100.00000

A small furnace has been lately erected in Benton county for the treatment of ores obtained in the explorations now being actively pushed in the sub-carboniferous rocks of the vicinity. At the time of our visit the furnace was not running.

The other reverberatories in counties included in the central lead district, and of which no particulars can be given, are as follows :

Marmaduke Sec. 19; T. 49; K. 19 W.; Saline county.

Old Scott Sec. 26; T. 49 ; R. 19 W.; Cooper county.

Collin's Sec. 19; T. 49 ; E. 18 W.; Cooper county.

Handlin Sec. 9; T. 42 ; R. 17 W.; Morgan county.

Otterville Sec. 21 ; T. 45 ; R. 19 W.; Morgan county.

Eanes&Berry Sec. 32; T.44; E. 14 W.; Moniteau county.

Eureka .Sec. 23; T. 43; R. 14 W.; Cole county.

PrattsMill Sec. 26; T. 43 ; E. 14 W.; Cole county.

Pioneer Sec. 25; T. 41 ; E. 14 W.; Miller county.

Grassroot Sec. 23 ; T. 41 ; E. 14 W.; Miller county.

The total number of air furnaces in the central distrit is 19. The following analysis of the Handlin (Morgan county) furnace residue is added :

Silica 16.860 per cent.

Lime 9.723 per cent.

58 LEAD FURNACES AND PRODUCTS.

Magnesia 2.484 per cent.

Ferric oxide ]

[ 5.940 per cent.

Alumina J

Antimony oxide 0.215 per cent.

Arsenic oxide trace.

Zinc oxide 1.829 per cent.

Cupfic oxide nil.

Lead sulphide 23.322 per cent.

Lead sulphate 3.061 per cent.

Lead oxide 36.607 per cent.

100.041

The residue contains 0.28 per cent, of free or mechanically mixed lead, while the total content of metallic lead is 56.348 per cent.

The Eanes & Berry furnace, according to Schmidt's report (page 558), works usually charges of twelve hundred pounds weight. At- tempts to increase the weight to a ton, or even to fifteen hundred pounds were unsuccessful, having invariably been found to be disad- vantageous in regard to the yield from the ore. The dimensions of the furnace are not given.

(C.) THE SOUTHEASTERN REGION.

rt

(1) St. Joe. Furnaces: The estate of the St. Joe. company includes eighteen hundred acres of land, chiefly in St. Francois county. The mining operations are mainly concentrated upon the deposits in Sec. 33 ; T. 38 ; R. 4 E., about six miles from Cadet, a sta- tion on the Iron Mountain Railroad. The character of these deposits and their geological position are so closely allied to those of the well known Mine la Motte property, and both have been so fully described elsewhere, that repetition in this report would be superfluous.

The ores receive mechanical treatment and concentration before furnace treatment. Their composition is shown in the results of analyses of the galenite from the different Missouri localities (ante, pp. 16 and 17). The furnace yield is said to range between 65 and TO per cent, metal.

The smelting establishment includes eight reverberatories of the common form, but with larger hearth area than those in general use in the State. The dimensions are :

Length of hearth 14 feet.

Width of hearth.... : 3 feet.

Length of fire box 5 feet.

Width of fire box 4 feet.

So that the areas of the hearth and grate are to each other nearly as two to one. The charge is larger, being two thousand pounds

LEAD FURNACES AND PRODUCTS. 59

mineral, worked off in eight hours, or three such charges being treated in one day. The fuel consumed is three-fourths of a cord of wood per charge or per ton. There are required two days (of eight hour's) labor per ton of ore treated.

The residues are saved for treatment for nickeliferous matte and lead at such time when the proper furnaces have been decided upon and erected. Their value for nickel and cobalt as well as the full composition is shown in the following result of analysis :

Silica 26.252 per cent.

Lime 9.908 percent.

Magnesia 3.704 percent.

Ferric oxide 11.533 per cent.

Alumina 3.223 percent.

Arsenic 0 059 per cent.

Antimony trace.

Zinc oxide trace.

Copper sulphide 0.981 percent.

Cobalt sulphide 0.523 per cent.

Nickel sulphide 0.777 per cent.

Lead sulphate 3.455 per cent.

Lead sulphide 37.792 per cent.

Lea^l oxide, by difference 4.793 percent.

100.000

A special estimation of lead by humid analysis gave a total of 38.695 per cent in the residue.

The slags are richer in unchanged sulphide and poorer in oxide of lead than any thus far examined. Inferentially the heat has been too great for advantageous roasting, or the time too short fqr the weight of charge on the sole; but as these residues are intended for further treatment by a method looking to the winning of the lead and the production of a .nickel matte, their richness in metallic lead is for the present a secondary matter.

ANALYSIS OF ST. JOB EEVERBERATORY LEAD.

Arsenic 0.00183 percent.

Antimony 0.00675 per cent.

Silver '. 0.00405 percent.

Copper 0.06394 per cent.

Iron 0.00137 percent.

Zinc 0.00082 per cent.

Nickel trace.

Lead, by difference , 99.92124 per cent.

100.00000 (2) Des Loge furnace, in St. Francois county, was started in

LEAD FURNACES AND PRODUCTS.

June of the present year. The ores treated are similar to those re- duced at the St. Joe, being, in fact, extracted from the same deposit, the mines of the two companies being only about one thousand feet apart. The ore from the mine yields, by humid analysis, upwards of nineteen per cent, metallic lead, and contains the following amounts of foreign metals : Copper, 0.798; zinc, 0.611 ; nickel and cobalt (not separated) 0.137 ; iron, 2.240, chiefly as pyrites, some little, however, occurring as oxide in the limestone gangue.

An excellent system — the most complete in the State — has been adopted for the mechanical concentration of the ores, and the ca- pacity is reported to be equal to the handling of one hundred and twenty-five tons of raw ore daily. A Blake's breaker, JNo. 5, makes the preliminary crushing of the ore, whence it passes to two setts of rolls, the larger of which has a twelve inch face, the smaller being fourteen inches in diameter, with a fourteen inch face. The crushed ore is sized by four revolving screens or trommels, which yield seven grades of mineral, corresponding to 19 (and over), 12, 8, 6, 4, 2 and 1- thirty-second of an inch diameter. The largest size is returned to the rolls, the others are passed to jigs, the coarser being treated in those of the Rittinger system ; the finest being classified into four grades^ of which the two coarsest are treated in an eccentric jig and the other on a Rittinger table, A seventy-horse-power engine furnishes the motive power. Eight men are required for a post of twelve hours, representing the treatment of some sixty tons raw ore. The estab- lishment was designed by Mr. Ferdinand Stolinski and erected under his personal supervision. In the following table are given the yields of the products in metallic lead and the content of foreign metals, the numbers corresponding to the recognized grades at the works:

Lead — per cent.

No. 1 63.61

No. II 76.42

No. Ill 67.96

No. IV 76.93

No. V 74.42

No. VI 73.68

€oarse " chats" 35.238

Middlings 31.076

Fine " chats" 11.620

In No. I.-VI. (inclusive) the lead was estimated by fire assay, the mean of two results being given ; the trace of antimony was found in ten grammes of the materials. The lead in the " chats " and "mid-

Iron — per cent.

1.559

Zinc— per cent.

1.276

. Nickel and Copper — Cobalt — per cent. per cent.

0.167 0.573

Anti- mony.

trace.

0.067

0.237

0.040

0.042

trace.

0.823

0.670

0.091

0.078

trace .

0.655

0.689

0.132

0.004

trace.

0.928

0.433

0.092

0.039

trace.

1.761

0.249

0.226

0.039

trace.

6.185

1.006

2.735

0.480

trace.

9.911

2.002

2.627

r Ni O. 168 lCo.0.857

trace.

27.521

trace.

2.622

1.107

trace.

LEAD FURNACES AND PRODUCTS. 61

dlings ;' was reached by weighing as sulphate in the ordinary process of humid analysis, and the results are higher by at least five per cent, than if the usual fire assay had been made.

One furnace of the Flintshire pattern has been put in operation. Twenty-five hundred pounds of dressed mineral are charged at a time. The charge is elaborated in ten hours. Thirty pounds of fluor spar (calcium fluoride) are added to a charge, with a view probably to getting rid of some of the silica of the charge. The average slag shows a composition, as follows :

Lead sulphate 1.299 per cent,

Lead sulphide 40.105 per cent.

Lead oxide 9.313 per cent.

Nickel and cobalt oxides 0.0911 per cent.

Copper oxide 0.903 per cent.

Ferric oxide 10.874 per cent.

Calcium fluoride 0.711 per cent.

Alumina , 0.227 per cent.

Lime 12.552 per cent.

Zinc oxide 2.303 per cent.

Magnesia 3.218 per cent.

Silica 16.987 percent

99.404 A sample of the pig lead gave the following:

Lead, by difference 99.93383 percent.

Iron 0.00307 per cent.

Zinc 0.00398 per cent.

Copper 0.05872 per cent.

Silver 0.00045 per cent.

Arsenic, antimony, nickel ; traces*

100.0000

An analysis of the dross or skimmings from the lead pot was also made and is here introduced to show the concentration of certain metals in the process of refining by poling in the lead pot. The esti- mation of the lead and foreign metals (excepting silver) was made, the other constituents not being determined. In one hundred parts of the dross there are —

Lead 87.597

Iron 0.638

Zinc 0.313

Nickel 0.703

Copper, 0.987

Antimony ,trace

Silver not estimated.

The lead was estimated as sulphate. *In 100 grammes.

LEAD FURNACES AND PRODUCTS.

[The Ash Grove Mining Company, operating in T. 30, R. 24 west, have taken out upwards of forty thousand pounds of ore in explora- tions of less than four months. I have no information concerning the character of the deposit, nor of the details of the smelting, if any have been started.]

(3.) The Saline Valley Mining Company, operating the Avon mines, Sec. 12, T. 35, R. 7 E., Ste. Genevieve county, have two rever- beratories for ore treatment, and a slag furnace for residues. The ores occur similarly to those at La Motte and St. Joe.

(4.) The Frumet Company (owning 1,300 acres in Sees. 28, 33 and 34, T. 40, R. 3 E , Jefferson county), have one reverberatory of the Flintshire pattern, and a cupola for residues. A sample of the lead produced gave the following composition of analysis :

Arsenic 0.00004

Antimony 0.00007

Silver 0.00179

Copper ' 0.04399

Iron 0.00282

Zinc 0.00240

Nickel... 0.00063

Lead, by difference '. 99.94826

100.00000 II.— ILLUSTRATIONS OF HEARTH TREATMENT.

A general outline of hearth treatment has been given on pre- ceding pages. The forms of apparatus in use in the State are either the dngle tuyere, old fashioned hearth, or the more recently intro- duced American water-back hearth, commonly with three tuyeres. This latter form has been described at sufficient length for purposes of this report in the section devoted to the general practice of lead metallurgy. The details which will be given under the present head- ing, though somewhat meagre, will be found sufficiently full for reach- ing general conclusions with respect to the economics of the method. This is the more especially true since the variations in the dimensions of the hearths and the weight of charge treated on them are not wide as in the case of the reverberatory, and since as a general thing the purer and higher grade ores alone receive treatment. The results of analyses of slags or residues which are given in this section, while perhaps of value to those who may submit them to further treatment in the slag furnaces, can give no correct ideas of the thoroughness with which the lead may have been extracted, unless, indeed, the whole conditions of weights of materials introduced, of loss by volitiiiza-

LEAD FURNACES AND PRODUCTS. 63

tion, and of amount of residue produced, are given as factors in our calculations. The fact that these residues generally contain uncon- sumed fuel, and frequently, also, the lime which has been added as the so-called flux, may make the per centage of lead seem small in some instances, while, if it were possible to calculate the wastage back upon the original ore, it is really much greater. The difficulties in this respect are even more serious than those which obtain in the case of the reverberatory treatment, where, if it were possible to know the true and full composition of the ore, and the residue, and the weight of the latter produced, the chief disturbing element would be the foreign matters introduced by the wear of the furnace linings. Unfortunately, no such data as we desire exist for any of the Missouri furnaces, for no attempts are made to control or improve empirical results by stochiometrical calculations.

The order adopted for the reverberatories will be followed in con- sidering the hearth method.

A. — SOUTHWESTERN REGION: (1.) The Granby Company operates six of the improved hearths. The common duty of a hearth is about 3,000 pounds No. 1 block mineral worked off in an eight hour shift. The labor required for this amount of ore is two smelters and one helper — the Jatter serving two or more hearths by delivering ore and coal to them. Two shifts are usually worked in a day for six days, equivalent to the treatment of 216,000 pounds of mineral, yield- ing 181,200 pounds of metal, or 70 per cent. For the production of this amount of metal there are consumed 660 bushels of charcoal and 60 bushels of lime for so-called flu-x. The latter costs 25 cents per bushel.

The lead produced is somewhat purer than that produced by the reverberatories, as will be seen from the subjoined analysis, and a comparison of these results with those given while treating of the Flintshire and ordinary air furnace results at Granby. This result may be due to features inherent in the process, or it may be ascribed to greater purity of ore put in treatment:

Granby Hearth Leads.

1. II.

Arsenic 00019 0.00124 per cent.

Antimony 00198 0.01085 per cent.

Silver 00045 0.00057 per cent.

Copper 00479 0.00780 per cent.

Iron 00220 0.00367 per cent.

Zinc 00142 trace.

Nickel 00047 0.00087 per cent.

Sulphur trace. trace.

Lead, by difference 99.98850 99.96905 per cent.

100 00000 100.00000 per cent.

LEAD FURNACES AND PRODUCTS.

No 1. is an analysis already published (in Report of Board of Curators of State University for the years 1874-75) ; No. 2. is a recent analysis of a sample representing 23 pigs.

The Granby Mining and Smelting Company have also three hearths at Oronogo, Jasper county, which have not, however, been operated for some time, the ores mined at that place having been sent to Granby for treatment.

(2.) At Lone Elm, Jasper county, Messrs. Moffett & Sergeant have three hearths of the newer form. Each treats three thousand pounds of high grade ore per shift, with three shifts per day. Fifteen bushels of charcoal are required for the treatment of the three thou- sand pounds of mineral. The yield is 66.6 per cent, metal, with the following composition;

Arsenic 00027 per cent."

Iron 00777 per cent.

Zinc 02071 percent.

Copper 00463 per cent*

Nickel 00031 percent.

Antimony 0026(3 per cent.

Silver 00025 per cent.

Lead, by difference 99.96340

100.00000

(3.) With three hearths, the Joplin Mining and Smelting Com- pany treat 108,000 pounds of mineral per week, which, at two eight hour shifts per day, would correspond to 3,000 pounds per shift. The yield is reported at 66.6 per cent, of lead. No details respecting these, nor the following hearths in the southwestern region have been obtained.

Biggins & Chapman 3 Hearths.

Thurmau Mining and Smelting Co 1 "

S. B. Corn & Co 2 "

Neosho Manufacturing Co 1 "

These with those above described, give a total of twenty-two hearths for the district.

(b) CENTRAL REGION— The central lead region furnishes but one illustration of the hearth treatment. It is situated in Sec. 17, T. 41, R. 17, W., in Morgan county; was built in 1869, and belonged to the Messrs. O'Brien. It belongs to the old form, single tuyere hearth, which is of less capacity than the improved form, treating 6,000 pounds of mineral in three eight hours shifts. The yield is usually sixty pigs of sixty-seven pounds each, or 4,020 metal, equivalent to 67 per cent.

LEAD FORNACES AND PRODUCTS. 65

of the ore put in treatment. The blast is furnished by bellows moved by water-power.

A sample of the residue gave, on analysis, the following result :

Silica, with unconsumed charcoal and a little baric sulphate 43.065 per cent.

Lime •••• 5.226 per cent.

Magnesia 1.345 per cent.

Ferric oxide 3.021 per cent.

Alumina trace.

Antimony oxide 0.334 per cent.

Zinc oxide 0.456 per cent.

Lead sulphide 28.943 per cent.

Lead sulphate 0.432 per cent.

Lead oxide 19.219 per cent.

99.935

The lead compounds in the above contain 42.492 per cent, of metallic lead. The original slag showed but 0.07 per cent of shot or mechanically enclosed lead, separated in the operation of preparing the sample for analysis.

C — Southeastern Region — (1) The Hope well furnace, Washing- ton county, has been in operation since 1839.* The character of the ore treated is shown in the test of results of analysis [Nos. XXXIV and XXXV, page 17], The hearth used is the old form, twenty inches wide by twelve deep, with a single tuyere, the blast being supplied by a double acting bellows operated by an overshot water- wheel. Of the amount of ore treated and of the consumption of fuel we were unable to learn any particulars. The usual time is a shift of eight hours or the period required to produce twenty-four pigs of sixty-one pounds each, or 1,464 pounds of metal. As this furnace is of the same character and size as the O'Brien hearth, just described, it may be presumed that the ore worked to produce this weight of metal was about two thousand pounds, giving a yield of 73.2 per cent, for the ore put in treatment. In the year 1875, this furnace received 410,000 pounds of ore, and produced 5,130 pigs or 312,930 pounds of metal, corresponding to a yield of 76.3 per cent. The metallic produc- tion probably included some slag lead, for the Hopewell residue are treated in a slag furnace; so that there is probably very little risk in assuming the yield to be about 73 per cent, as before calculated.

The residue has the following composition :

Silica 36.348 per cent.

Lime 3 604 per cent.

* Dr. Litton (in Swallow's Keport) pp. 58 and 59. G R— 5

66 LEAD FURNACES AND PRODUCTS.

Magnesia 1.436 percent.

Ferric oxide 2.707 per cent.

Alumina 0.052 per cent.

Antimony oxide 0.168 per cent.

Arsenic oxide 0.218 per cent.

Zinc oxide 2.527 per cent.

Copper oxide a trace

Lead sulphide 19.647 per cent.

Lead sulphate 2.913 per cent.

Lead oxide, by difference 30.383 per cent

The total per centage of metallic lead in the residue is 47.267

100.000

(2) Perry Furnace^ one and a half miles from Potosi, Washing- ton county, is a hearth of the old pattern and of the size as that given for theHopewell. The blast enters through one tuyere of two and a half inches diameter and is supplied by a Sturtevant blower, No. 3. The ore is prepared by crushing by hand on iron grates.

The length of time required for the production of thirty pigs of seventy pounds each, (2,100 pounds of metal) constitutes a shift, in which are worked two smelters and a helper as usual. There are commonly treated in this time about three thousand pounds of mineral with the consumption of ten bushels of charcoal. This fur- nace is very actively worked, its production in 1875 being 14,600 pigs,

or 1,022,000 pounds of metal, corresponding to 487 shifts of thirty pigs each.

The residues are treated in the same hearth after concentration by washing. The second residue, or those resulting from the re-smelt- ing, are sold for treatment in the slag furnaces of the vicinity. The hearth residues from the original ore have the following composition :

Silica 25.335 per cent.

Lime 4.230 per cent.

Magnesia 0.711 per cent.

Ferric oxide 1.414 per cent.

Alumina 1 912 per cent*

Nickel oxide 0 746 per cent.

Zinc 0.591 per cent.

Arsenic oxide 0.023 per cent

Lead 48.577 percent.

Sulphur, sulphuric acid and oxygen in combination with lead not estimated.

The Perry pig lead gives, on analysis, the following :

Arsenic 0.09674 percent.

Antimony 0.00502 per cent.

Silver 0.00190 per cent.

Copper 0.00490 per cent.

Iroll 0.00436 percent.

Zinc 0.00598 per cent.

Lead, by difference 99.97191 per cent.

100.00000

LEAD FURNACES AND PRODUCTS. 67

(3) Voile Furnaces — The estate of the Yalle Company com- prise 4,500 acres, chiefly in the counties of Jefferson and St. Francois. The deposits on Sec. 7 and 8, T. 38, K. 5, E., were discovered as early as 1824, by Joseph Schuts, and have been worked with but little inter- ruption since that date.

The furnace includes two hearths and a cupola for slag treatment. The hearths have each a single tuyere ; the blast being furnished by a No. 6 Sturtevant blower, run by a 30 horse power engine. The hearths are 18 inches by 14 inches in section. In an eight hour shift there are treated 3,500 pounds ot ore, producing thirty-three pigs of seventy-five pounds each, or 2,475 pounds of metal of the "Kozier" brand. This yield corresponds to 70.7 per cent. For the Valle brand of metal, there is used a previously calcined and sorted ore which is charged, to the same amount, in the Scotch hearth, producing thirty pigs of eighty pounds each.

During each shift a hearth requires four bushels of charcoal and one-twentieth cord of wood. The charcoal is supplied to the com- pany by the burners at a cost of eight cents per bushel, the company cutting the wood. Occasionally, when the mineral is not very clean, a little lime is used.

The ore is worth $29 per miner7s thousand when lead is worth seven cents per pound, and $1.50 additional per thousand for each one-quarter cent advance in the market price of the metal.

The hearth residues are treated in a small slag cupola. They show the following composition :

Silica 8.971 per cent.

Lime 3.308 per cent.

Magnesia 0.100 per cent.

Ferric oxide 4.366 per cent.

Alumina 0.061 per cent.

Arsenic and antimony traces.

Zinc oxide 18.129 per cent.

Copper oxide 0.243 per cent.

Lead sulphide 22.922 per cent.

Lead sulphate 1.945 per cent.

Lead oxide 39.390 per cent.

99.322

Metallic lead in above 57.744

The two brands of pig lead procured at the the Valle furnaces are composed as under :

Eozier. Valle.

Arsenic 0.00925 trace.

Antimony .- 0.00184 0 00214

68 LEAD FURNACES AND PRODUCTS.

Silver

Rozier. 0 00(315

Valle. 0 00326

0 03742

0 041fi'"j

Iron

002497

0 00453

Zinc

0 00118

0 00^94

9991919

99 94548

100.00000 100.00000

During the year 1875, there were smelted 602,320 pounds of ore, producing 1,801 pigs, or 135,075 pounds of Rogers' brand, and 3,589 pigs, or 287,120 pounds of Vall6 brand ot metal, giving a total of 422,195 pounds of lead, equivalent to 70.09 per cent, of the ore treated. The residue gave, by further treatment in the slag furnace, 929 pigs of 60 pounds each, or 55,740 pounds of Phcenixlead. [See section on slag smelting, page 75.]

(4.) Mine La Motte. — Historically, as well as economically, Mine La Motte is one of the most important and interesting of the lead developments in the State. Its estate includes twenty-four thousand acres in Madison county, on some parts of which lead ores appear to have been discovered, as early as the year 1723, by Renault and La Motte, the last named beginning work in the following year. The discovery of nickel and cobalt minerals in association with the lead ores in the deposits at this locality, and the very considerable importance which the production of nickel matte as an incidental product has reached, has of late greatly increased the interest which is attached to the well known and frequently described Mine La Motte.

The metallurgical operations on this property comprehend the treatment of the ores by the hearth process and the further treatment of the residues and roasted ores, notably nickeliferous, in the cupola furnace for the production of a slag lead and a nickel matte. The latter is further treated by concentration for market.

The hearths are two in number, of the newer form. They are two feet wide by twenty-two inches deep, with three tuyeres each ; the blast having usually a pressure of four ounces. Each hearth works thirty-two hundred pounds of material in about six hours time, with two smelters and one helper serving the two hearths. Eight bushels of charcoal are consumed for this work. The product is twenty-five pigs of eighty pounds each, or 2,000 pounds of metal, equivalent to 68.7 per cent.

From March 27, 1875, to December 25, of the same year, 7,906 cars of ore were crushed, producing 6,786,279 pounds of clean mineral for furnace treatment. In the same time there were smelted 5,808,747

LEAD FURNACES AND PRODUCTS. 69

pounds of this washed ore, producing 49,104 pigs, or 3,928,320 pounds of lead, of which 41,136 pigs, or 3,290,880 pounds were from the hearths, and 7,968 pigs, or 637,440 pounds were produced by the cupola. With an average yield of 68.7 per cent., the amount of ore treated to produce the above named amount of metal from the hearths would have been 4,790,048 pounds, leaving for the cupolas 1,018,520 pounds.

The amount of residue produced by the hearths at Mine LaMotte is reported at from 10 to 17 per cent, of the ore put in treatment, or, say an average of 13.5 per cent. A charge of 3,200 pounds would therefore yield 431 pounds of residue, the composition of which we find to be as under:

Silica 15.536 per cent.

Lime 10.237 per cent.

Magnesia 5.488 per cent.

Ferric oxide 15.656 per cent.

Alumina 1.883 per cent.

Nickel sulphide 1.021 per cent.

Cobalt sulphide 719 per cent.

Cuprous sulphide 154 per cent.

Antimony and Arsenic trace.

Zinc oxide 1.315 percent.

Lead sulphide 20.999 per cent.

Lead sulphate 3.904 per cent.

Lead oxide, by difference 23.087 per cent.

100,000 With a yield of 43.011 per cent, of metallic lead.

The nickel and cobalt compounds in the above result, corres- pond, respectively, to 0.666 per cent, nickel and 0.466 per cent, cobalt. An analysis of a second sample gave W. C. Minger, in this laboratory, 1.242 per cent, nickel sulphide (=0.852 metallic nickel) and 0.675 per cent, cobalt sulphide (= 0.438 cobalt). The mean, which proba- bly represents a fair run of the residues, is 0.759 per cent, metallic nickel and 0.452 per cent, cobalt. These residues are treated further for metallic lead and a concentrated nickeliferous mass or nickel matte, by a method which will be found detailed in the section devoted to the methods of slag or residue treatment. The matte is a source of no inconsiderable revenue to the company.

The hearth lead produced at Mine La Motte we find to have the following composition :

Arsenic 0.00034 per cent.

Antimony 0.00119 per cent.

Silyer 0.00345 per cent.

70 LEAD FURNACES AND PRODUCTS.

Copper 0.01999 per cent.

Iron 0.00248 per cent.

Zinc , 0.00164 per cent.

Nickel 0.00095 per cent.

Lead, by difference 99.96996 per cent.

100.00000

The hearths at Mine la Motte have connected with them cham- bers for fume condensation, in which are collected thirty-three thou- sand three hundred pounds of fume in three months' time, or 100.000 pounds resulting from the hearth treatment of 4,790,048 pounds of ore. The fume yields 70 per cent, metal, and is treated with residue and ore in the cupolas. The loss by volatilization in the hearths is, there- fore, 2.17 per cent, of the ore, or 3.04 per cent, of the lead produced in the treatment in the ore hearth.

SLAG TREATMENT IN MISSOURI.

Slag treatment, or the extraction of lead from the residues of the reverberatory and the hearth processes, is practiced at Granby, at Davis' & Murphy's establishment, Joplin, at Hopewell, at Perry, and at the Valle furnaces. To this list may be added the more elaborate cupola process, in use at Mine la Motte, where the residues are treated mainly for the production of nickel matte, by which a metallic lead is also recovered. The character of the material to be treated has already been indicated by the various analyses given on preceding pages, in the description of the several furnaces and ore hearths. It will be seen that the residues consist of varying admixtures of more or less scorified gangue substances with lead sulphide, sulphate and oxide — the latter both free and in combination with silicic acid — and contain besides mechanically enclosed or "shot" lead. The foreign metals of the ore, which are but slightly volatile at the temperature of treatment, are also concentrated in these residues, which, therefore, produce necessarily a more impure metal than do the original ores.

The form of furnace in use is the North of England slag hearth, so modified as to increase rapidity of handling and production, but retaining at the same time the valuable features of economy of ori-

LEAD FURNACES AND PRODUCTS. 71

.ginal plant and convenience of operation. It belongs to the class of furnaces distinguished as Krummofen, being a low shaft, usually of four feet height, with rectangular section, provided with a cast-iron bed-plate or sole sloping downwards towards the front, usually at the rate of one and a half inches to the foot, and extending outwards so as to overlap the iron pot in which the lead is received. This bed- plate carries the fire-brick lining of the sides of the furnace. A single tuyere, commonly three inches in diameter, enters the back of the furnace at a height of eight or ten inches above the sole. The "eye" or port of the furnace is about nine inches in height by one foot in width, and is closed during the operation of the furnace by well rammed, stiff clay ; through the bottom of this, at the bed-plate, a wooden tap-plug passes, which is withdrawn at about an hour after the furnace is in full blast. The exterior lead pot is divided unequally by a partition descending nearly to the bottom ; the larger division is kept filled with pieces of charcoal, over which the slag runs, and through which the lead filters and passes beneath the partition into the smaller division or moulding side of the pot. The slag passes thence into the water tank. The very considerable volatilization of the lead requires that the furnace should be surmounted by proper contrivances for ventilation.

The furnace is operated by tamping over the bed-plate abrasque composed of equal volumes of clay and coke, so arranged as to be about one inch in thickness at the port and four inches at the back. A fire is kindled with dry wood in small stacks arranged against each other in an inverted V shape, from front to back, and slightly above the tuyere in height, so as to form an unobstructed passage for the blast from back to front of the furnace. On this live coals are thrown above the tuyere, the furnace filled with charcoal, and the blast turned on to the extent of about half the usual amount. As soon as the char- coal is thoroughly ignited, the normal fuel or coke is spread over it to the depth of six inches, the full blast turned on and the slag spread evenly over the coke. At intervals the normal change of coke and slag (about one measure of the first to four of the latter) are thrown in, in such a manner that the slag is chiefly at the back and the coke mainly at the front of the furnace, and the furnace is kept full. The proper manipulation of the furnace for forming the nose is a matter of experience. The discharge of slag indicates the working, A sluggish dull-red flow of slag over the charcoal in the pot indicates too low heat, and loss of lead by mechanical enclosure ; fuming of the slag shows matte production, while a thin stream of slag, of a bright straw- yellow color, shows a proper condition of working.

72 LEAD FURNACES AND PRODUCTS.

The highly basic character of the materials smelted in these fur- naces, causes rapid wear of the linings, and a campaign is necessarily a very short one, rarely exceeding thirty-six hours. The furnace is- blown out by ceasing to charge with residues, but continuing the introduction of the fuel till no more slag runs from the tap-hole. The repairs are readily and cheaply made. No flux is added to the charge* but when practicable the residues rich in lime are mixed with furnace bottoms for treatment.

The usual duty of the slag hearth in this State is from twelve to- fifteen tons of residues, run through in the double shift of sixteen hours, requiring six workmen, as follows : One slag smelter, working the double shift, two helpers and two pot-men ; one of each in each eight hour shift.

There will be used in such a run about four thousand pounds of coke, about twenty bushels of charcoal, besides the fuel for the blow* ing apparatus. The cost of treatment will be about as under:

Labor, per ton residues 0.4 day.

Coke, " " 266 Ibs.

Charcoal, " '; 80 Ibs.

The furnace yield is about 23 per cent. lead. The other products are black-slag, lead-dross, wall accretions from the furnace and fume.. The lead is hard lead, as noted above ; it is usually refined by melting and poling in the reverberatory, but is not then as satisfactory for chemical purposes, and usually ranges in the market a half cent per pound less than the soft leads directly from the ores.

The Granby slag furnace has a horizontal section of 2 feet 6 inches by 3 feet. The slag gives the annexed composition on analysis :

Silica 37.648 per cent.

Lime 4.005 »

Magnesia 1.754 u

Alumina « 3.268 "

Ferrous oxide 2.258 "

Lead oxide 33.778 "

Zinc oxide.- 14 221

Lead sulphate 0359 "

Ferrous sulphide 1.927 "

99.2^18

Besides traces of antimony. Kegarding the ferrous sulphide as a small amount of matte, mechanically mixed with the slag, and taking the lead sulphate as a foreign matter, there remains 96.932 per cent, of true slag, with the following per centage composition and amounts of" oxygen in the respective constituents :

LEAD FURNACES AND PRODUCTS.

73

Per cent.

Ratio of O. of

Oxygen. Silica to O of bases.

Silica 38.84 per cent.

Lime 4.13

Magnesia 1.81 "

Alumina 3.37

Ferrous oxide 2.33 "

Lead oxide 34.85 "

Zinc oxide.... 1467 u

20.71 1.18] 0.72 ! 1.57 0.52 2.50 2.90J

20.71

10,17

The ratio is therefore 2 to 1, giving the formula of a bi-silicate slag with lead oxide as the chief base. It is doubtful whether the substitute of some other base for the lead oxide, by the use of flux, would be advantageous on the score of economy, even though saving of the furnace lining might also be obtained thereby.

After refining in the Flintshire furnace, the Granby slag lead has the following composition :

Arsenic 0.00101 per cent.

Antimony- 0.04975 per cent.

Silver 0.00029 per cent.

Copper 0.02965 per cent.

Iron 0.00718 percent.

Zinc 0.00180 per cent.

Cadmium 0.00276 per cent.

Lead, by difference 99.90756 per cent.

100.00000

The sample represented thirty pigs. The loss of weight in the refining operation is said to be about four per cent.

The slag-furnace of Davis & Murphy, at Joplin, (similar in con- struction and mode of operation to that at Granby), yields a black slag, with the composition given below :

Silica 24.527 per cent.

Lime 6.130 per cent

Magnesia 1.055 per cent.

Alumina 361 per cent.

Antimony oxide , trace.

Zinc oxide 10.335 per cent.

Lead oxide 47.619 per cent.

Lead sulphate 2.765 per cent.

Lead sulphide 1.165 per cent.

Ferrous sulphide 5.189 per cent.

99.146

Silica

constituents. <

27 252 —

Oxygen 14 53

Lime . .

6 811 —

1.941

1.172 —

0.47

Alumina ....

0 401 —

019

Zinc oxide

11 483 —

223

Lead oxide..,.

52.910 —

3.89,

74 LEAD FURNACES AND PRODUCTS

Deducting the last three constituents as not belonging properly to the slag, the true slag will be found by calculation to have the fol- lowing composition and oxygen ratios :

Per cent. Per cent. Oxygen of silica

to oxygen of bases. 14.53

8.72

or about 8 to 5, and showing, therefore, a mixture of singulo- and bi-silicate, with nearly 53 per cent, of lead oxide [—50 per cent, metallic lead]. This composition would seem to indicate that the slag was formed with greater corrosion of the furnace lining, but with less consumption of fuel than the Granby slag ; but, on the other hand, it would be more apt to entangle metallic lead, being somewhat thick-flowing, congealing more rapidly and of high specific gravity. The original slag contains also more matte, and is less clean than the iirst described.

The slag-furnace at Hopewell is three feet in height, with a hori- zontal section of 2 by 2^ feet. Wood is used for fuel, and the hearth residues are fluxed with some black slag from preceding operations in the slag- furnace. The black slag shows :

Per cent.

oxygen.

Silica 24.539 per cent. = 1309 = 13.09

Lime 9.896 per cent. = 2.83

Magnesia 2.773 per cent. = 1.11

Alumina 385 per cent. = 0.18

o or

Ferrous oxide 2.039 per cent. = 0.45 j

Zinc oxide 1.619 per cent. = 0.32

Lead oxide 47.920 per cent. = 3.36j

Ferrous sulphide 9.399 percent.

99570

Besides traces of copper oxide. It contains 43.56 per cent, metallic lead, and is, therefore, somewhat cleaner th?n the preceding; but, like the latter, contains nearly ten per cent, of matte. The oxygen ratio is about 9 to 6, so that the slag is even more basic than that from Joplin.

At the Valle works, 5,000 pounds residues are run through the slag-furnace in a twelve-hour shift, with the production of 18 pigs (of

LEAD FURNACES AND PRODUCTS. 75

60 pounds each) of slag lead of the brand "Phoenix." The furnace yield is, therefore, a little more than 20 per cent. The furnace is run with charcoal, and slag from the same furnace is used for flux. The

slag gives, on analysis :

Per cent. Oxygen of silica

oxygen. to oxygen of bases.

Silica 20.422 = 10.89 10.89

Lime 6.234 = 1.78]

Magnesia 0.872 = 0.35

Ferrous oxide 15.628 = 3.47

Alumina 5.233 = 2.44 "

Zinc oxide 28.432 = 5.61

Lead oxide 19.081 = 1.37

Lead sulphate 3.779

Cuprous sulphide 0.319

with traces of arsenic and antimony. The oxygen ratio of 1 to 1.5 nearly, indicates a highly basic slag, or sub-silicate with less lead than any slag described, and with a proportional increase in ferrous and zinc oxides. Such a slag should run in a thin stream, and congeal ver}- rapidly, and is very likely from its high specific gravity, to enclose metal. Besides it must be very destructive to the furnace lining, necessitating much more frequent repairs than those previously described. It is stated above that the run of the furnace producing this slag is but twelve hours, and only four thousand pounds residues. The slag lead of the Valle furnace gives on analysis, the follow- ing composition :

Arsenic 0.01556 per cent

Antimony 0.13365 per cent.

Silver 0.00525 percent.

Copper 0.09323 percent.

Iron 0.00470 per cent.

Zinc 0.00235 percent.

Lead, by difference 99.74536 per cent.

100.00000

In all furnaces of the cupola form, the ashes of the fuel become constituents of the slag. Coke ashes contain from 55 to 65 per cent, of silica, ana have alumina and ferric oxides as their chief bases, be- sides containing lime, magnesia, manganic oxide, and the alkalis. The oxygen ratio of the acid and bases is very nearly that of a bi- silicate, while the great variety of bases makes it a slag of somewhat ready fusibility. The ashes of charcoal on the other hand, contain but small amounts of silica, but are rich in bases such as the alkalis and lime. The alkalis have not been determined in any of the fore-

76 LEAD FURNACES AND PRODUCTS.

going analysis of slags ; they were but small in amount, and would be of no significance from a technical standpoint.

SPECIAL CUPOLA METHOD AT MINE LA MOTTE,

The fact that the hearth residues at Mine la Motte are notably nickeliferous, induces a modification of the slag methods above described, which has for its object the extraction of the lead and the simultaneous production of a matte, in which the nickel shall be con- centrated in amount. Besides, some of the ore deposits which are worked at that property, yield ores sufficiently rich in nickel to be passed at once to this treatment, either in admixture with the hearth residues or separately.

The process practiced belongs to the class of true cupola methods, and is the only instance offered in the State. Two forms of furnaces have been used, one with a circular and the other with a trapezoidal section, the latter being the form in use at present.

The circular cupola is 3 feet diameter, tuyeres, 8 inches above hearth plate; height from tuyeres to throat, 12 feet. The so-called square cupola is 28 inches wide in front, 42 inches at the back and 36 inches deep. Three tuyeres, diameter 2f inches, enter the back at a height of 11 inches above the hearth plate. From the tuyeres to the throat, the height is 11 feet. The usual pressure of the blast used is 10 ounces. The sole of the furnace is a mixture of one volume of coke with two of clay.

The shifts run are twelve hours duration, with five men to a shift. Fuel is coke, either from Pittsburgh or from Missouri coal, and is used in the proportion of one Pittsburgh coke to six of ore or residue, or one of Missouri coke to five of ore or residue. The ore or residue charges are about 150 Ibs. each, and seven or eight are usually charged per hour. The flux is a hematite from the Iron Mountain region, with a composition as under :

Ferric oxide 94.545 per cent.

Alumina 3.922 per cent.

Magnesia 0.401 percent.

Lime 0.129 per cent.

Silica 1.182 percent.

100.179 per cent.

There seems to be no regular or definite amount of flux used, it being proportioned to the demands of the working of the furnace, as pointed out by the experience of the workmen.

A twelve hour poste represents the treatment of 12,600 Ibs. ore, and consumption of 1,800 pounds of Pittsburgh coke. A ton of ore

LEAD FURNACES AND PRODUCTS. , 77

requires therefore, 206 pounds fuel, and at the rate of 0.8 days ]abor.

It may be mentioned in this connection, that the treatment for the production of matte is largely experimental at present, especially in the direction of the form of furnace best adapted to the work. At the present writing other forms are being erected.

The production of a twelve hour shift is 63 pigs, or 5,080 pounds metal, (giving for the furnace yield of the residue 40.32 per cent), and 1,750 pounds of first matte, besides slag.

The slag lead shows the following composition on analysis :

Arsenic 0.00125 per cent.

Antimony 0.00119 per cent.

Silver 0.00564 per cent.

Copper 0.08544 per cent.

Iron 0.00334 per cent.

Zinc 0.00458 per cent.

Nickel 0.00519 per cent.

Lead, by difference 99.89337 per cent.

100.00000 per cent. The first matte is composed as under :

Silica 19.755 per cent.

Alumina 8.549 per cent.

Lime 11.931 per cent.

Magnesia 2.701 per cent.

Ferrous oxide 9.328 per cent.

di-Perrous sulphide 26.133 "]

Ferrous sulphide 13.861

Nickel sulphide 3.387

Cobalt sulphide 1.842

Lead sulphide 1.404

Copper sulphide 726

Zinc sulphide 423 J

Matte proper.

100.095

The matte contains 2.196 per cent, nickel, and 1.194 per cent, cobalt. Minger's determinations gave 2.486 nickel and 1.195 cobalt.

William C. Minger, in this laboratory, determines the slag to have the following rational composition, (including some mechanically mixed matte) :

Silica 53.435 per cent.

Alumina, 6 219 per cent.

Lime 15. 046 per cent.

Magnesia 8.633 per cent.

Potassa 0.708 per cent.

Ferrous oxide 0.988 per cent.

Cobalt and nickel sulphides 0 793 per cent.

Zinc sulphide..... 0.436 per cent.

Diferrous sulphide 13.576 per cent.

99.834 per cent.

78 , LEAD FURNACES AND PRODUCTS.

After deducting the mechanically enclosed sulphides, it will be found on calculation, that the oxygen of the acid and bases stand to each other as 10 (nearly) to 4.5, and the slag is nearly a true bi-silicate. The small amount of ferrous oxide is unaccountable, unless the run prodacing this slag has been made with slag from the same furnace as flux, and with but little hematite. The absence of lead oxide among the bases is also noticeable.

The slag is thrown aside, excepting on occasions when its presence is deemed necessary in the charge.

The first matte is roasted in heaps, containing from fifty to seventy- five thousand pounds. The time required for roasting is from four to six weeks, and the fuel consumed is 5 cords of wood and 300 bushels of charcoal. The roasted matte has the annexed composition :

Nickel sulphate 0.186

Lime sulphate 5.442

Ferrous sulphate 1.338

Silica 7.804

Alumina , 2.221

Nickel sulphide 5.631

Cobalt sulphide 3390

Cuprous sulphide 1.908

Diferrous sulphide 31.041

Tetra-ferrous sulphide 1.154

Ferric oxide..., .. 39.877

10®.000

The roasted product is passed to a second smelting in a cupola furnace, giving a concentrated matte and slag. The second or con- centrated matte has been analyzed with the following result :

Nickel sulphide 8.310 per cent.

Cobalt sulphide 3.424 per cent.

Cuprous sulphide 371 per cent.

Zinc sulphide .*. ,930 per cent.

Tetra-ferrous sulphide 20.361 per cent.

Diferrous sulphide 57.969 per cent.

Silica 884 percent^

Lime 4.653 per cent.

Alumina 2.659 per cent.

Magnesia 776 per cent.

100.337 per cent.

It contains 5.338 per cent, nickel, and 2.220 per cent, cobalt. With this matte there is a further treatment, consisting in two roastings and a cupola smelting, which yields, finally, a concentrated matte, which is claimed to yield from 10 to 18 per cent, nickel and cobalt*

LEAD FURNACES AND PRODUCTS.

and which is passed to market. The flux used is a silicious limestone and some hematite.

The further separation of the nickel compounds and the produc- tion of commercial nickel is carried on at Oamden, New Jersey, and at some European localities, among which may be named Birming- ham, England. The processes are complicated and usually kept secret. They have no special interest in this connection, since they form no part of the industry of Missouri.

The following will exhibit the work of the furnace at Mine la Motte for six weeks (ending as below) in the year 1875 :

Date. Mineral delivered Pigs produced Matte

to furnaces — Ibs. (80 Ibs. each.) produced— Ibs.

November 20 .................. 216,071 1,750 18,000

November 27 ............ ...... 198,214 1,497 10,000

December 4 .................. 180,356 1,265 18,000

December 11 ................. 162,500 1,302 3,000

December 18 .................. 225,893 1,824 16,000

December 25 ................. 191,963 1,571 15,000

Each one thousand of mineral is really 1120 pounds, or a " miner's thousand." The matte is all first run — not concentrated.

In the same period, the following number of cars of vein-matter were crushed, producing the accompanying weights of clean or dressed mineral :

Date. No. cars Clean mineral

crushed. produced — Ibs.

November 20 ...................................................... 229 77,492

November 27 ...................................................... 187 220,908

December 4 .................. .................................... 217 158,806

December 11 ...................................................... 212 75,228

December 18 ..................................................... 207 237,186

December 25 ..................................................... 162 232,360

The cars for transporting the ore from the mines to the dressing works, carry from two to five tons, and are moved by gravity.

The capacity of the reduction works is not adequate to the hand- ling of the ore produced by the mines, the latter accumulating rapidly. The metallurgical processes and apparatus are hardly settled upon* the work being, as before stated, largely experimental.

CHAPTER III.

ECONOMICAL CONSIDERATIONS OF THE LEAD EXTRAC- TION METHODS.

The difficulty of reaching correct conclusions respecting the eco- nomics of metallurgical operations, where work is conducted empiri- cally more than in accordance with technical principles, is almost unsurmountable. At the best, only approximations can be made; and for these, even, many of the data are necessarily derived from sources which are not and cannot be positive, since they are often merely loose estimates based on judgment or prejudice, and uncon- trolled by strict business system. Where the disposition to impart information exists, (and the writer would here state that in nearly all cases, in this State, he has found a most commendable willingness to furnish information concerning the operation of lead furnaces, which he fully appreciates, and for which he returns his sincere thanks,) there is not always the ability to furnish it in the detail which is necessary to reach even close approximations.

It is a matter of serious question whether the economical condi- tions of lead smelting in Missouri have ever been examined to the extent which the importance of the subject warrants. Abundant distribution of ores of great purity and of high grade, simplifies in this State, what is otherwise a complex metallurgical problem; cheap and abundant fuel and labor — the latter, not infrequently, far from being skilled, but still regarded as adequate to the mechanical opera- tions of a reverberatory or a hearth furnace — leave abundant margin for profit, engendering the belief that the best possible is being done with the business, and preventing a consideration of those sources of possible wastage, which, if examined, might lead to improvement and thence to increased financial remuneration.

In attempting the following analysis of the surroundings of lead smelting in Missouri, and the comparison of these with those obtained elsewhere, we are met at the outset with the difficulty that no one establishment has furnished full particulars. Hence we have been forced to consider no one furnace, but to average, as it were, the details and results of all those of which we have been able to gather

LEAD FUKNACES AND PRODUCTS.

81

any particulars, and which we have detailed in our illustration given in the preceding section. The conclusions reached are, therefore, not those for any special establishment, but they may be of some value in relation to the general aspects of lead business, though even for this they cannot be positive. It will, therefore, be understood that they are not put forward as absolutely correct, but only as such close approximations as could be made from the data procurable.

It is proposed to examine into value of the reverberatory method as practiced—disregarding the few examples of the Flintshire now in use — in comparison with those of other localities ; to compare in the same manner the results of the hearth smeltings among themsel7es, and finally to inquire which of the two methods does give or can be made to give the best results with the present economical surround- ings in Missouri.

EEVERBERATORY METHODS. — The illustrations of the reverberatory method which have been given are collected in the following table, in which are given the size; the weight of the charge in pouuds; time in hours required for the elaboration of the charge and the fuel consumed for the same. From the latter have been calculated the fuel and labor required to a ton (of 2,000 pounds) of ore, together with the mean results of the twelve instances given :

Recapitulation of Results with Reverberatory Method in Missouri Furnaces.

NAMES.

Area Hearth square feet..

3 o

ft

Q

I'

H

1

tf o e

i* |l

r

0)

c 2L

OJ 0

1

: o

£13

cr

1. Lone Elm

1,500

8

0.8

1.20

2,62

2. Dade county

1 200

8

04?

066

3.32

3. Pioneer ...

34

9 15

1 800

12

075

084

1.66

4. Eagle

35 3

10

1 500

1?

063

0.84

2.00

5. Gum Spring

1,500

94

125

1.66

4.00

6. Buffalo

1 500

12

2.00

7. Star.

28 5

14

1 500

8

1.31

8. AVyan Sprin0"

52 5

12

1,800

24

1.13

1.26

3.33

9. Bonds

32

18

1,500

94

075

1.00

4.00

10 Linn Creek,

32

9

11. St. Joe

42

20

2,000

8

0.75

0.75

2.00

12. Granby

27

15

1,500

12

150

2.00

2.00

Mean....

...1.13

2.57

GR— 6

82 LEAD FURNACES AND PRODUCTS.

Size and Weight of Charge. — The mean area of the hearths of rever- beratories in the above list is 35.66 square feet ; on this hearth is charged an average weight of about sixteen hundred pounds of ore, which as far as can be ascertained, has an assay value of 78 per cent, metallic lead. The lead furnace (Flintshire) at Bagilt, near Holy- well, Flintshire, from the dimensions given by Percy,* has a hearth area of 90.25 square feet, and is charged with 2,352 pounds of ore (with draughtage calculated to cover the moisture of the ore,) with an assay value of from 75 to 80 per cent, lead (say 77.5.) A furnace of similar style, cited by Rivot,f has a hearth area of 86.5 sq. feet with a charge of one ton (2,240 pounds) of 78 per cent. ore. The Bleiberg furnace, which approaches more closely the ordinary air furnace in use in this State, both as respects size, and in regard to the method of work, has, according to Rivot,J a hearth area of 54.5 square feet, with a charge of 456 pounds, yielding, by fire assay, 65 to 72 per cent, metallic lead (say, 68.5.)

The fire boxes of the several furnaces named above are as follows :

Missouri Keverberatories 13.37 square feet.

Flintshire at Bagilt 38.25 square feet.

Flintshire (by Rivot) 9.79 square feet.

Bleiberg 6.84 square feet.

From which the following proportions between the areas of the fire box and hearth are established:

Missouri .-. • .1:2.(>

Flintshire 1:8.

Flintshire .' 1:9-.

Bleiberg 1:8.

Fuel consumption: In the treatment of one ton. of ore the Mis- souri air furnaces consume on an average 1.13 cords of wood. A cord of oak wood of the mixed varieties delivered to the furnaces and a& .usually piled, weighs about 3,800 pounds. In smelting one ton of ore there are, therefore, required very nearly 4.300 pounds of wood. The two examples of the English furnaces that we have selected require,, respectively, 1,333 and 1,050 pounds of good quality coal for the ton (of 2,000 Ibs.) of ore put in treatment. Karsten estimates that, in reverberatory effect, one part by weight of coal is equal to 2.6 parts by weight of good wood (probably too low an estimate for a compari- son between the good quality English coal and the imperfectly sea-

^Metallurgy of Lead, pp. 222, et seq. •^Traite de Metallurgie, II., pp. 319, et seq. $ Jitrf, pp. 299, et seq.

LEAD FURNACES AND PRODUCTS.

soned mixed woods furnished the furnaces in Missouri), on which basis the weights of coal named will be equal to 3,466 and 2,730 pounds of wood respectively. The Bleiberg furnace consumed 32,000 pounds of well seasoned fir-wood.*

In so far as the consumption of fuel to a given weight of ore treated is concerned, better results are obtained with the foreign furnaces than with those worked here, and in those furnaces, it will be remembered, the hearth areas are about eight times greater than the fire box areas. The yield of lead will also influence these results.

Labor: The table gives as a mean amount of labor required for the treatment of one ton of ore in the Missouri air furnaces, 2.57 days — skilled and ordinary labor both included. The two Flintshire fur- naces require of all kinds of labor, and for the ton of ore, 1.36 days, while the Bleiberg necessitates 3.98 days, this latter being increased by the fact that the residues are also worked up in the same furnace, and their treatment is included in the cost of the ore smelting.

The furnaces are, therefore, more expensive in labor, demanding nearly twice as much of this item of cost as the large English fur- naces, though no.t so much as the Carinthian, in which the whole method of treatment is shaped rather to economy of fuel than saving of labor. The Flintshire furnaces look rather to economy in expen- diture of labor than to saving in cost of fuel. To be in strict accord with the conditions surrounding metallurgical industry in this State, expenditure of fuel should be subordinated to expenditure of labor.

Furnace yield of ore: The average of the ore put in treatment and handled in the manner we have described, cannot have a furnace yield greater than 63 per cent, though this point is difficult to reach with much precision. One ton of ore would yield 1,260 pounds of metal against 1,560 pounds determined by assay to exist in it. The amount obtained is then about 80 per cent, of the assay value of the ore. A charge of 21 cwts. of good Flintshire ore yields about 14| cwt. of lead, of which 91 per cent, is obtained directly from the ore, and 9 per cent, from slag, etc., according to Percy, or 1,381 pounds to the nett ton, equivalent to 62.84 per cent, yield from the ore. The treat- ment therefore recovers 81.6 per cent, of the lead, which fire assay shows to exist in the ore. The example given by Rivot, shows a recovery in the reverberatory of 80 per cent, of the lead existing in the ore, while the Bleiberg furnaces give a 60 per cent result, corres- ponding to 87.6 of the assay value of the ore.

The loss in treatment, from all sources, in the several practices of reverberatory smelting named are 20, 18.4, 20 and 12.4 per cent, respec-

*The results are obtained from the several authorities mentioned, calculations being made to reduce to the ton of 2,000 Ibs.

84 LEAD FURNACES AND PRODUCTS.

tively, of the amount of lead which fire assay shows to exist in the several lots of mineral put in treatment. The Bleiberg practice in- cludes a residue treatment in the same furnace by the same workmen and is therefore much less than the other, and is hardly comparable. The others it will be seen differ but slightly among themselve, and may be, for all practical purposes, regarded as the same for both the ordinary Missouri air-furnace and the Flintshire furnaces.

The examples of English smelting show that the per centage of residue yielded by a charge of ore, range between llf and 25, with a mean of 17.3, and that the assay values of those so-called slags are between 40 per cent, and 55^ per cent, with a mean of 51 per cent., as determined by crucible assay. The mean composition of the twelve samples of residue, the results of the analyses of which have been given, on preceding pages, so far as the lead compounds are con- cerned, is as follows :

Lead sulphide.... 29.42 per cent.

Lead sulphate 2.89 per cent.

Lead oxide 39.74 per cent.

Metallic lead 56.88

These estimations having been made in the humid way are higher by about five per cent, than results which would have been reached by the most carefully conducted dry assays. The mean amount of lead in our slags, therefore, does not differ greatly from the average metallic content of the residue from the English reverberatories. Hence it may safely be assumed that the amount of residue drawn from the charge of our air-furnaces is about the same as that drawn from Flintshire, namely, about seventeen per cent, of the weight intro- duced.

These figures show that of the total lead value of our ores, 80 per cent, is recovered in thereverboratory furnance, 11.25 per cent, passes into the residue, from which, at those cases where slag-lead smelting practiced it is partly recovered as slag lead, and 8.75 per cent, is lost, chiefly in fume and in furnace bottoms.

So far then, in the common Missouri reverberatory practice, the results are equal to the best English examples, but they are not at- tained with the same regard to economy in labor and fuel. The dif- ference in these important points must be looked for either in the form of the apparatus used for treatment, or in the capacity of the workmen, for these can be the only variables in the treatment of simi- lar ores in different furnaces and with workmen of different energies.*

* This point is well illustrated by Moisenet. Traitment de la Galene au four Gal- lois, Ann. des mines, Tome 1, 1860.

LEAD FURNACES AND PRODUCTS. 85

Kepresenting the weight of a charge in pounds by c, the number of hours required for its elaboration by £, and the weight of ore treated in twelve hours, that is to say the activity of the furnace, by w, then w=I2 -^, and the following values will be obtained for w in the sev- eral furnaces we have been comparing:

Value Weight treated per

of w. man per 12 hours.

English 3795 1897

Missouri 1800 900

Bleiberg 475 237

The smelter at the English furnaces treats, therefore, in a given time, more than twice as much ore as the American and eight times as much as the German smelter. All this difference cannot be accounted for reasonably by the difference of energy of the workmen at the different localities, but must be looked for evidently in the construc- tion of the furnaces.

Examining the proportions existing between the hearth and fire- box areas of the different furnaces which have been put in compari- son, it will be seen that our air-furnaces have much less hearth sur- face in proportion to the surface of the horizontal section of the com- bustion chamber than any of the others. A remedy for the apparent difference between the working effects of the English and American smelter may be found in an increase of the size of the hearth till the ratio between the two areas approaches more closely that obtaining in the cases of the foreign furnaces, whereby the charge could be either ircreased in weight, or this remaining constant, a thiner layer would be spread over the sole. The effect of this would be more thorough oxidation and a shortening of this period as well as that of the reaction proper, by which the charge would be as thoroughly worked off in a shorter time, and the furnace activity be thereby increased. This view, though hypothetical, would seem to be warranted by those experiences cited elsewhere, and may therefore be worthy of atten- tion from those who may appreciate the importance of decreasing the expenditure for labor required for the production of lead. It is also strengthened by what is shown in the composition of the residues, these latter showing an average of 29.42 per cent, of lead sulphide or unchanged ore, and only 2.89 per cent, of lead sulphate, showing that oxidation has not been thorough, owing, possibly, to a too highly heated hearth and a consequent partial fusion of the ore. With such conditions rapid elaboration of a charge is impossible. Tookey's results* show for the residues or gray slag from the Flintshire furnace

* Percy, loc. cit., page 235.

86

LEAD FURNACES AND PRODUCTS.

0.9 per cent, sulphide, and 9.85 of lead sulphate. It may be added . that in these residues nearly all the silica was found to exist in combi- nation as a silicate decomposable by acid with the separation of gelat- inous silica. It is most probably in union with lead oxide, a condition which would imply considerable action of the charge on the furnace lining, also a result of the too elevated temperature of the hearth, for the average ores are hardly silicious enough to account for this silicate of lead.

There being so many other items entering into the total expenses of furnace operations, it is deemed inadvisable to attempt, with the data at hand, a summing up of the cost of treatment. The amounts of the two chief items, labor and fuel, have been indicated and will be found to be very close to the condition realized at the Missouri furnaces. The items of wear anol tear and interest are exceedingly variable, and besides could not be reached with even approximate accuracy.

Hearth Methods — Two classes of ore hearths are in use ; those with a single tuyere, and those larger and with three tuyeres, or, as we have distinguished them, the older and the newer patterns.

The accompanying statement of the. results of the illustration of hearth methods includes the (calculated) amounts of labor and fuel expended in the treatment of one ton of ore (2,000 pounds). In the case of the Valle hearths the fuel includes the estimated charcoal corresponding to one-twentieth of a cord of wood.

RECAPITULATION OF KESULT WITH HEARTH METHODS

NAME.

No. Tuy.

Charge — pounds.

Labor — days.

Charcoal per charge — bushels.

Labor per ton — days

Charcoal per ton- bushels.

Granby

3

3000

3

9.2

2.0

6 13

3

3000

3

15 0

20

10.00

3

3200

2.5

8.3

1.56

5.19

O'Brien

1

2000

3

9

3.0

9

HopGwell

1

2731

3

9

2.2

9

Perry

1

3000

3

10.0

2.0

6.6S

Valle

1

3500

3

9.3

1.7

5.06

Comparing together the results of the old and new forms it will be seen that the former consumes 5.84 bushels of charcoal per ton, while the latter requires 7.44 bushels. But this increased consump-

LEAD FURNACES AND PRODUCTS. 87

tion of charcoal which the three tuyere furnaces show , and which would be naturally expected, is offset by the diminished amount of labor, the new form requiring 1.85 days labor, against 2.22 days labor in the treatment of one ton ore in the hearth with the single tuyere. The items of fuel do not include any consumed for the blowing engines.

There are few data extant for comparing the results above given for the single tuyere American hearth, with those at any other local- ity in this country. The works on metallurgy contain statements of the cost of hearth treatment at Rossie, N. Y., which show a fuel con- sumption of 0.2 cord of wood per ton of ore, corresponding to a some- what greater number of bushels of charcoal than that given above.

The figures we have collected show a mean yield of the ore in all the hearths of about 67 per cent, of the ore put in treatment, which has probably an assay value of 78 per cent. The amount of lead saved is 86 per cent, of the assay value. The Mine la Motte results .give for the yeld of residue 13.5 per cent, of the ore treated, or 270 pounds weight per ton of ore. The average composition of these resi- dues we find to be as follows:

Lead sulphide 23.86 percent.

Lead sulphate 1.83 per cent.

Lead oxide ;.. 28.60 per cent.

Total Metallic lead 48.8

The total lead is the result of determinations, all made by humid methods, and are at least five per cent, excessive over the result's by fire assays, so that the assay value of the residues would be, say, 45 per cent. The slags from a ton of ore would contain 121.5 Ibs. of lead, equivalent to nearly eight per cent, of the total lead shown by assay to exist in the ore. This is partly recovered in those cases where slag treatment is resorted to. The loss from all other sources — (fume, dross, etc.,) is therefore four per cent, of the total content of metallic lead.

Comparing these results with those calculated for the existing reverberatories of the State, it is evident that, as far as the mere ope- rations are concerned, the hearth is somewhat less expensive both in labor and in fuel than the reverberatory. Taking the cost of these items at $2.75 per day for the labor, $2 per cord for wood, and 12 cents per bushel for charcoal, the costs per ton for ore treated, will be :

Labor. Fuel. Total

lleverberatory $6.97 $2.26 $9.23

Hearth 5.58 62 6,20

But it must be remembered that the hearth method entails addi-

88 LEAD FURNACES AND PRODUCTS.

tional expenses for labor and fuel for the blast, which may be roughly estimated at a total of $1.80 per ton of ore, which will increase the cost of treatment to $8. Further, the much more expensive charac- ter of the plant of the hearth, above that required for the reverbera- tory, will increase the aggregate by the greater item of interest. On the other hand, the wear and tear is less in the hearth, and the yield is greater.

In spite of these offsets, there is very little difference in cost of treatment or production now obtaining, and if improvements were made in the dimensions of the reverberatories, the advantages would be decidedly in favor of this method of treatment. This view is con- firmatory of that taken by Dr. Percy (in criticising the comparative results in treating similar ore in the reverberatory and the ore hearth at the Greenside mines in Westmoreland, England) who states: "The wear and tear in ore-hearths is certainly less than in reverberatory furnaces ; but probably insufficient to cover the considerable balance against ore-hearths, so that we may expect to see the former displace the latter in all but few localities, where coal cannot be got at mod- erate prices." *

While on this subject, it may be interesting to call attention to the results obtained by Mr. E. D. Peters f at the Mount Lincoln Works, Colorado. With a reverberatory, with a hearth 15 by 9-J feet, and with two and three-fourths ton of ore for a charge, the cost of treat- ment we find to be 1.11 days, and the fuel, 1.66 cords wood. It is note- worthy that the ore was more silicious than calcareous, and therefore of a character which, according to preconceived notions, was not well adapted to reverberatory treatment.

The cost of slag treatment has been shown to be about 0.4 day for the labor, 266 pounds of coke and 30 pounds of charcoal for the ton of residue treated, independently of the cost of the wages of the engineer and the fuel for the engine. With the same prices for labor and charcoal that have been assumed, and with a cost of twenty-five cents per bushel for coke, the items will aggregate $3.18.

For the ton of residues at the (English) Flintshire furnaces, Ri- vot's estimate of the special expenses are :

Workmen 1.907 days.

Coke 627 pounds.

Coal for blowing engine 367 pounds..

At the same rates for the first two items, the expenses will aggre- gate $9.64. The labor probably includes, however, that of the engineer

* Loc. cit., p. 285.

f Transaction Am. Inst. Mining Eng., vol. 2, pp. 310.

LEAD FURNACES AND PRODUCTS.

and fireman. The estimated cost of the proportion of the times of these added to the expenses above given for the Missouri slag furnaces will give a total of $4.28.

As was stated, the system practiced in this State is an improve- ment over that obtaining in the north of England; the expenses in treatment of the residues being scarcely half as great as those for the English method of work. The yield of lead is, however, greater in the latter than in the Missouri, this producing about 23 per cent, lead on the average, while that gives 35 per cent. The difference in the- cost is lessened when assessed on the ton of slag lead produced. The costs are then as $18.60 to $27.68.

This reduced cost in treatment will show that in the plan of resi- due treatment practiced in Missouri, the wastage of lead in the slag is more apparent than real. The value of the lead is more than com- pensated for in the reductions in the costs of labor and fuel, to say nothing of the additional expense of flux. It is probably more nearly in accordance with the conditions of our local metallurgy than any of the present plans of direct treatment of the ore.

The details we have given enable us to calculate with some approximate accuracy at least the special expenses attendant upon the complete treatment of a ton of ore, including the residue as well as those necessary to the production of a ton of metal, including that from the residue. These will be found to be as under :

Reverberatory treatment of one ton mineral $9 23

Slag treatment of 340 pounds residue 72

Total „ $9 95

The yield will be :

From the reverberatory 1260 pounds lead.

From the slag 78 pounds lead.

Total lead recovered 1338 pounds.

or 66.6 per cent, of the ore, equivalent to 86.8 per cent, (nearly) of the assay value of the lead. The cost of one ton of lead is therefore $14.88, exclusive of the general expenses of the establishment.

The apparent loss of lead from all sources, according to these cal- culations, is 13.2 per cent., while the real loss, taking into account the actual value of ore in lead, determined by exact analytical processes, cannot be less than seventeen per cent, of the metal. This difference between the real and apparent loss is certainly all assessable on vol- atilization, but does not cover the full wastage from that cause. The attention of smelting establishments in the State should be directed to this loss and more adequate means be taken to provide against it- At present the waste is almost entirely neglected in Missouri.

90 LEAD FURNACES AND PRODUCTS.

By including the cost of residue treatment, we are in condition to make a more just comparison of the costs of treatment in the Mis- souri air-furnace and the Bleiberg form, which it will be remembered includes a working of the slags in the same furnace. With the assumed prices for labor and fuel the aggregate of expenses for the Bleiberg furnace will be found to be $12.62 per ton of ore, yielding in the furnace 60 per cent., or twelve hundred pounds of metal. The cost of production is, therefore, $21 per ton of resulting metal. The yield is 87.6 per cent, of the assay value of the lead in the ore. Evidently the elaborate and close work of the Carinthian furnace, expending such an excessive amount of labor, is not adapted for profitable em- ployment in this State, and cannot compete with our present waste- ful system with existing high prices of labor, though relatively cheap fuel can be obtained.

These estimates confirm the views that have been advanced respecting the reverberatory system practiced in Missouri. It is evi- dent from them that all that remains to be done is to increase the activity of the air-furnaces, which result can be satisfactorily reached only by increasing the size of the hearths. If the reader will refer to the recent reverberatory experience in Colorado, noted in this sec- tion, he will find that the labor per ton of ore is reduced to 1.11 days, while the fuel is only 1.66 cords, by having a hearth with 142 square feet area, which accommodates two and three-quarters tons of ore at a charge. Obviously a step in the right direction is being made by the introduction in this State of iurnaces modeled more upon the type of the Flintshire or English reverberatories, which we have seen give such excellent results. The Granby furnaces of this pattern, the new furnace at the Des Loge works, and that at the Frumet, appear to us, on theoretical grounds, to be a decided advance toward greater economy of treatment, though it is to be regretted that, through want of data, we have not been able to examine into this matter as thor- oughly as the importance of the subject demands.

ADAPTABILITY OF MISSOURI LEAD TO CERTAIN INDUSTRIAL USES:

The character of the ores of lead and the metallurgical treatment that they receive, result in the production of a metal which experi- ence has shown is well adapted to the manufacture of white lead. Lead suitable for conversion into this irnpoitant product is usually denominated usoft lead"; it must be capable of being rapidly corroded, that is, of being converted into basic carbonate of lead, under the con- ditions to which it is exposed in the stack, and of yielding a product which is of pure white color. Commonty in the history of the white- lead manufacture in the eastern states, the preference has been given

LEAD FURNACES AND PEODUCTS. 91

to imported leads, more especially to those of continental Europe. These have generally resulted from three fining of more impure or work leads, incidental to the extraction of silver. The process now usually adopted for this latter purpose, consists in melting the silver-bearing Jead with metallic zinc, whereby the silver is largely alloyed with the zinc, from which it is separated by distillation or otherwise. The details of the process are not necessary in a report of this character ; but they result in the production of leads of remarkable purity, which have been and are still, deservedly in high repute among white lead corroders.

Missouri leads are not of a character to warrant any such treat- ment— not being as we have seen, argentiferous. Nevertheless they have given excellent results on corrosions, both in respect to degree of corrodibility and to character of product, and have been long used among white lead manufacturers in St. Louis. Since the beginning of the year 1875, they have also found their way into eastern markets, coming into successful competition with well established European brands, and in fact, largely displacing them. This has been effected in the face of difficulties arising from or encouraged by prejudice, and from the fact that, though the Missouri leads were generally of lower market rates, manufacturers are not disposed to change the routine of their process, or are fearful of destroying what may have been recognized as a distinguishing feature of their product.

Recognizing the value of Missouri lead as a raw material for white lead manufacture, the writer of this*report, as early as May 1875, called attention to the matter in the following introduction to a paper on the composition of Missouri leads :

For the purpose of White Lead corrosion, some of the brands of European leads have secured a prominence, and are preferred, not- withstanding their relatively high prices. How far this preference is justified by the inherent qualities of the lead, evidenced in the results of corrosion obtained, or how far it may be the result of a prejudice* perhaps, created and fostered by trade manipulations, are questions difficult of settlement. The imported and prized leads are generally the products of refining processes to which the Missouri metal cannot be economically submitted because unwarranted by a sufficient amount of silver. On the other hand, the established purity of the ores of the lead districts of Missouri should admit of the production of a metal which by a simple process of so-called refining and im- proving, or rather softening, ought to approximate at least to the purity of the much prized imported brands. The circulation, there- fore, of correct knowledge of the composition of the pig leads pro-

92 LEAD FURNACES AND PRODUCTS.

duced from the ores of the great lead area of the Mississippi Valley regions must be of value if they should be able to show that much of the prejudice against the domestic and in favor of the foreign lead, is ill-founded or is based only (as may be the case with white lead manufactures) on traditional results of corrosions obtained. On this point a recent writer on the metallurgy of lead* gives the following : "The best white lead, i. e., the whitest, was supposed by many to be made from what is known in the market as 'W. B. selected and re- fined pig lead,' (the initials being those of Walter Blackett, the pro- ducer, and now applying equally to the name of his successor, Went- worth Beaumont.) This pig lead is the produce of certain mines on the Greenwich Hospital estate, in the north of England, which are leased to Mr. Beaumont. It fetched a higher price to the amount of from 5 p. c. to 7| p. c. than any other pig lead. So great was the prepossession in favor of this pig lead for the manufacture of white lead, that attempts to persuade London manufacturers to make a trial of the best and purest soft lead from other sources were fruitless, notwithstanding it was offered at about 30 s. per ton, i. e., 7| p. c. less than W. B. lead. Commercial competition, however, seems at length to be uprooting prejudices which, as in the case in question, have probably no better foundation than traditional credulity. It is to be hoped that now-a-days the world is growing wiser, and will judge an article of manufacture by its quality and not by its pedigree. Many illusions connected with articles of manufacture have been dispelled, in recent years, with much gain to the public, and possibly it will be found that plenty of lead is produced in Great Britain and elsewhere,, quite as suitable for conversion into white lead as that bearing the mark CW. B. selected and refined.'"

Since the analytical results which were introduced by these re- marks were made public, the prejudice against our leads has disappeared very rapidly before a knowledge of their composition ; but it may not be out of place in a report of this character to go further into a con- sideration of this important subject.

Of the foreign metals present, copper, iron and nickel forming colored compounds may be regarded as those which may most seriously impair the color of the white lesrd. But it cannot be ad- mitted that the minute amounts of these metals which are present in any soft lead, or in any lead which would be selected by an experienced corroder, would be powerful enough to affect color to the unlimited ex- tent which has been claimed for them. Their potency is greatly over- rated in this respect. In fact the whole matter of impaired color of

* Percy's Metallurgy, p. 508.

LEAD FURNACES AND PRODUCTS. 93

corrison is one which is by no means settled. The rose tint frequently noticed was ascribed to copper oxide, and to iron oxide, but in 1869, W. Baker claimed that it should be ascribed to silver, which, if present to the extent of 1-13 of an ounce to the centner of the corroded lead, would tint the whole product of white lead.* Bannow and Kramerf ascribe the same coloring to the presence of lead suboxide formed by imperfect ventilation of the stack during the corrosion period. Lor- scheid,J to the same compound existing through insufficient carbonic acid in the stack.

The annexed table includes all the results of the analyses which have been given on the preceding pages, together with results of analytical investigations into the composition of some other American leads and a few produced at foreign establishments. The latter are all well known and favorite brands. The leads from Missouri furnaces, it will be seen, are of average purity with those others that are given. They contain no bismuth, but have the other foreign matters present in no greater amounts than the favorite brands.

* Phil. Magazine, May 1869, p. 324. f Jahresbericht fur Technologie, 1872. I Ibid. 1873.

LEAD FURNACES AND PRODUCTS.

TABLE showing the Composition of Commercial Leads produced in Missouri^

BRAND.

FURNACE METHOD.

ANALYST.

Granby

Granby

Lone Elm

Bade County

Pioneer

Eagle

Buttalo

Star

Wyan Spring

Bond's

Linn Creek

St. Joe

Frumet

Frumet

Granby

Hopewell

Perry

Valle fVal!6 Furnace;

Rozier (Valle Furnace)

Mine la Motte

Granby

Phoenix (Vall6 Furnace)

Mine la Motte

St. Louis Smelting and Refining Co.

Pittsburg (a)

Reverberatory (Flintshire) Reverberatory (ordinary) . .

Hearth. . .

Cupol

Lautenthal (ft)

Lautenthal (c)

Altenau (d)

Pontifex & Wood

W. B —best selected

Stolberg

Eschweiler Company

Pirath & Jung, Commern . .

Real Compania, Asturania. . Herbst & Co. , Call— 1867. . . . Mechernich— 1869...

Refined from Territorial Work Lead Refined from Territorial Work Lead

Refined from Clausthal Lead

Refined from Clausthal Lead (1870) . ,

Refined from Clausthal Lead (1871) .

This Report

This

Cha ivenet and Blair

Report

Dr. Wnth

Hampe

Schollmeyer

Hampe

Laboratory at Clausthal,

Fresenius.

a— Cited by Eilers, Trans. Am. Inst. Mining Eng.,Vol. Ill, p. 322. 6 and c— Cited by Eilers, Raymond's Report, 1874, p. 445. d — 16., p. 454 — produced by poling lead obtained in the treatment or rich foreign silver ores and dressed lead ores of the Upper Harz.

LEAD FURNACES AND PRODUCTS.

95

together with Results of Analyses of some other Domestic and Foreign Brands.

1

Antimony..

Arsenic ....

Bismuth....

(

°J

§

N

5' ,

Nickel.

Cadmium .

Other matters. .

99.95267 99.91677 99.96340 99.99247 99.97469 99.99320 99.98722 99.96359 99.97786 99.98078 99.95737 99.93124 99.94826 99.95700 99.96905 99.97408 ^9. 97291 99. 94548 99.91019 99.96996 99.90756 99.74526 99.89337 99.91813

99.99844

99.983573 99.983139

99.976719

99.91360 99.95200 99.95000 99.94060 99.98329

99.98597 99.98740 99.99474

0.00077 0.00077 0.00266 Trace 0.00347 Trace 0.00281 0.00513 0.00048 0.00495 0.00639 0.00675 0.00007 Trace 0.01085 0.00803 0.00520 0.00214 0.00184 0.00119 0.04976 0. 13365 0.00119 0.00538

0.00051

0 .001184 0.005698

0.005743

0.00320 0.00590 0.00500 0.00210 0.00921

0.00133 0.00450 0.00118

0.01640 0.01122 0.00027 Trace Trace 0.00313 Trace 0.01086 0.00338 Nil 0.01423 0.00183 0.00004

6'66i24

0 00583 0.00674 Trace 0.00925 0.00034 0.00101 0.01556 0.00125 0.00066

0.01210 0.05091 0.00463 0,00448 0.00346 0.00820 0.01024 0.01376 0.01002 0.00556 0.01511 0.06394 0.04399 0.04100 0 00780 0.00585 0.00409 0.04165 0 03742 0.01999 0.02965 0.09323 0.08544 0.02457

0.00007

0.000954 0.001413

0.002475

0.07580 0.03180 0.03830 0.05010 0.00268

0.00057 0.00510 0.00234

0.00029 0.00080 0.00025 0.00177 0.00100 0.00029 0.00114 0.00029 0.00057 0.00084 0.00043 0.00405 0.00179

6! 00646 0.00219 0.00190 0.00326 0.00615 0.00345 0.00029 0.00525 0.00564 0.00210

0.00042

0.000500 0.000460

0.001000

0 .00200 0.00500 0.00250 0.00440 0.00275

0.00040

0.01711 0.01582 0.00777 0.00128 0.00496 0.00461 0.00556 0 00462 0.00428 0.00411 0 00376 0.00137 0.00282 0.00200 0.00367 0.00145 0.00436 0.00453 0.02497 0.00248 0.00718 0.00470 0.00334 0.00819

Trace

0.004930 0.002289

0.003272

0.00220 0.00170 0.00240 0.00080 0.00121

0.00124 0.0520 0.00090

0.00066 0.00090 0.02071 Nil 0 00517 0.00057 0.00136 0.00090 0.00139 0.00181 0.00136 0.00082 0.00240 Nil Trace 0.00156 0.00598 0.00294 0.00118 0.00164 0.00180 0.00235 0.00458 0.00493

0.00038

0.000361 0.000834

0.000140

0.00320 0.00370 0 00180

Trace 0.00281 0.0031 Nil 0.00125 Trace 0.00115 0.00085 0.00203 0.00195 0.00135 Trace 0.00063 Nil 0.00087 Nil Nil Nil Nil 0.00095 Nil Nil 0.00519 0.00045

II

:;:::::.

:;::.'.':'.

'6.'66296

6. '63559'

( Sulphur ( 0 00018

0.008498 0.005487

0.009580

Trace

0.000680

0.000196

Trace

( Chlorine ^ 0.000875

Trace Trace

0.00200

O.OOC08

0.01041

( Trace ) 1 Ni. and Co. ( 0.0010 '

0.00075

$ Trace 1 Co. Mn. $ Trace \ Mn.

Trace

96 LEAD FURNACES AND PRODUCTS.

It is not unreasonable to believe that the cause assigned by Messrs. Bannow and Kramer, or something analagous to it, is adequate to account for the impaired quality — much more so than are the minute quantities of the foreign metals — and that most cases of tinted cor- rosions made from soft leads may be referred to internal conditions of the white lead stacks. If this view be correct, then much of the virtue claimed for extraordinary freedom from impurities disappears so far as the color of the white lead is concerned, or if still existant, finds its cause of existence in trade prejudices or manipulations, which deterred manufacturers from changing to any lead which differed, however slightly, in comp.osition from that which they had been accustomed to employ.

The maximum amount of these coloring metals which may exist in a lead without impairing the quality of the white lead made there- from, has not been fixed, but any lead, which would yield a product colored, say, greenish from copper compounds, would not be a soft or corroding lead. Doubtless this limit is passed in the slag leads of Missouri, (mean amount of copper, .06944 per cent.), but it is not reached in the reverberatory leads from southwestern and central ores, (with .01329 per cent, copper) for many of these have been prac- tically tried, and besides their mean amount of copper is not much greater than the mean result of six leads analyzed by Fresenius (with .01046 copper) all of which are recognized and em ployed as soft corrodable leads. It the one gives an uncolored product, then the other set may reasonably be expected to give the same under similar conditions of corrosion.

The result of analysis of the lead of the St. Louis Smelting and Refining Company prepared in refining the work, lead from territorial ores, shows upwards of 0.02 of copper, and this lead has given most satisfactory results with both St. Louis and eastern corroders.

Instances of practical experiences such as these, must carry con- viction that either these small per centage of certain metals do not work with prejudice to the color of the white lead, or that preposses- sion in favor of certain brands of lead has been created and sustained by commercial operations, and are not warranted by sufficient dif- ferences in composition.

Differences in favor of or against a brand of lead, when such small amounts are taken into consideration, may readily arise from errors inherent even in the most carefully conducted analytical investigations into their composition, or from variations in drawing samples for analysis. On this last point Schweitzer* found in the

* American Chemist, June, 1876 ; p. 457.

fcEAD FURNACES AND PRODUCTS. 97

same pig of lead, by cupelling, seventeen samples from different parts, amounts of silver ranging between 79.83 ounces to the ton and 104.93 ounces.

The other foreign metals may affect the corrodibility of the lead but on this score the knowledge with regard to the small amounts existing in soft leads is but little more extended or certain than in respect to the coloring power of the metals already named. Much that has been ascribed to difference in composition of the leads corroded is, without doubt, to be traced really to conditions of tem- perature and of the atmosphere in the stacks. These are matters upon which there is little if any informatioii. It is within the expe- rience of every manufacturer that differences in the percentage of metal corroded are as great for the same metal in different or even in the same stack as for different leads in separate corrosion heaps. Till more knowledge is obtained in regard to the thermal conditions of cor- rosions and the composition of the atmospheres of the stacks, this point must remain in obscurity, or be — unphilosophically it would seem — charged to minute variations in the amounts of a given foreign metal in the lead.

Antimony is generally regarded as prejudicial and bismuth favor- able to rapid and thorough corrosion. The latter is rapidly oxidized if intimately mixed with the lead, but if concentrated in parts of the buckles (as may happen in casting) it oxidizes slowly itself, and pre- vents or retards further corrosion of the lead.* The presence of bis- muth (0.03559 per cent.) in the lead of the St. Louis Smelting and Kefining Company may account for the favor with which this lead has been received, and also for the prejudice in favor of certain European brands.

On the other hand, the extended and carefully conducted experi- ments of Hampe with Hartz and other brands of lead of recognized purity, and with prepared alloys of bismuth and lead, simultaneously corroded at the Hartz Lead Works at Osterode, do not support this view of this action of bismuth. Neither do they substantiate the opinion generally advanced that the bismuth compounds impart a tinge of gray to the white lead, which, though disappearing on grinding and levigation, nevertheless, cause the white lead to turn yellow in the dark.f

Some diversity of opinion exists concerning the action of anti-

* Endeman on Bismuth in lead in the Manufacture of White Lead. American Chemist, June, 1876.

f A translation of Hampe's paper (by Prime) can be foand in American Chemist, June, 1875.

GR— 7

LEAD FURNACES AND PRODUCTS.

mony. This metal is generally regarded as retarding corrosion in white lead stacks. Hasenclever f shows that it has such effect in the lead pans used for evaporating sulphuric acid. The rapid wear of such pans is due to the greater purity of the metallic lead ; antimo- nial.lead lasts much longer. On the other hand, common experience with metallic constructions shows that small amounts of foreign met- als hasten oxidation.

On the whole, the subject of the conversion of lead into white lead by the so-called Dutch method is but little understood, and many so-called explanations of unsatisfactory results are the vaguest hypotheses. The experiences of eastern corroders have been fully as satisfactory with the Missouri soft leads as. with European leads longer in use.

Manufacturers generally hold that the residual blue lead, or ker- nels remaining uncorroded, contain the foreign metals of the lead in increased amount. This reputed concentration has not been estab- lished, and the matter is one not easily settled. Hampe writes con- cerning this : " Finally, with regard to the frequently imputed en- richment of the foreign metals in the metallic residue (the so-called lead kernels) obtained in the preparation of white lead, it is impossi- ble to give a definite answer to this from the following analyses. It must, however, be borne in mind that such pure leads are not well adapted to settle this question, since the differences are so small that it is impossible to say whether they are essential, or whether they are due to the uncertainty caused by the taking of samples for analysis from the residues. An enrichment of the bismuth in the finely divided lead was found only in the bismuth alloys after separating the residues from the white lead by washing."

The result of our analysis of a sample of unwashed white lead manufactured in St. Louis is given below, (II), as well as the compo- sition of the lead from which it was corroded, (I), and of the blue lead or kernel separated from the same (III). The foreign metals only are given.

Missouri Lead and Products,

I. II. III.

Arsenic 0.00019 None. 0.00217

Antimony 0.00198 0.00076 0.00158

Silver 0.00045 0.00034 0.00050

Copper 0.00479 0.00926 0.01381

Iron 0.09020 0.00085 0.00315

Zinc , 0.00142 0.00035 0.00770

Nickel... 0.00047 0.00007 0.00055

f Berg and Huettenmann. Zeitung, Nov. 30, 1S72 ; quoted by Hampe (as above.)

LEAD FURNACES AND PRODUCTS.

Some of the results obtained by Hampe in the experiments above alluded to, are appended for comparison.

LAUTKNTHAL PRODUCTS (Hampe.)

I. II.

Oxidation Kernel from Original. White Lead. Oxidation.

Bismuth . 0.008498 0.006276 0.011091

Copper 0.000954 0.000431 0.001149

An&tnony 0.001184 0.000903 0.001334

Silver ; 0.000500 0.000500 not est.

Iron 0.004930 0.000728 trace.

Zinc 0.000361 0.000128 )

Cadmium) t t krace.

Nickel / Crace' j

SILKSIAN PRODUCTS (Hampe.)

Copper 0.0012 0.000566 0.000938

Bismuth trace. trace. trace.

Cadmium 0.00046 0.000360 0.000500

Antimony..... 0.00131 0.000444 0.001388

Silver 0.000166 0.000130 0.000166

Iron 0.00120 0.000903 0.000360

Zinc 0.00035 0.000257 0.00031

MECHERNICH PRODUCTS (Hampe.)

Bismuth 0.00022 0.000197 0.00024

Copper 0.00051 0.000408 0.000411

Cadmium 0.00037 0.000200 0.000450

Antimony. 0.00320 0,002218 0.00310

Silver 0.00032 0.000300 0.00038

Iron,. 0.00075 0.000937 0.000634

Zinc 0.00052 0.000337 0.00020

WHITE LEAD MANUFACTURE IN ST. Louis. — The census of 1870 makes no mention of this industry in St. Louis, though the business had then attained such magnitude that the value of the product is estimated by Mr. Cobb to have exceeded one and three-quarter millions of dollars. In 1875 the production was, according to the best estimates, 11,200 tons, an increase of about ten per cent, over that of 1874. According to the reports of the St. Louis Exchange, the white lead industry in 1875 had the following status in St. Louis :

Number of establishments 6

Capital invested , $2,033,000

Cost of raw materials 1,196,000

Value of product 3,292,500

Litharge and red lead or minium (oxides of lead) are incidental

100 LEAD FURNACES AND PRODUCTS.

products of the white lead establishments. They find consumption in a number of industrial operations, notably in the manufacture of glass and in connection with the painter's trade.

For glass-making purposes, the lead oxides must be as free as possi- ble from those foreign oxides which have coloring properties, especially oxide of copper. In the English markets the red-lead from Snailbeach metal finds preference among glass-makers, and brings, by five per cent., a higher price in the market. It contains from 0.0021 to 0.0065 of copper, the mean of five results by Percy, being 0.00492 per cent. No nickel or cobalt were detected, though especially sought after.

The following determination of the amounts of foreign metals in a sample produced in St. Louis, from Missouri lead, will be of interest in this connection as well as of value as collateral testimony bearing on the questions of the amount and effects of the impurities in Mis- souri soft leads :

Foreign Metals in Red Lead from Missouri Metal.

Per cent. Iron 0.10640

Zinc 0.04460

Copper 0.00207

Antimony 0.00920

besides traces (in one'hundred grammes) of arsenic and cadmium.

The growing favor that Missouri soft lead is finding among the corroders of the eastern cities is shown by the fact of the increase of shipments of lead eastward during the last three years. In 1873 the shipments exceeded those of 1872 by 153,178 pigs; 1874 showed an increase in the same direction over 1873 of 2,498 pigs, while the amount of 1875 exceeded that of 1874 by 102,135 pigs.

Lead for Mechanical purposes : Mr. Henry Cobb* estimates that from 1858 to 1873, the St. Louis shot tower, produced $9,000,000 worth of its product, with an annual production of nearly f 600,000.

According to the same writer, there are two establishments for pipe and sheet lead in St. Louis, yielding products with an annual value of $200,000.

While for mechanical purposes, such extraordinary purity of the lead is not expected, yet, excepting for certain special alloys, (solders, type metal, shot,) the most satisfactory results are, of course, realized by leads of high grade. The t question of the corrodibility of lead pipe and the influence on health and comfort by the water it conducts, are intimately connected with the purity of the lead. Dr. Paul Schweitzerf

^Appendix A— Broadhead's Report, page 684. f American Chemist, June, 1876.

LEAD FURNACES AND PRODUCTS. 101

of the University of Missouri, found in one gallon of filtered water, which had stood in lead pipe for one month — the water being rain water, collected in zinc-lined tank :

1.079 grains metallic zinc. 0.537 grains metallic iron. 2.503 grains metallic lead. 0.082 grains metallic copper. 0.049 grains metallic arsenic.

The pipe was evidently made from an inferior quality of lead.

The purest soft lead obtained directly from the ores produces the sheet lead best adapted for sulphuric acid chambers, resisting corro- sion better, and being, therefore, more durable. The soft lead is gen- erally selected for sheet purposes ; hard leads are preferred by manu- facturers for making pipes — antimony being sometimes added. What grounds, beyond prejudice, are held for such practice cannot be given.

THE ZINC INDUSTRY

OP

MISSOURI.

ZINC INDUSTRY OF MISSOURI.

The distribution of the ores of zinc in Missouri may be regarded as co-extensive with that of the lead ores, especially in the south- western and southeastern regions. Three mineralogical species con- stitute the great bulk of the ores, viz : Sphalerite or blende, cala- mine and Smithsonite. The ratio of the annual production of these by the Missouri mines, may be estimated to be as follows : Blende : calamine : Smithonite=100 : 138 : 130. The blende is produced chiefly by the mines of Jasper county, and in less amount by those of Newton ; the calamine ores by Newton, Dade and the southeastern region, in the order of abundance, while Dade county leads in Smith- sonite ores, followed by the southeastern lead mines.

SPHALERITE (Glocker), commonly called blende, and by the miners u black jack," is zinc sulphide, and contains by theory, 67 per cent, zinc and 33 per cent, sulphur.

Its crystalline forms belong to the isometric system with a dodec- ahedral cleavage. Frequently it ie compact and massive; sometimes fibrous and radiated; occasionally in botryoidal and other imitative shapes.

The colors are commonly brown, yellow and black, and occasion- ally green. When pure, yellow or white. Hardness from 3.5 to 4. Specific gravity 3.9 to 4.2. A cubic foot of solid blende, therefore weighs from 243 to 262 pounds.

The southwestern lead mines furnish, commonly, either a coarsely crystalline variety, with broad cleavage faces and of either yellowish or brown color, occasionally dark and nearly black ; or a granular variety, frequently of an adamantine lustre, and with a light yellow or brown, and not infrequently a red color.

In the central region sphalerite has not been found in sufficient quantities to have become a commercial article. It is there generally noticed, according to Schmidt,* as dark green, yellow or red crystal- line specl -j or as agglomerations of crystals between broken chert

* Broadhead's report, page 508.

106 ZINC ORES AND PRODUCTS.

(at the Eureka diggings, Cole county), or surrounds by barite (Coffin Springe, Morgan); as well-developed twin-crystals, translucent and of an amber yellow color, in black clay (Stacker's digging?, Morgan), and with galenite in contact with barite (Collins7 diggings, Cooper.)

Three varieties of sphalerite are admitted by Dana. These are: (1) — The ordinary, containing little or no iron ; colors, white to yel- lowish brown, sometimes black; (2) — Marmatite, the ferriferous variety, with a dark brown to black color, and with the proportion of the iron sulphide to the zinc sulphide, ranging from 1 to 5 up to 1 to 2; (3) — Przibramite, a variety carrying cadmium, always less, how- ever, than five per cent, in amount.

The following are analyses of sphalerite from Missouri localities :

I. II. III. IV. V.

Zinc 61.934 61.963 64.67 65.920 64.870

Iron 0.788 0.588 053 0.320 0.370

Cadmium trace none 0.509 0.723

Copper 0.043 none

Antimony 0.002 none .........

Sulphur '. 31.269 not est. not est. not est. not est.

Calamine 3.603

Gangue 2.552 not est. 2.05 0.25 1.41

No. I— From Newton county, analysed in this laboratory ; con- tained some intermixed calamine which was calculated from the silicic acid, (see Report A, p. 15.) II — From Jasper county. Ill, IV and Y analysed by Chauvenet; first, from Bellew shaft, Granby; second, from Porter's diggings, Joplin ; third, from Leadville.

Blende is usually silver bearing. If it occurs in association with galenite, there is commonly more silver in the sphalerite than in the galena. Malaguti and Durocher's,* researches show that most blendes contain small amounts of silver, up to 0.88 per cent., which cannot originate in the associated galenite. The Missouri blendes are not more argentiferous than are the galenas. Blendes found in gold-bear- ing districts, and even elsewhere, are auriferous to a greater or less extent.

CALAMINE (Smithson) is hydrous zinc silicate, with the following theoretical composition: Silica, 25.0; zinc oxide, 67.5, (containing metallic zinc, 44.2); water, 7.5.

Its common crystalline forms are hemihedral forms of the ortho- rhombic system. More frequently granular and massive ; also fibrous, mammillated, botryoidal and stalactitic. Frequent colors, white and yellowish and brown ; lustre, vitreous ; hardness, 4.5 to 5. Specific

* Annales des Mines, 1855.

ZINC ORES AND PRODUCTS. 107

gravity, 3.43 to 3.49, a cubic foot of the solid mineral, therefore, weigh- ing from 214 to 2x8 pounds.

The mineral is decomposable by the mineral acids, the silicic acid separating as a gelatinous mass.

The following are the results of analyses of calamine from locali- ties in this State :

I. II. III. IV. V.

Silicic acid 25.489 27.51 26.83 23.32 24.264

Zinc oxide 66.813 63.05 66.37 67.15 66.347

Ferric oxide 1.114 1.22 0.65 0.61 1.785

Lime trace. 1.21 trace 0.078"

Water..., 7.502 7.10 6.46 8.59 7.705-

100.918 100.09 100.31 99.57 100.179-

Metallic Zinc 53.62 50.37 52.97 53.95 53.25

I. By 0. R. Winters in this laboratory ; II, III and IV, by Chau- venet, (Broadhead's Report, page 393.) All the specimens analyzed were of the fine-grained, sub-crystalline variety, mixed with streaks of the crystalline variety, and were all from shafts at Granby. Y, from Yalle diggings, analyzed under my instruction by L. R. Grabill.

SMITHSONITE (Beudant,) chemically, is zinc carbonate, and has the following theoretical composition: zinc oxide, 64.8; carbonic acid> 35.2. The zinc carbonate is generally replaced by more or less of the isomorphous compounds, ferrous carbonate, manganous carbonate, calcic carbonate and magnesic carbonate. The pure mineral would contain by theory 51.6 per cent, metallic zinc.

When crystallized its forms belong to the hexagonal system. Its common modes of occurrence are as earthy masses, stalactitic, crys- talline incrustations, reniform or botryoidal. Color, white, often with a grayish or greenish tint; more commonly brownish, owing to the presence of ferric oxide resulting from the oxidation of ferrous carbo- nate.

Hardness, 5; specific gravity, 4 to 4.45. A cubic foot will weigh from 250 to 276 pounds.

Several varieties, depending on differences in amounts of foreign carbonates are recognized, but the separation of the varieties is not very complete or definite. The following are given by Dana: (1) Con- taining less than four per cent, of any other carbonate and without copper ; (2) ferriferous, containing more than twenty per cent, of fer- rous carbonate (zinceisenspath; the capnite of Breithaupt) ; (3) man- ganiferous, containing upwards of five per cent, manganous carbo- nate ; (4) cupriferous, (the Herrerite of Del Rio) a specimen of which from Abarradon, Mexico, gave GenthT 1.48 of cuprous carbo-

108

ZINC ORES AND PRODUCTS.

nate, and 93.74 of zinc carbonate, besides manganous, calcic and nesic carbonates.

The following are the results of analysis of some specimens Missouri :

I. II. III. IV.

Zinc carbonate 83.000 93.440 97.60 98.057

Ferrous carbonate 1.932 4.040 none.

Calcic carbonate 0.803 1.525 0.525

Magnesic carbonate 0.861 0.454 0.489

Ferric oxide 3046 0.800 1.21 none.

Alumina 2.573 0.261 none.

Silica 7390 0.477 1.22 0.902

Water.... .. 0.165 nil. nil. nil.

mag- from

V.

93.87

1.04

2.28

.70

2.09

.34

Metallic zinc....

100.277

48.618

100 03 50.37

99.973 100.32

No. I, from a shaft in Dade county, 12 feet below the surface, ana- lyzed in this laboratory by Mr. Jas. A. Pack; No. II, from same shaft at 35 feet depth, analyzed in the laboratory by A. H. Ohmann-Dumes- nil : No. Ill, from Hardshaft diggings, Granby, by Ohauvenet, (Broad- head's Report, 394;) No. IV, white, massive, from Taney county, by the writer; No. V, from Washington county, Valle mines, by the writer.

VI. VIII.

Zinc carbonate 90.081 89.538

Ferrous carbonate 0.059 0.101

Calcic carbonate 2.230 3.343

Magnesic carbonate 3.001 2.736

Ferric oxide \ o89o .» K9~

Alumina } 3'828 3'52'

Silica 0.436 0.600

Water

Zinc sulphide 0.597 0.961

100.233

VIII.

90.287 2.594 2.030 2268

1.467 1.492

IX.

91.557 0.656 2.557 2.318

1.389

trace. 1.086

Metallic zinc.

47.23

100.806 47.20

100.138 47.02

99.555 47.62

YI, from Hopewell, Washington county ; VII, from Mine la Motte ; YIII, from St. Joe mines, analyzed in this laboratory by W. R. Brown ; IX, from Granby, contains a little hydrozincite intermixed.

HYDROZINCITE (Kenngott,) or hydrous zinc carbonate, contains : zinc oxide, 75.3, (metallic zinc, 60.4;) carbonic acid, 13.6 ; water, 11.1. Though noticed at a number of Missouri localities it is, so far as quan- tity is concerned, of very subordinate importance as an ore of zinc. It is found at the Crabtree diggings (Granby) containing calamine;*

*Schmidt loc. cit,, page 394.

•V ZINC ORES AND PRODUCTS. 10&

and Gagef notes its occurrence at the Valle mines as an incrustation on Smithsonite.

This mineral is the zinc-bloom of some writers and the Marionite of Elderhorst, who notesj its occurrence in Marion county, Arkansas-

The following two species of zinc-bearing minerals are found in small quantities, but are of no significance from a technical stand- point:

BURATITE, a hydrous zinc carbonate containing copper oxide, (zina oxide, 44.7 ; copper oxide, 29.2 ; water, 9.9 : carbonic acid 16.2=>100,) is found as a coating on zinc ores, at the southwestern mines, notably at those of Oronogo, Jasper county.

GOSLARITE is found in solution in the mine waters from Oronogo,. resulting from the oxidation of sphalerite (see Report A, page 25.)

The following species, which at some localities are important sources of zinc, have not been noticed at Missouri localities :

Zincite (Haidinger): Zinc oxide, contains by theory, 80.26 per cent, metallic zinc.

Frankliniie (Berthier): Is composed of ferrous, manganous and zinc oxides combined with ferric and manganic oxides with from 17 to 25 zinc oxide. It occurs abundantly in association with the last named species at Stirling Hill and other localities in northern New Jersey.

Williamite (Levy): Is zinc silicate with 72.9 per cent, zinc oxide (== 58.5 metallic zinc) and 27.1 per cent, silicic acid.

GENERAL METALLURGY OF ZINC.

The fact that metallic zinc volatilizes at a temperature below that which is necessary to reduce zinc oxide, renders all methods for its extraction necessarily those of distillation, for it must be obvious that under such condition?, collections of the metal by liquification or fusion is impossible.

The reducing agent employed in practice is carbon, in the form of coal dust. The products of the reduction are, therefore, mainly carbonic acid and zinc vapor. At a temperature slightly below that at which zinc vapor may be condensed into liquid metal, the carbonic acid may act as an oxidizing agent on the zinc, producing carbonic oxide and zinc oxide again. Hence, to prevent the zinc from revert- ing to the condition in which it existed in the retort, viz : Zinc oxide> it is necessary to conduct the vapor into a suitably cooled receiver, which must be of small proportions in comparison with the volume

fBroadhead's Report, 610.

JFirst Report, Geol. Survey, Arkansas, 1858, pp. 153 and 154.

110 ZINC ORES AND PRODUCTS.

of the retort .or apparatus in which the reduction and volatiliza- tion of the zinc takes place. By properly proportioning the size of the condenser or receiver, the amount of reproduced oxide of zinc may be reduced to a minimum, though in practice some is always •produced.

Carbonic acid is a necessary product of the reaction which forms the zinc vapor, and as it is in great volume, objectionable in so far as it may, at the proper temperature, reoxidize the zinc, e,ffort should be made in practice to reduce its amount as nearly as possible to that which will be formed by the reduction. If, therefore, the ore contains carbonic acid it should be submitted to a preliminary cal- cination (in a kiln or a reverberatory furnace.) Water also oxidizes zinc vapor, at certain ranges of temperature, so that a calcination is also advantageous in order that the loss of zinc by reoxidation may be reduced to the minimum possible in practice.

In the case of blende ores it is necessary to submit the ore to a preliminary oxidizing roasting to convert the zinc sulphide into zinc oxide. In such a roasting zinc sulphate is always produced, and as this compound requires a bright red heat for its decomposition (into .zinc oxide and sulphuric acid) the expenditure of fuel in such roast- ings is sensibly increased. While blende ores are richer in zinc than are the oxidized ores (excepting zincite) their treatment is more expen- sive than is that of the latter, and they must therefore rate at lower price in the market than the calamine or smithsonite ores. Kerl states that at Borbeck and Oberhausen 128 pounds of coal are re- quired to roast sufficient blende to produce one hundred pounds of zinc, while for the calcination of enough calamine ore (mixed silicate and carbonate) to produce the same amount of metal only 13 to 15 pounds of coal are consumed.

The distilling and condensing vessels are made of refractory clay, which must be of high quality. As these vessels are subject to a some- what rapid wear through scorification and accidental breakage, an abundant and convenient supply of good clay is necessary to all zinc establishments. In fact the quality of the clay and its abundance influence to no slight extent the minor characteristics of the zinc extraction processes.

All the methods employed in practical extraction are based on the general principles already enunciated. The variations are in the forms of the apparatus and the furnaces induced by local considera- tions, such as the relative values of ore, coal and clay and the greater or less skill of the operatives. Three methods are recognized, deriv-

ZINC ORES AND PRODUCTS. Ill

ing their names from the countries in which they have been most successfully conducted. They are,

The English method. The Silesian method. The Belgian method.

The first is not so extensively practiced as formerly, having been supplanted by the others. The Belgian method with minor modifica- tions is employed in this country, and is therefore the only method which need be considered in this connection.

In this plan of treatment the distilling vessel or retort is cylin- drical and closed at one end. The usual dimensions are as follows:

Interior length 39^ inches.

Interior diameter 6J inches.

Thickness of walls 1J inches.

Thickness of bottom 2£ inches.

Capacity in cubic inches 1294.

A number of these retorts are arranged in rows in a furnace in such a manner that the open end slopes slightly downwards and out- wards. The combustion chamber of the furnace is fed with coal for the production of sufficient heat around and in the retorts to produce the temperature necessary for the reducing action of the carbon on the zinc oxide above mentioned, an intimate mixture of the calcined ore and coal (both in the state of powder) having been introduced through the open end of each retort. The lower row or the lower two rows of retorts are usually kept empty during the working of the furnace, as they are in position to receive too much heat. The retorts thus used to break the heat are technically called " can- ons." The upper rows of retorts, where the temperature is less, is charged usually with mixed coal and the dross and other products of the works rich in zinc. The furnaces are commonly built back to back in blocks of four.

The retorts are charged with a mixture of the calcined ore, two parts; with non- caking coal, one part. About forty pounds of the mixture constitutes a charge for each retort. After the charging, the receivers or condensers are attached to the open or outer end of the retort and properly luted. The receivers are of clay and have the form of the frustum of a cone, with the following dimensions :

Diameter at base 3| inches.

Diameter at top 2 inches.

Perpendicular height 14| inches.

Thickness of walls, from l^to f inches.

112 ZINC ORES AND PRODUCTS.

The capacity of the receivers, calculated from these dimensions, is about eighty cubic inches, so that the volumes of the retorts and the receivers are to each other as 16 to 1. The object of the relatively small condenser, as before stated, is to reduce the oxidation of the zinc vapor by the carbonic acid, to the smallest possible limit. Some zinc oxide, however, forms, and most of it is collected by attaching to the small or outer end of the reseiver, sheet iron cones, tapering to a small opening, which are known as prolongs.

The charge is worked off in twelve hours, when the receivers are detached, the residue withdrawn from the retorts and a fresh charge introduced. The upper retorts, or those charged with the rich zinc dust and dross, and situated in the less highly heated parts of the fur- nace, are charged but once in twenty-four hours.

The wear of the retorts adds very considerably to the expenses of zinc production by the Belgian methods. It is customary to estimate that the consumption of raw materials is, for ore^ 35 per cent.; for coal, including both fuel and the reducing agent, 50 per cent.; and for clay, 15 per cent. These figures are not widely different from those obtained in practice with careful management, and will show that the average life of a retort cannot be much longer than twelve days, or, say through from twenty to twenty-five charges.

The durability of the distilling vessels is largely influenced by the character of the ore put in treatment. Oxide of iron and oxide of lead cause more rapid wear of retorts, from their disposition to form, at high temperatures, fusible compounds with silica. Proper mixing of acidic and basic ores will obviate this difficulty, to some extent, in the case «of the iron compounds; lead is prejudicial to a greater extent, and its injurious effects are not so readily controlled.

The character of the ore, in respect to the presence or absence of certain foreign matters, influences also the character of the metallic zinc produced. Among the substances which operate injuriously in this way, may be named: arsenic, antimony and lead.

ZINC PRODUCTION IN MISSOURI.

The inauguration of the manufacture of speltre, or metallic zinc, dates back only to 1867, it having been produced in that year by Mr. Geo.Hesselmeyer at Potosi. Two years subsequently the works at Carondelet were put in operation. Three establishments atCarondelet now consume annually about fifteen thousand tons of Missouri zinc ore, the remainder of the production of the mines finding consump- tion outside the State, chiefly at La Salle, Illinois.

Carondelet is advantageously located for the site of zinc produc-

ZINC ORES AND PRODUCTS. 113

ing establishments, both as regards coal and clay; besides, the ore is within easy access, either over the Iron Mountain or the Atlantic and Pacific Railroads. The clays from the vicinity of Cheltenham are of good quality as regards refractory properties, and make distilling ves- sels which have even more than the average durability of similar ves- sels. The character of the Cheltenham clays are indicated by the following analyses of the samples A. and B.; the latter (not complete) was freed from moisture before analysis :

A. B.

Sand and undecomposed silicates 13.972)

I 56.137 Silicic acid 39.157 J

Alumina 30.499 32.515

Ferric oxide 1.481 1.020

Magnesia 1.349 not est.

Lime 1.168 1.603

Alkalis trace. trace.

Water of combination 9.948 10.570

Moisture 1.80« none.

Analysis A, shows the clay to be composed of 79.6 per cent, of plastic or true-clay material, the per centage composition of which is silica, 49.19; alumina, 38.31; water, 12.50. This composition is not widely different from that calculated for pure kaolinite from the symbol Al 2O3 2 Si02, 2H20, requiring, silica, 46.3 ; alumina, 39.8 ; water 13,9.

[The following notes of Dr. Adolph Schmidt (made 1872, but not heretofore used) respecting the coal and clay mines of Parker, Russell <fe Co., Oakhill, near St. Louis, are' inserted in this connection.

Strata below the coal found in a boring on the Russell Mining ground, pit No. 3, in the year 1856 :

1. Blue shale, mixed with clayish nodules of iron ore 3' 8"

2. Limestone colored by iron „ 1' 2"

3. Gray, hard slate , 2'

4. Blue slate 1' 2"

5. Limestone, colored by iron 1' 2"

6. FIRE CLAY 2'

7. Layer of imperfect and impure coal 2"— 6**

8. FIRE CLAY 4' 6"

9. Blue slate 510"

10. Brown slate 1' 4"

11. Blue slate I'lO"

12. Sandstone in layers, shaly, micaceous

13. White sandstone..: 6' 5J"

14. Blue limestone w 6' 8"

GR— 8

114 ZINC ORES AND PRODUCTS.

The section to this point has been found correct and agreeing with the shafts sunk to mine the clay. * * * *

The fire clay is irregularly stratified, wavy formation, and is only found at one single place in the whole property, where it seems to have a mere local development. It is not known between which oi the regular strata the clay lies, because this shaft has been dug through old mining materials. Where the clay was found, no coal was found.

The clay looks gray, owing to an admixture of organic matter, but becomes white on burning. It is the exclusive material for a large manufactory of good fire brick, which the company is work- ing on this ground*.

Analysis of this clay, made by Chauvenet & Blair, of St. Louis:

Hygroscopic water 2.96 per cent.

'Water of composition, and organic matter 7.27 per cent.

Silica.., .' 64.32 per cent.

Alumina 22.82 per cent.

Ferrous oxide 1.75 per cent.

Lime 0.45 per cent.

Magnesia 0.12 per cent.

Soda 0.54 per cent.

Potash 023 percent.

Sulphur 0.12 per cent.

Phosphoric acid 0.00 per cent.

100.58 per cent]

A sample, recently analyzed in this laboratory, showed a less amount of silica and more alumina. The result was, as follows, (mate- rial dried at 102° 0.):

Silicic acid 52.846 per cent.

Alumina 34.214 per cent.

Ferrous oxide 0.665 per cent.

* Keference has been made, in the chapter on lead smelting, to the use of the fire bricks made from the clays of this vicinity, for linings for the reverberatories. The composition of two different specimens have been determined by Mr. James A. Pack and Mr. L. R. Grabill, under my direction. The results are as under :

Laclede. Mitchell

(Pack.) (Grabill.)

Silicic acid 56.307 per cent. 60.394 per cent.

Alumina 35.275 per cent. 35.900 per cent.

Ferrous oxide 0.316 per cent. 1.404 per cent

Ferric oxide 0.088 per cent.

Lime 3.316 per cent. 0.741 per cent.

Magnesia 3.560 per cent. 0.732 per cent.

Potassa > _ Q9_ 0.745 per cent.

Soda } 0.926 per cent. Oi247 per cenK

99.881 100.192

ZINC OKES AND PRODUCTS. 115

Lime 1.001 per cent.

Magnesia 0.763 per cent.

Potassa. 0.084 per cent.

Soda 0.033 percent.

Water and organic matter 10 838 per cent.

100444

This analysis expresses the composition of the clay as a whole, without drawing the distinction between the plastic portion or the true clay and the mechani cally intermixed silicates and sand. It will be noticed from this and the preceding analytical results that the clays are free from injurious amounts of those substances (lime, magnesia, ferric oxide and the alkalis) which impair the refractory properties of the clays. The best Stourbiidge clay gives silica, 63.30; alumina, 23.30; lime, 0.73; ferrous oxide, 1.80; water and organic matters, 10.30 (Percy); the finest china clay, kaolinite, from Cornwall, according to the same authority, has the following composition : Silica 46.29; alumina, 40.09; lime, 0.50; ferrous oxide, 0.27; combined water, 12.67 (sample freed from hygroscopic water before analysis).

For the purposes of the Carondelet zinc establishments, the St. Louis county clays are tempered by mixing with chamotte of old retorts, freed as far as practicable from the residue of previous distil- lations. The usual mixture is two of clay to one of chamotte. The dis- tilling vessels prepared from this mixture are, as before stated, of excellent quality, and, as far as ordinary wear and tear are concerned, will last through at least twenty-eight charges.

The ores are calcined for purposes of removing carbonic acid and water, the calcination being generally effected in kilns. It is impossible for us to reach the average composition of the ores used at the several works without a large series of analyses, especially since the ores are from so many different sources and vary greatly, both in mineralogical composition and grade. Below are given the results of three analyses of samples "of the calcined ores after crush- ing. The results were obtained under my direction by Mr. G. A. Dun- can (I) and John W. Pack (II and III) — the first and second being sam- ples from the Missouri Company's works, and the third from the Mar- tindale works. The results may serve to give some idea of the charac- ter of the material put in treatment, and indicate that I and II were more largely carbonate ore, and that III had a larger amount of cala- mine.

I. II. III.

Silicic acid '. 10.280 10.210 29.447

Zinc oxide 75.240 75.360 70.039

Ferric oxide and Alumina 1.909 2,120 0.527

116 ZINC ORES AND PRODUCTS.

Mansranous oxide .

I. .1 634

II.

1 650

III.

4 340

4430

0 285

, 3 390

3.250

0084

trace

0540

0 280

0289

trace

, 3.090

3520

trace

0 349

100.163

100.829

101.271

Per cent, zinc...,

.. 60.387

60.483

56,213

All the samples contained faint traces of lead and copper oxides ; number III evidently had some blende. The average loss in calcina- tion, estimated by the increase of zinc oxide, must be from 22 to 24 per cent, of the original weight of the raw ore.

The coals used are usually exploited in the Illinois coal fields, which are within convenient access of the furnaces at Carondelet. Forty-five pounds calcined ore, which has been crushed after calcina- tion, are mixed with one-half the volume of coal, and the mixture constitutes a charge for a retort. The yield is about seventy per cent, of the theory, but of the thirty per cent, wastage, a portion is recov- ered by treatment in the upper retorts of the various furnaces of the zinc olust, drippings and skimmings. The ratio of production of these rich products, as nearly as can be ascertained, is about one of dust to three of skimmings and drippings. They show, according to the analysis of Mr. Pack, the following composition :

Zinc 75.899 per cent.

Antimony r 0.372 percent.

Arsenic 0.321 per cent.

Lead and Copper traces.

Iron , 2.052 per cent.

Carbon 1.221 per cent.

Sulphur 0.026 per cent.

Oxygen in combination with metals 11.398 per ^nt.

Sand, etc 9.608 per cent.

100.797

The specimen analyzed was from the Martindale works. The oxygen corresponds to 57.740 per cent, of oxide of zinc.

Another source of loss is in the unvolatilized zinc remaining in the retorts along with the non-volatile matters of the ore and the ashes of the coal. The amount of waste from this source is, of course, exceed- ingly variable. A specimen of old retort with adhering scoria gave 4.152 per cent, zinc, besides 0.1510, lead; copper, a trace; arsenic,

ZINC ORES AND PRODUCTS. 117

0.4348 ; antimony, 0.9488 ; sulphur, 0.8560 ; and iron, 2.2774 per cent. The latter, probably, in part as oxide and belonging to the clay and ashes.

The loss from this and all other sources, is estimated to be about twelve per cent, of the zinc produced.

The Martindale Zinc Works has two blocks of four furnaces each ; in all eight furnaces with 108 retorts each, or 864 retorts.

Carondelet works has 88 retorts to a furnace, and six furnaces. The number of retorts is therefore 528.

The Missouri Company's fumades have 74 retorts each, giving for the four furnaces 296 retorts.

The total production of these furnaces for the year 1875, was 4,650 tons of spelter.

The zinc produced by these works was analyzed in 1874, by Mr. John Pack, under my personal supervision and instruction. His results are appended. No. I being from the Missouri Company's works,

and No. II from the Martindale :

I. II.

Sulphur 0035 .0741

Silica 1346 .1374

Carbon „ .1775 .0000

Iron 7173 .2863

Lead 1001 .0061

Copper 1123 .0018

Arsenic 0603 .0590

Antimony 0249 none

Zinc, by difference 98.6995 99.4347

100.0000 100.0000

MANUFACTURE OF ZINC WHITE IN MISSOURI.

The use of Zinc White, or oxide, as a substitute for white lead, seems to have been suggested in 1845, by Leclerc in France, and for the discovery, the Montaigne medal was awarded him by the French Academy. The earlier methods employed for its production necessi- tated the reduction of the ore to spelter, and the subsequent burning of this zinc metal in a separate vessel, by which it was converted into oxide. In the years 1847 and 1848, English patents, numbers 12,001 and 11,846 were issued to Rochaz* and to Newtonf for improved methods in the manufacture of pigments in the direction of " treating

*Newton's London Journal, Conjoined Series, vol. 43, pages 246 et seq. ^Ibid. pp. 256 et seq.

118 ZINC ORES AND PRODUCTS.

zinc ores and manufacturing of oxide of zinc." The novel features in these improvements consisted in the reduction of the ore and the oxidation of the zinc in an apparatus furnished with a coercitive blast.

The manufacture in this country began at the New Jersey Zinc Works in 1850, and was done by what is known as the direct method, that is, from the ore without the separate or distinct production of the metal, and was the first successful issue, on a practical scale, of .the attempts at this manufacture. The practice then in use, consisted in firing the ore interstratified with fuel in heaps; suddenly cooling with water for facilitating the subsequent crushing in a stamp-mill ; mixing the crushed ore with about forty per cent, of its weight of coal ; charging into a muffle furnace, and collecting the resulting oxide in a suitable apparatus.

This method of manufacture was continued with varying success till sometime in the year 1855, when the process, now used univer- sally in this country, and generally known by the name of its inventor and patentee, Wetherill, was substituted for it. The Washington County Zinc Company, near Hopewell, manufactured oxide under the extension of this patent, using ores produced in this State, and though ndt in operation at the present writing (February, 1876,) the cause of the suspension of the operations is certainly not to be sought for in technical reasons. The works and the mode of production are there- fore entitled to consideration in a report of this character, the more especially since the ores of zinc are so abundant in the State, and the product has intrinsic value as a legitimate substitute for white lead in certain applications.

The furnace used is a low-arched chamber, the sole or bottom of which is formed of wide grate bars, placed contiguously, and provided with numerous conical perforations. Below these bars is an air cham- ber which is supplied with a low pressure blast, from a centrifugal blower. The arch of the upper chamber has two openings, one con- necting with the stack and the other connecting by means of an iron pipe with the apparatus for condensation of the oxide. Both of these openings are so arranged as to be closed at will, and as the stages of the operations require. Through the shell and on each side of the furnace, and at the level of the grate bars are several openings or work doors, which give access to the upper chamber for the purpose of charging and discharging and of manipulating the charge. These openings are closed, when necessary, by banking up ashes or loam around them.

The furnace is operated by first spreading a layer of bedding coal over the grate bars and igniting the same,' the combustion being aided

ZINC ORES AND PRODUCTS. 119

by the blast from the air chamber beneath. Upon this is spread a layer of crushed ore intimately mixed with fine coal or dust for reducing purposes. As soon as this layer becomes sufficiently heated to 'effect the reduction of the oxide of zinc — indicated by the peculiar blueish-green flame of burning zinc appearing — the flue connecting with the stack which has been opened is closed, and that leading to the condensing apparatus is opened, at the same time the work doors are closed up by banking the ashes around the openings. The process is aided by frequent rabblmgs or stirrings, and is terminated when the zinc flame is no longer to be seen — usually after the lapse of from four to six hours. The scoriaceous mass or residuum is now with- drawn, a fresh layer of bedding coal is introduced and ignited either by the sufficient heat of the grate bars, or by some of the residue which is, for that purpose, allowed to remain on the sole of the fur- nace, and the operations repeated as above.

The furnaces are usually built in blocks ; a flue of brick connects them with a sheet iron pipe four feet in diameter, which opens into a brick chamber or tower, where the oxide meets with water to aid in condensation and thence passes into bags of strong cotton fabric, where the oxide is collected, and the gaseous products of the furnace filter through the pores of the bags into the exterior atmosphere. The draft of the furnace is aided by an exhaust fan placed intermedi- ate to the furnace and the bags.

The method of collection in bags was early introduced at the New Jersey works, and has been found to be the only effective means. It is capable of extension for the collection of other valuable metal- lurgical products, such as fume, and has hardly received the attention that its simplicity and thoroughness warrant.*

The rationale of the operation is not difficult to understand. The reduction of the oxide of the zinc ore is effected by carbonic oxide, the products of the action being carbonic acid and metallic zinc, the latter in the state of vapor. At a temperature somewhat less than that necessary for the reduction, which condition would be found in the upper part of the charge, the vapor of zinc will burn in an atmos- phere of carbonic acid, producing carbonic oxide and zinc oxide. The reduction of the ore and the combustion of the zinc vapor there- from go on almost pari passu, observations showing that almost all the oxidation is effected previously to the zinc leaving the charge and not in the space of the chamber above the charge. When this latter does take place there is produced and collected in the flues, a larger amount of so-called blue-powder, a mixture of finely divided metallic

*0n this point see the author on Loss by Volatilization, Jour. Franklin Institute, Feb., 1871.

120 ZINC ORES AND PRODUCTS.

zinc and oxide. The formation of this blue powder was a serious objection to the successful practical working of the muffle-furnace ; when, however, the furnace now in use is charged properly the pro- duction of this substance is reduced to a minimum.

Blende-bearing ores should be roasted before treatment. Gener- ally, such roasting is done in a reverberatory with a double sole. If galenite is present in the ores it is largely carried over by the specifi- cally light oxide of zinc, and appears in the product chiefly as lead oxide or lead sulphate. At the Keystone Zinc Works, near Tyrone,. Pennsylvania, galeniferous zinc ores, containing from six to twelve per cent, lead, were treated by this process, and the so-called Bartlett white lead was made in a similar manner by burning the mixture of galena and blende from the buddies of the Silver Hill mine, Davidson* county, South Carolina. The annexed analyses of these products by the author* are introduced for illustrating the volatility of lead under the circumstances discussed:

Keystone Oxide. "Bartlett White Lead.'*

Zinc oxide 73.246 72.083

Lead oxide 0.274

Antimony oxide trace.

Ferric oxide trace.

Lead sulphate 25.084 23.968

Zinc sulphate 0.574 0.810

Zinc chloride 0.839

Ferric chloride 0.071

Antimony chloride trace.

Cadmium chloride 0.256

Cadium sulphate 0.186

Calcic carbonate 0.729

A process for converting lead ores into a paint material suscepti- ble of taking the place of white lead, by a method similar to that described above has recently been patented. f The product is unex- ceptionable in color, and mixes readily with oil. Some recent analyses by the writer show the following to be the compositions of two sam- ples prepared by this method of burning, with slight differences, how- ever, in the modes of collection, "A" being condensed without, and

"B" by use of water:

A. B.

Zinc sulphate 0.4112 0.3488-

Ferric sulphate trace

* Watt's Dictionary of Chemistry, II supplement, page 725, from Chemical News, XXIII, 236.

f Now in use at Lone Elm, Joplin, in connection with the hearths, for the con- densation of fume.

ZINC ORES AND PRODUCTS. 121

A. B.

Lime sulphate 0.0151 0.0045

Lead sulphate 38.9874 39.5008

Lead carbonate 2.9822 17.9145

Lead oxide 533813 37.3707

Zinc oxide , 4.2938 4.6441

Ferric oxide 00551 0.1104

Sand.... 0.0091 0.0221

Organic matter, chiefly fibre from bag 0.0045 0.0024

100.1397 "99^9183

The quantity of residue left on the grate bars after proper burning of the zinc ore by the Wetherill process is about equal in weight to the weight of the ore introduced. It is ascoriaceous mixture of the foreign matters ot the ore, ashes of coal, unconsumed coal, and some oxide of zinc. Its quality in respect to the amount of this latter has been found to range between 2.5 per cent, and 22 per cent, being always smaller when the charges are of small depth, and greater as the charges are increased in thickness. The thickness of the charge spread over the bedding coal is usually from four to six inches, at both the Lehigh, (Pennsylvania,) and the New Jersey, (Newark,) works, and the amount of oxide in the residue under such conditions of charging and working never exceeds four per cent. Any notable increase in thick- ness is accompanied by increased wastage of oxide in the residue,, irrespective of the time that may be given, after certain limits, to the elaboration of the charge, so that economy in both time and zinc is secured by thin charges. Hence the necessity of crushed ore and dust coal for the charge, and of small coal (usually chestnut size) for the bedding fuel*

The greater energy of blast which would be required for thicker

charges might also cause a greater calorific intensity resulting, in

interference with the proper reactions, and possibly causing, also, a

slagging or semi-fusion of the charge, interfering with the disen-

•gagements of zinc vapor.

The effect of adding to the depth of charge in the Wetherill fur- nace, is illustrated in the annexed table * of results of analyses of

* Condensed from testimony and argument in Wetherill vs. the N. J. Zinc Co^ Philadelphia, 1871.

122

ZINC ORES AND PRODUCTS.

the residues of certain experimental charges in the New Jersey fur- naces :

THICKNESS OF CHARGE.

TIME OP WORK- ING.

PER CENT. OF OXIDE IN RESIDUE.

ANALYST.

'6 to 8 inches

5 hours..

2 03 per cent

T. C. Garrett.

G to 8 inches

6 hours

1.20 per cent ....

Author.

6 to 8 inches

6 hours

3-203 per cent

Author.

J9.75 per cent

Charles Roepper.

7 J inches

14 hours

10.54 per cent

Author.

( 8 06 per cent

T. C. Garrett.

No measure

5> hours

6 49 per cent

Charles Roepper.

No measure

11 hours .

6 57 per cent

Charles Roepper.

14 inches

8 hours

7 95 per cent

Charles Roepper.

14 to 17 inches

13J hours

Charles Roepper.

16 to 19 inches

28 hours

13 05 per cent ....

Charles Roepper.

16 to 19 inches

28 hours

10 45 per cent

Author.

16 to 19 inches

10 23 per cent

Author.

The New Jersey Company works ore of high grade containing a large proportion of willemite, zincite and the zinciferous iron ore, "Franklinite. The last named species is rich also in manganese, so that the residue is notably both iron and manganese bearing, and is used for mixing with iron ores for treatment in the blast furnace for the manufacture of an excellent quality of spiegeleisen. Experience has shown that where the residues contain more than four per cent, oxide of zinc they are not adapted to blast furnace treatment, and their introduction results in serious and expensive disadvantage to the charge in the furnace, so that the profitable utilization of this valuable matter depends on the close working of the oxide furnaces. The Lehigh Company works under the double disadvantage of start- ing with lower grade ores, and of producing a residue which cannot' be utilized, and is therefore forced to clean up the charge as closely as is practicable. The Missouri Company has not run its residue xlown as cleanly as that of either of the above named establishments, probably on the grounds of starting with rich ores and of economy in fuel, but whether the practice has, in reality, been subservient to increase of profit is a point still open to demonstration.

The Hopewell furnaces are eight in number, built in one block, each with a hearth of 4.5 feet by 6 feet, and with a height of 27 inches from the grate bars to the centre of the arch. The bedding coal for

ZINC ORES AND PRODUCTS. 123

a charge is about 250 pounds weight of Pennsylvania anthracite spread evenly over the grate surface and giving therefore a thickness of one and a half inches. The charge proper consists of 400 pounds ore and 200 pounds of small coal and dust thoroughly mixed before introduc- tion. The coal is mixed Pennsylvania anthracite and that from Spadra, Arkansas. The ore comes chiefly from the Washington county lead mines, and contained occasionally a small amount of galenite. Sometimes Dade county smithsonite was employed. A representa- tive lot of specimens gave the following result on analysis :

Zinc oxide 53.997 per cent.

Ferric oxide 4.263 per cent.

Alumina 0.632 per cent.

Ferrous oxide 1.039 per cent.

Lime 2393 per cent.

Magnesia 1.546 percent.

Lead oxide trace.

Cupric oxide , 0.052 per cent

Cadmium oxide 0.173 per cent.

Antimony oxide 0.170 per cent.

Carbonic acid 24.302 per cent.

Silica „ 8.510 per cent.

Water 2.414 per cent.

Sulphur 0.242 per cent.

99.633

It is evident from this result that the ore is a mixture of about two-thirds smithsonite and one-third calamine, containing, however, a fractional per centage of blende and foreign sulphides.

The charge indicated required nearly six hours for its elaboration. The ore yielded a little more than thirty per cent, of oxide, leaving therefore as stated above, a large part of the zinc in the residue. This is confirmed by the annexed result of analysis of the residue:

Zinc oxide 25.426 per cent.

Ferrous oxide 12.528 per cent.

Alumina 4.247 per cent.

Lime 5.311 percent.

Magnesia 1.692 per cent.

Ferrous sulphide 8.723 per cent.

Cuprous sulphide 0.175 per cent.

Silica 3 1.740 per cent.

Carbonaceous matters 10.040 per cent-

99.882 per cent.

The quality of the oxide varies widely according to the foreign matters in the ore, being influenced to the greatest degree by the lead and the sulphur. Several brands of the oxide have been produced

124 ZINC ORES AND PRODUCTS.

the character of each being indicated by the analytical results given

below :

I. II. III. IV.

Zinc sulphate U53 0.203 1.001 0.824

Calcic sulphate 0.008 0.041 0.080 0.011

Lead sulphate 4.970 3.243 1.271 0.249

Lead oxide 1.047 4.598 0.399 0.814

Copper oxide .'.. 0.063 0.186 0.043 0,021

Ferric oxide trace trace trace trace

Zinc oxide, by difference 92.749 91.729 97.206 98.081

I is "Star No. 1;" II, " Star No. 2;" III, "Star No. 3;" IV > " Oxide."

Two samples produced entirely from Dade county ores, were analyzed under my directions by Mr. P. E. Blow, and the results were published in the Keport of the Curators of the State University for the year ending June, 1875. These results are reproduced below :

V. VI.

Zinc sulphate 0.3001 0.4998 per cent..

Calcic sulphate 0.1114 0.1400 per cent.

Cadmium sulphate 0 2024 per cent.

Zinc chloride 0.0948 traces

Cadmium chloride 0.9446 traces

Lead sulphate 0.0195 0.0042 percent.

Lead oxide 0.4995 1.1488 per cent.

Ferric oxide 0.0322 0.0976 per cent.

Zinc oxide, by difference 97.9979 97.9062 per cent.

100.0000 100.0000 per cent*

V was of good color and body ; VI was somewhat " off color,'* having a decided buff tint and marked impure. The ore from which they were produced contained 0.842 per cent, cadmium oxide.

While the works were in operation, they consumed annually three thousand tons of ore aid twenty- seven hundred tons of coal for all purposes. The product was from eight hundred to a thousand tons of oxide of the various grades.

The chief use of zinc oxide or white is as a basis for a pigment. It is rather more expensive than white lead, but is claimed by some to have even better covering properties in the ratio of 13 to 10; Further, it is not so apt to change color, retaining its pure white tint much longer than the best white lead, and is not blackened when exposed to emanations containing sulphurretted hydrogen. A further and more limited use of the oxide is in the conversion of caoutchouc into the material known as ebonite.

The shipments of oxide from Hopewell, by the Washington County Zinc Company, amounted in 1875, to 2,446 barrels, weighing 489,000 pounds, of the several grades. The value of the shipments is given at 144,010.

THE IRON INDUSTRY,

WITH ESPECIAL EEFERENCE TO THE MANUFACTURE OF

CHARCOAL IRON.

Uj

l_

IRON INDUSTRY OF MISSOURI.

MAKAMEC FURNACE.

The Maramec furnace (T. 37, R. 6 W., Sees. 1 and 2), owned by the heirs of Thomas James, and operated under the management of William James, Esq., of St. James, is the oldest establishment now in operation in the State. Smelting work was begun at the location as early as 1824.

The present furnace is of thimble top style, its dimensions being given in the accompanying section (Plate I.) It has two tuyeres of three and three-quarter inches diameter, delivering blast of three pounds pressure. The blowing apparatus is worked by water-power, fur- nished by the ample spring at the works. The diameter of the blower is 4 ft. ; stroke 4 ft. 6 in.; two cylinders ; number of revolutions per minute, 16. The calculated capacity of the apparatus is 3,612 cubic feet of air per minute ; or, with an average daily production of four- teen tons iron, one ton of iron requires 13.86 tons of air.

The ore is furnished by the Maramec bank, near the furnace. [For description of this deposit by Schmidt, see report of 1872, pp. 144, et seq. I ]. A carefully selected sample gave the following result :

Ferric oxide 73.365 per cent.

Ferrous oxide , 2.237 per cent.

Alumina 7.534 per cent.

Magnesia , M 2.044 per cent.

Lime trace.

Silica 14.740 per cent.

Phosphoric acids trace.

Sulphur 0.057

t

99.997 Metallic Iron 53.094 percent.

The yield shown by the above analysis is about an average of that produced by working. During the three months of December, (1874), and January and March, (of 1875), there were required 4,472, 4,345

128 . THE CHARCOAL IRON INDUSTRY.

and 3,926 pounds of ore, respectively, to produce one ton (2,240 pounds) of iron, corresponding to 50.6, 51.6 and 57 per cent, yield for the ore, or a mean of 53 per cent.

flux : The limestone used for flux is nearly a true dolomite, as is shown by the annexed result of analysis :

Calcic carbonate 52.611 per cent.

Magnesic carbonate 42.415 per cent.

Ferric oxide and alumina 1.330 per cent.

Insoluble matters 4.201 per cent.

100.557

A special examination showed it to contain 0.036 per cent, of sul- phur and 0.005 of phosphoric acid (=0022 of phosphorus.)

The usual charge consists of 520 pounds ore and 100 pounds flux, one hundred such charges being introduced daily. In January, 1875, 1,578,280 pounds ore were run through in 2,772 charges, and in March of the same year, 2,006,410 pounds of ore were used in 3, 562 charges, or at the rate of 569 pounds of charge for the first and 563 pounds for the second.

Fuel consumption : The records of the furnace show a consump- tion of 153 bushels of charcoal per ton of pig iron produced. The charcoal contains, 8.66 per cent, ash ; 497 hygroscopic water, and 86.37 carbon. Estimating the weight per bushel to be at the rate of eighteen pounds, 1.221 tons charcoal are required per ton of pig iron, ;or 1.053 ton of pure carbon to the ton of iron.

Products : The average daily production of iron is about fifteen tons. Taking the month of April, 1875, to represent the character of the product, it will be found that the relative amounts of the three grades of iron are as (No. 3), 10 to 10.5, (No. 1) to 44 (No. 2). The chemical composition of these several grades are found to be as be- low; *

I. n. III.

Carbon, graphitic 2.024 2000 2.662

Carbon, combined 2.276 0.887 0.288

Silicon 1.378 1.246 1.337

Phosphorus trace trace trace

Sulphur 0.048 0.136 0.091

Manganese 0.904 0.717 0.852

Iron, by difference 94.370 95.010 94.770

100.000 100.000 100.000

* For methods of Analyses followed, see Fresenius Quantitative Analysis, Fourth English Edition, pp. 658, et seq.

THE CHARCOAL IRON INDUSTRY. 129

From the data given above in connection with the analyses of the raw materials used, the amount of -slag produced to the ton of iron will be found to be 0.858 ton. Of this quantity the ore contributes, 0.569 ton; the flax, 0.183 ton, and the charcoal 0.106 ton. The compo- sition of the slag is indicated in the annexed analysis in which the sulphur is regarded as combined with a part of the calcium into cal- cium sulphide.

Composition Maramec Slag.

Silica 64.746 per cent.

Alumina 7.729 per cent.

Ferrous oxide 2.282 per cent.

Lime 16.973 per cent.

Magnesia 5.349 per cent.

Soda 1.812 percent.

Potassa 0,702 per cent.

Phosphoric acid 0.572 per cent.

Calcium sulphide 0.134 percent.

100.299

Sulphur in slag 0.059 per cent.

Phosphorus in slag 0.249 per cent.

The percentage of oxygen of the silica is 34.53, and that of the bases, 11.68, giving a ratio of 1 to 3 (nearly) and constituting, there- fore, an acid silicate.

Combining the results of the operation of the furnace with further details furnished by the chemical investigations, the distribution of the raw materials — solid and gaseous — entering into the production of one" ton of average pig iron at the Maramec furnace, may be ascer- tained with sufficient accuracy to form the basis for calculations con- cerning the calorific effect of the fuel. The raw materials are ore, flux, charcoal and air, and the products are pig iron, slag and the gases escaping from the tunnel-head. Tabulated, the relations of these fac- tors and products will stand as follows, the calculations being made

to the ton of iron produced :

Iron. Slag. Gases.

ORE, 1.966 tons, containing :

("Iron 0960

Ferric oxide 1.371 -^

(Oxygen 0.415

{Ferrous oxide.. 0.048

Oxygen 0.006

f Silicon '. 0.010

Silica 0.500<| Oxygen 0.010

(.Silica 0.480

Lime and magnesia 0.041

GR— 9

130 THE CHARCOAL IRON INDUSTRY.

FLUX, 0.339 tons containing :

Silica : 0.014

Lime 0.100

Magnesia « 0.069

Carbonic acid 0.154

CHARCOAL, 1.221 tons containing :

Carbon 0,030 1.024

Water 0.001

Ashes O.lOti

AIR, 13.867 tons containing :

Oxygen 3.200

Nitrogen 10.590

Moisture* 0.077

If in this blast furnace the total carbon of the charcoal was burned to its maximum of oxidation, that is, to carbonic acid, the amount of heat developed would be 8,484 ton units of heat, or in other words, its calorific power would be enough to raise the temperature of 8,484 tons of water from 0° to 1° centigrade. But such calorific power cannot be realized in blast furnace practice, for the gases escaping from the tunnel head of any furnace are mixtures of carbonic acid and carbonic oxide, and indicate, therefore, a more or less perfect combustion, so far as the heat production is concerned, according to the preponder- ance of the one or the other. Hence, the ratio of these two escaping gases when determined, gives an index to the working of the furnace,, considered in respect to its fuel consumption. This ratio of CO (car- bonic oxide) to C02 (carbonic acid), Grunerf fixes as 1 to 1.2L7 in an ideally perfect working coke furnace ; it is always less in charcoal furnaces, for reasons noted hereafter, and in the great furnaces of the Cleveland ore district, when in good condition, it is generally between 0.5 and 0.7, and for bad working 0.35 to 0.40.

If the final product were carbonic oxide alone, the number of heat units produced by an unit of carbon would be 2,473, so that the calo- rific power produced in the furnace must stand somewhere between this number and 8,080 — the number produced by the complete com- bustion of carbon into carbonic acid — and will vary accordingly as there is more or less of the one or of the other of these two compounds of carbon and oxygen produced. The reason that neither the maxi- mum nor the minimum amount of heat is not obtained will be obvious

* Moisture, estimated at 75 per cent, of saturation, and saturated air contains 0.75- of water.

t Blast Furnace Studies, p. 15. Translation.

THE CHARCOAL IRON INDUSTRY. 131

from an examination of the reactions necessary in the furnace to pro- duce the iron.

"In every furnace of this type," says Gruner,* there are two con- trary currents in motion, and reacting the one upon the other — a gaseous current ascending, the temperature of which is at first very high, and decreases very gradually till it quits the furnace at the tunnel head or top ; and a solid descending current composed of the ores, the fluxes and the fuel, the temperature of which goes on in- creasing always under the action of the gaseous current in the oppo- site direction. Of these two currents, the one is slow, the other very rapid. The solid materials of the charges rarely descend with a greater speed than 20 inches per hour, whilst the gases pass upwards with a velocity of 20 inches per second. * * * The air blown into the furnace at the tuyeres is almost instantly transformed into carbonic oxide,f and this gas, in its passage up the body of the furnace, acts more or less directly in reducing ores — that is to say with or without the aid of solid carbon. The reduction of the oxide of iron may take place in three ways :

1. 3 CO + Fe2 O3 = 3 C02 + 2 Fe.

2. 3 C + 2 Fe2 O3 = 3 CO2 + 4 Fe.

3. 30+ Fe2 03 = 3 CO + 2 Fe.

It may at once be remarked that the first two ways of reduction are not in fact realizable, if we adopt the proportions giyen in the formulas. In these conditions the metallic iron would be partially reoxidized by the carbonic acid. We know by the experiments of M. Debray, confirmed by Mr. Lowthian Bell, that in presence of equal volumes of carbonic oxide (CO) and carbonic acid (C02) peroxide of iron (Fe2 O3) and metallic iron (Fe) are both brought to the state of protoxide (Fe O). But these two first modes of reduction are impos- sible taken singly ; they generally help, with the third mode, in pro- ducing the final result, and in fact, the gases taken at the furnace top are always composed of a mixture of CO and C02. According as the one or the other mode of reduction has the greater share in the final

* 76. pp. et seq.

f I may add here that the excellent authority of Tunner is against the assumption that carbonic oxide alone is present in the lower part of the furnace, or that, in fact there is any part of the furnace which does not contain both carbonic acid and carbonic oxide in varying proportions, dependent on various conditions. Consult in this con- nection Prime's translation of Akerman's Researches on the Consumption oj Heat in the Blast-furnace Process. Transactions Am. Inst. Mining Engineers, Vol. I, pp. 426, et. seq.

132 THE CHARCOAL IRON INDUSTRY.

result, the proportion of CO or CO2 in the gases taken at the furnace top is the greater. But it is very easy to show that these three modes of reduction require very different quantities of caloric; and in this point of view — that is, in reference to the consumption of fuel — it is not a matter of indifference which of these reactions takes place in blast furnaces*"

The calorific effect of each of these reactions is made up of the amount of heat absorbed and the amount given off. The first is con- stant for all those reactions, being exactly the amount of heat which an unit of oxygen would produce in burning iron to Fe2O3, but work- ing in the opposite direction that is being absorbed by reduction instead of liberated by oxidation. It has never been determined rigorously, but is generally estimated to be about 4,500 heat units. The second, that is the amount of heat given off, is variable, being for the first reaction 4,205 units, for the second 3,030 units, and for the third 1,855 units for each unit of oxygen removed by the carbonic oxide or the carbon. Comparing these variables with the constant, it will be seen that in the first reaction the heat liberated by the com- bustion of the carbonic oxide into carbonic acid by the oxygen of the Fe2O3 is almost equal to that absorbed by the reduction of the Fe203 to 2 Fe, while in the other reactions in which the reduction is effected by st)lid carbon, (in the one case oxidized by the change to C02, and in the other, to CO), the heat absorbed is greater by about 1,500 and 2,600 units, respectively. In other words, to effect a reduction by solid carbon, the amount of the latter must be increased over the amount required in the form of carbonic oxide, and the amount of increase is relatively greater as carbonic oxide or carbonic acid is the final pro- duct. Representing the amount of carbon required to effect the reduc- tion by carbonic oxide by unity, the solid carbon burned to carbonic acid (reaction 2) becomes 1.55, and to be burned to carbonic oxide, (reaction 3), it must be increased to 2.33.

The ideally perfect furnace considers the reduction by carbonic oxide only, and regards the final products as carbonic oxide and car- bonic acid in the proportion of one weight of the first to 1.217 of the latter. For one unit of pig iron produced there will be consumed 0.880 of carbon, producing 1.408 of carbonic acid and 1.157 of carbonic oxide. If the relation between the two forms of oxidation of the carbon in the gases escaping from the tunnel head be the index of the effectiveness of the fuel in the furnace, analysis of these gases will give the required knowledge with all necessary exactness. But the performance of this analytical work is certainly not easy, nor is its execution at iron establishments generally provided for. In by far

THE CHARCOAL IRON INDUSTRY. 133

the larger number of cases the determination of the ratio of the furnaces, gases can only be arrived at by calculations, which being based on so many assumed positions, necessarily lead only to approxi- mations, interesting in a theoretical view, but without the element of certainty to give them any great practical significance. Nevertheless, these calculations are at present the only guide that we have to knowledge of how far the furnaces in this State are proportioned and governed in order to secure economy in the consumption of fuel.

The distribution of materials given on a preceding page, in con- nection with certain data, established by Bell, Akermann, Gruner and others, enable us to reach the following approximation to the amount of ton-units of heat necessary and required to produce one ton of iron in the Maramec furnace :

Bed uction of iron from oxide [0.960 ton X 1780 units a] 1,708 ton H-U

Carbon impregnation [ .030 X2467 b] 74 "

Expulsion of carbonic acid from limestone/.... [0.339 X 370 c] 125 "

Decomposition of carbonic acid from limestone [0.154 X3200d] 493 " Decomposition of water from blast and

charcoal [0.015 X29638e] 444

Eeduction of silicon from silica [0.010 X7830 f] 78

Fusion of pig iron [1.000 X 330g] 330 "

Fusion of slag [0.858 X 550h] 472 "

Heat transmitted through furnace walls k 113 "

Heat carried off in the tuyere water 1 14 "

Heat carried off by gases from tunnel head m ;.. 553 "

Total units of heat per ton of iron 4,404 "

To produce this amount of heat there were consumed 1.052 tons of carbon, burning in such a manner 31 per cent, should form carbonic acid and 69 per cent, should be converted into carbonic oxide, and

CO the resulting gases will be Q7T==0.712; while the calorific power,

represented by the heat consumption, will be 76 per cent, of that possible for the same amount of carbon if burned as in the ideal furnace. It may be well to mention in this connection, that the activity of furnaces varies greatly with the character of the fuel and the ore. Reference will be made to some of the peculiarities of charcoal furnaces in comparison with those using coke in treating of some of the hot blast charcoal furnaces of this State.

a— Bell's number; b— Bell; c— Bell; d— Bell ; e — Akermann; 34,462 is the usual number given for calorific power of hydrogen, but this factor includes the deduction for heat absorbed in converting 9 units of water (formed from one unite of hydrogen) into steam [34,462— (9x536)=29,63S ; f— Akermann ; g— Bell ; h— Bell ; k— Akermann ; 1— Akermann ; m — Akermann.

134

THE CHARCOAL IRON INDUSTRY.

Bloomery at the Maramec Works : The bloomery has eight fires, each running eight charges per day, of from 12 to 14 hours ; one three- ton trip-hammer serves all the fires. The tuyere enters the fire about 1-J- inches; its diameter is 1| inches; the bottom plates are not cooled, but rest on the ground, and last from one to three months.

A charge is 280 pounds of pig iron, 2-5 being white or mottled iron and 3-5 gray iron. A charge gives a loop of 246 pounds, which is hammered into two blooms (120 Ibs. each) at each heat, without any reheating. Eighty bushels of charcoal are required per ton (2,464 pounds) of bloom produced. Each fire requires two hands, and makes only one turn per day.

The power for the blowing engine is furnished by the spring. There are two vertical cylinders, 6 feet 2 inches in diameter; length of stroke, 4^ feet; number of revolutions, 14 per minute.

The total production averages one hundred tons of blooms per month, in winter time, and somewhat less in summer.

OZARK FURNACE. [Ssc. 21, T. 37, R. 9 ; PHELPS COUNTY.]

This furnace was built in 1S74, but owing to the depression of the iron industry throughout the country, was blown out in the spring of 1875.* (For form and dimensions sse plate 2.) While running it used a mixture of equal weights of ores from the Beaver, f (S. -J Sec. 33, T. 37, R. 8 W., Phelps county), the Hancock, (Sec. 14, T. 38, R. 12 W., Miller county), and the St. James banks. The composition of these ores is indicated by the annexed results of analyses by Mr. Hare :

Beaver Ore. St. James Ore. Hancock Ore.

3.800

Manganous oxide ,

.Lime

0.384

0.221

Silica

3.853

Phosphoric acid

0.156

Sulphur

0151

Water ...

Metallic iron. Phosphorus ;

100.352

64128 0.0671

73.604

79.437

2.608

5.229

0.081

12.402

0.174

4.803

0.290

6.491

11.941

0.230

0.074

0.214

0.073

not est.

100.177

97.298

51.523

55.606

0.1004

0.0323

* The Ozark furnace resumed work during May, 1877. f For description (Schmidt) see report, 1872, 148.

THE CHARCOAL IRON INDUSTRY. 135

According to estimates made at the time the furnace was in blast, 1,502 tons of ore made one ton of iron. To this were added 0.175 tons of magnesian limestone for flux, (= 12 per cent, of the weight of the ore) which contained the following constituents, centessimally expressed :

Calcic carbonate 55.541

Magnesic carbonate 41.168

Ferric oxide and alumina 0.734

Insoluble matters 3.795

Ferrous di-sulphide '. 0.091

99.329

Special examination for phosphoric acid, showed 0.004 per cent. (= 0.0017 phosphorus.) The sulphur is 0.0485 per cent.

The charcoal was used in the proportion of 0.762 tons per ton of iron made. The blast was heated to the temperature of melting lead (325°0.) and entered the furnace by'two tuyeres.

The iron contained :

Carbon 2.6588 per cent.

Silicon 0.4199 per cent.

Manganese 0.5713 per cent.

Phosphorus..... 0.0066 per cent.

Sulphur i 0.0440 per cent.

Iron, by difference 96.2994 per cent.

100. 0000 per cent.

The distribution of the materials show that the slag forming sub- stances amounted to 0.528 ton per ton of Iron. The mean of two analy- ses gives the following composition to the slag :

Ozark Slag.

Silica « 48.928

Alumina 16.617

Ferrous oxide 2.573

Lime 27.895

Magnesia 0.855

Potassaand soda 2.202

Calcium sulphide 0.456

Phosphoric acid 0.078

99.625

Sulphur 0.2005

Phosphorus .00340

The oxygen ratio of silica to the bases is about 1-J to 1 (more exactly 26 to 17), showing the slag to consist of a bi-silicate in mix- ture with a singulo-silicate.

136 THE CHARCOAL IRON INDUSTRY.

The difficulties attendant upon bringing the opening work of a furnace into a fair or satisfactory condition had hardly been over- come in the instance of the Ozark furnace before it was put out of blast. No statement of its working effect could therefore be just, and comparisons based upon the fuel consumption and produce of iron would result only in erroneous conclusions. The furnace is owned by the Ozark Iron Company, and was built and operated under the general management of William James, Esq., of St. James. The character of the work upon the furnace and upon the other improve- ments of the estate is most substantial.

SCOTIA IEON WORKS.

(N. E, J, SEC. 1, T. 38, R 3 W., CRAWFORD COUNTY.)

The furnace is located eight miles southeast from Leasburg, its station and depot on the Atlantic & Pacific Railroad. It was erected in 1849, and has made a most creditable record in respect to its pro- duction and the quality of its iron.

It is of the open top form with two tuyeres (4 inches in diameter), the blast having a pressure of from two and a half to three pounds, and a temperature of from 500° to 600° Fah. (say 325° Cent., or about the melting point of lead). The hearth is of fine sandstone quarried near Leasburg, standing a campaign of about six months duration.

The blast is furnished by a steam blowing-engine with a steam cylinder of twenty-nine inches diameter. The blast cylinders are two in number, each four feet diameter, and with six feet stroke. Eighteen to twenty revolutions are made per minute. The daily work is therefore 4,127,000 cubic feet of air. The blast is heated by passing thirty syphon pipes, in two rows of fifteen each, entering by- eight pipes and returning by seven.

The ores are calcined in heaps of fifteen feet height, and twenty by sixty feet base, holding about one thousand tons. The heaps burn three weeks. A sample each of raw and roasted ores gave as follows (each mean of two analyses):

Raw Ore. Calcined.

Ferric oxide 93.051 83.305

Ferrous oxide 1.262 10.513

Alumina 0.545 0.557

,Manganous oxide 0.262 0.235

Lime trace trace.

Magnesia 0.018 0.974

Silica 5.361 5.082

Sulphur 0.046 0.031

Phosphoric acid 0.075 0.174

100.415 -100.871

THE CHARCOAL IRON INDUSTRY. 137

The metallic iron in the samples analyzed is 66.61 per cent, for the raw, and 66.491 for the calcined, and the amounts of phosphorus are 0.0327 and 0.0759 respectively.

["The ore frequently melts in the interior of heaps and runs or drops down, forming beautiful stalactites, often with a velvet-like- crystalline, dark surface." Schmidt's notes, 1872.]

Flux: The limestone used in the furnace, is from the third mag- nesian formation, and is quarried on a level with the tunnel head, a few yards back of the furnace. It is less magnesian or dolomitic than other belts of the same formation examined, and contains:

Calcic carbonate 84.078 per cent.

Magnesic carbonate 12.654 per cent.

Ferric oxide 0.423 per cent-

Alumina 0.564 per cent.

Insoluble matters 2.565 per cent.

100.284

Besides 0.046 per cent, of sulphur, possibly as pyrites, and a faint trace of phosphoric acid. To every 850 pounds of ore in a charge, 8ft pounds of limestone are added, the flux being upwards of nine per cent, of the ore.

Fuel: The wood for charring cuts at an average rate of twenty- five cords from the acre; the cost of chopping is sixty cents per cord, the latter yielding in the heaps from thirty-five to forty bushels of charcoal. Five cents per bushel is paid for charring, deducting, how- ever, the cost of cutting the wood. A heap contains from forty to fifty cords; burns from eight to ten days, and cools five or six days.

The wood is mostly oak and hickory ; the charcoal has four per cent, ash and about the same amount of hygroscopic water. Twenty bushels (say, 360 pounds*) are added with a charge, or, with an aver- age daily production of 20.2 tons of pig, the consumption of coal is 0.9115 tons per ton of iron made.

Products: The four qualities of pig made are No. 1 (73 per cent, of the total production), No. 2 (16 per cent.), No. 3 (8 per cent.), and No. 1 (3 per cent). Most of the iron is used in St. Louis ; the No. 2" is sold for car- wheel foundry purposes, and the white is utilized at the bloomeries of South St. Louis. The general grades show the fol- lowing amounts of foreign matters :

I. Mottled. 3 White.

Silicon 0.8260 0.541 0.768 1.180

Manganese 0.2419 ' 0.374 0.273 0.26G

Sulphur 0.0256 0.043 0.047

Phosphorus trace. trace. trace. trace.

*The coal at the Scotia property weighs more than eighteen pounds per bushel, as there is less admixture of poplar woods used ; the weight is still used in this for sake of uniformity.

138 THE CHARCOAL IRON INDUSTRY.

In making one ton of pig 0.716 ton of slag is produced, the con- stituents of which, according to our analyses, are :

Silica .'. 51.676 per cent.

Alumina 6.437 per cent.

Ferrous oxide 0.871 percent.

Lime 22,065 per cent.

Magnesia 16.399 per cent.

Soda 1.003 per cent.

Potassa 0.652 per cent.

Calcium sulphide 0.159 per cent.

Phosphoric acid 0.311 per cent.

Phosphorus , .. 0 136

Sulphur .. 0.076

The oxygen of the bases is 16.44; that of the silica is 27.56, giving ratio of 1:1.7 nearly, and showing as a mixture of bi- and singulo-sili- cates.

The foregoing figures give the following distribution of the raw material for the production of one ton of pig, in the Scotia furnace :

'Ore 1,855 tons, containing Iron. Slag. Gas.

Iron 0.954

Oxygen 0.309

Ferrous oxide 0590

Oxygen 0.007

Silicon 0.011

Oxygen .011

Silica, alumina, magnesia, etc 0349

.Flux, 0.175 tons, containing:

Silica 0.005

Lime 0.083

Magnesia 0.011

Carbonic acid 0.076

Charcoal. 0.9115 tons, containing :

Carbon 0.035 0.753

Ash 0.036

Moisture 0.045

Air, 7.604 tons, containing :

Oxygen 1.750

Nitrogen 5.811

Moisture 0.043

By using the same factors employed for the calculation of the Maramec, with the new variables given in the above, the number of

fc

4

THE CHARCOAL IRON INDUSTRY. 139

ton units of heat necessary in the Scotia furnace may be approxi- mated closely enough for purposes of comparison :

Ton units of heat necessary : Units.

For reduction of the iron » 1697

" carbon impregnation 87

Expulsion of carbonic acid from limestone 65

Decomposition " u 243

Decomposition of water from blast and charcoal * 293

" " silica , 86

Fusion of the pig 330

" " slag..... •• 355

Transmission through the furnace walls 100

Carried off in the tuyere water 14

" " " gases 313

3582 In this case the hot blast furnishes :

7.604 tons X 325° X 0.239 586

Leaving - 2993

to be furnished by the fuel in the furnace. If 24 per cent, of the car- bon of the fuel were burned to carbonic acid, and 76 per cent, burned to carbonic oxide, this calorific power would be produced, while if the same quantity of carbon were consumed in the propotions given by Gruner for the carbon burned to carbonic acid and oxide, there would be produced 3.184 ton units. The necessary heat is therefore 9J per cent, of the ideally possible.

The record of the results reached by this furnace are confirma- tory of the view that the fuel consumption must approach very closely to the possible minimum. (For dimensions, etc., see plate 1.)

MIDLAND FURNACE. (SEC. 2, T. 37, R. 4 W., CRAWFORD COUNTY.)

The Midland furnace was put in blast April 10, 1875. From the accompanying section [Plate 2] it will be seen that in its construc- tion there are features differing from those ordinarily obtaining in the charcoal furnaces of this State; but the campaign was too short to determine how far these novelties were advantageous.*

The ore used was mined at the Ferguson bank (SWi Sec. 18, T. 34, R. 5 W.) near Salem, Dent county. The mean of two analyses (after

* This furnace has again gone into operation after changing form to that of the Scotia. Work was resumed in April of the present year (1877).

140 THE CHARCOAL IRON INDUSTRY.

calculating the small amount of ferrous to ferric oxide) gave the following composition for the ore:

Ferric oxide 81.942 per cent.

Alumina - 8.760 percent.

Silica 7.661 percent.

Lime 0.956 per cent.

Magnesia 0.964 per cent.

Sulphur , 0.038 per cent.

Phosphoric acid 0 173 per cent.

100494

Metallic Iron 57 36 per cent.

Phosphorus 0.056 per cent.

The ftux is a magnesian limestone containing :

Calcic carbonate- 51.931

Magnesia carbonate - 38.871

Ferric oxide and alumina 0.785

Insoluble matters -... 7.47S

besides 0.028 of sulphur and 0.050 of phosphoric acid (equivalent to 0.022 of phosphorus).

The Charcoal contained 4.97 per cent, moisture, and 8.65 of ash matters. The charge consisted of 48 bushels coal (say 864 pounds), 1,500 pounds ore and 450 pounds limestone (=30 per cent, of the ore). The average run of pig was twenty-two tons daily, and the consump- tion of raw materials per ton of produced iron was about 1.737 tons ore, 0.522 ton flux, 1.171 tons charcoal and 9.560 tons air. The blowing cylinder is five feet in diameter, with a four feet stroke ; the number of levolutions per minute is 25. The blast left the tuyeres (four in number) with a pressure of 2^ pounds ; hot blast was used, the tem- perature being, probably, about 325° C.

In a specimen of this pig we found :

Graphitic carbon 2.780

Combined carbon-.... 0.360

Silicon - 0.566

Manganese- 0.67$

Phosphorus trace.

Sulphur 1 0.028

Iron, by difference 95.593

100.000

A specimen of the slag, taken at the same time, gave a per cent- age composition as under:

Silica 41.675

Alumina.-. 13.439

THB CHARCOAL IRON INDUSTRY. 141

Ferrous oxide .................................................................................. 2.813

Lime ............................................................................................... 30.203

Magnesia- ................................................................................. i.... 9.343

Potassa ................................. . ...................... . .................................. 0.537

Soda- ............................................................................................ 0446

Calcium sulphide ............................................................................ 0.322

Phosphoric acid ............................................................................. 0.306

99.184

Phosphorous - ................................................................................. 0.133

Sulphur ........................................................................................ 0.143

The silica contains 22.221 of oxygen, and the aggregate of oxygen in the bases is 18.556; giving a ratio of 1 1-5 to 1, and showing the slag to be composed of singulo and bisilicates in the proportion of two of the former to one of the latter [or 2 (2 RO SiO2) + RO SiO2]. The production of slag per ton of iron would be by calculation 0.674 ton.

We have fewer figures for arriving at the heat requirements of the Midland furnace than for the others, but from the data above given the following may be calculated and will be approximately correct :

DISTRIBUTION OF MATERIALS IN THE MIDLAND FURNACE .

(Per ton of pig iron made.)

Iron. Slag. Gas.

Ore, 1.737 tons, containing:

Iron .......................................................... 0.960 ............

Oxygen- .................................................................. 0.411

Ferrous oxide- .............................. .................... 0.046

Oxygen- ................................................................. 0.005

Silicon ......................................................... 0.006 ............

Oxygen .................................................................... 0.006

Silica.- .....................................................

Alumina

0.303 Lime

Magnesia ................................................... J

Flux, 0522 tons, containing: Silica-

Lime.

0.288

Magnesia

Carbonic acid 0.220

Charcoal, 1.171 tons, containing:

Carbon 0.030 0.932

Water 0.580

Ash- 0.060

Blast, 9.560 tons (water, 0.554) 9.560

142

THE CHARCOAL IRON INDUSTRY.

Corresponding to this distribution of materials, and with the con- stants used before, we find :

Ton units of heat necessary .. 4,260

From which deduct units furnished by blast 743

Leaving to be furnished by 0.982 ton carbon of fuel 3,517

Of the given amount of carbon, 19 per cent, must be burned to carbonic acid, and 81 per cent, to carbonic oxide to produce the above named heat-units to be furnished by the fuel. If the carbon were burned as in the ideally perfect consumption, 4818 heat units would be produced, and the amount actually necessary is 73 per cent, of this ideal.

MOSELLE FURNACE. (SEC. 14, T. 42, K. 1 E., FRANKLIN COUNTY.)

This furnace was built in 1857, and is owned by Messrs. I. H. Brown & Co., of Youngstown, Ohio. It is located within three-fourths of a mile of Moselle Station, on the line of the Atlantic & Pacific Railroad. [For dimensions, etc., see plate L]

The ore used was mostly from the Benton Creek Bank, in Craw- ford county, (Sec. 32, T. 36, R. 5 W.), on the line of the Salem & Little Rock Railroad, (Description of this deposit is to be found in Report of 1872, pp. 134, et seg.) Some limonite ore from a deposit in the vicinity of and belonging to the furnace company, is also used. The following are the results of analyses of these ores:

Hematite.

Ferric oxide 92.486

Ferrous oxide 3.598

Alumina 0.916

Lime trace.

Magnesia 0.639

Silica 3.132

Sulphur.. '. 0.042

Phosphoric acid 0.007

Water...

Sulphuric acid

Limonite. 73.766 2.551 5379 1.116 0813 5.703 0106

10290

100.820

99.902

Metallic iron 67.530

Sulphur 0.042

Phosphorus.. , 0.003

53.630

o.na

None.

THE CHARCOAL IRON INDUSTRY. 143

The -flux is a magnesian limestone, composed as under :

Calcic carbonate 53.061

Magnesic carbonate 37.122'

Alumina and ferric oxide.. 1.531

Insoluble matters 8.410

100.133

It contains also, by special examination, 0.061 of sulphur and 0.015 of phosphorus (0.034 phosphoric acid). To six hundred pounds of ore in one charge, 150 pounds of flux (or 25 per cent.) and 22 bushels of charcoal are added. The charcoal contains 4.03 per cent, moisture and 2.24 of ash. From one hundred to one hundred and ten charges are made every twenty-four hours. The yield is from seventeen to twenty of pig iron daily, and the materials consumed per ton of iron are 1.651 tons of ore, 0.421 ton of flux, 1.094 tons of charcoal and 6.02& tons of air.

The results of analyses of the several grades of pig iron are given

below :

No. 1. No. 2. No. 3. Mottled. White.

Carbon, graphitic 1.860 2.608 1.012 0.812 0.346

Carbon, combined 1.683 0.632 2.604 2.021 3.338

Silicon notest. 0.459 0.634 0.413 1.556

Manganese 0.570 trace 0.154 0.185 0.095

Phosphorus trace trace trace trace 0.039

Sulphur * 0.150 0.099 0.065 0.177 0.112

Iron..., 96.202 95.531 96.392 94.514

100.000 100.000 100.000 100.000

The slag produced is, by calculation, 0.404 ton to the ton of iron,, and gives on analysis:

Silica 48.819

Alumina 4.093

Ferrous oxide 2.424

Lime 27.596

Magnesia 14.737

Soda 0.781

Potassa 0.650

Calcium sulphide 0.622

Phosphoric acid 0,277

99.999

Sulphur 0.276 per cent.

Phosphorus 0.120 percent.

Oxygen ratio of bases to acid 1: 13-5 nearly.

144 THE CHARCOAL IRON INDUSTRY.

DISTRIBUTION OF MATERIALS.

. Iron. Slag. Gas. Ore, 1.651 tons composed of:

Iron 0.952

Oxygen 0.308

Ferrous oxide 0.062

Oxygen 0.007

Silicon 0.015

Oxygen 0.015

Silica, alumina, lime, magnesia 0.077

Water 0.075

Flux, 0.421 ton, containing :

Silica 0.035

Lime 0.125

Magnesia 0.075

Carbonic acid 0.183

Charcoal, 1.094 tons containing :

Carbon 0.030 0998

Ash 0.023

Moisture 0.044

Air, 6.025 tons containing :

Oxygen , 1.386

Nitrogen 4.623

Water 0.016

The total number of heat units required per ton of iron is found to be 3,805, ot which the blast furnishes 464, leaving 3,341 to be pro- duced by the fuel. If 84-J- per cent, of the carbon were burned to cabonic oxide, and 15| per cent, to carbonic acid this calorific power would result; if, however, the carbon were consumed in the propor- tions theoretically adopted, 4,912 heat units would be produced; hence, the number of units required is equal to 67 per cent, cf the theoreti- cally possible amount.

BOULLINGER CREEK FURNACE. (SEC. 4, T. 39, R. 18 W; CAMDEN COUNTY.)

[For dimensions, etc., see plate III; and for character of deposit? furnishing the ores, see Schmidt, in report of 1872, 183 et seq.] The furnace used the limonite and specular ores of the Osage river district with an average furnace yield of sixty per cent, the ores being pre- viously calcined. A charge consisted of 600 pounds of roasted ore, 20 bushels (360 pounds) of charcoal and from 30 to 50 pounds of lime-

P£

Sgfe

THE CHARCOAL IRON INDUSTRY. 145

stone. The production was from 15 to 20 tons per twenty-four hours, with a consumption of 150 bushels (1.205 tons) per ton of pig.

PILOT KNOB FURNACE. (IRON COUNTY.)

[Plates III and IV.]

[Notes of Dr, Adolph Schmidt.] Roasting the ores is done with the charcoal braze (or fine charcoal from the charring) in heaps of thirty feet width, fifty-feet length and twenty feet height, containing 3,200 tons. The layers of ore, eighteen inches thickness, alternate with layers of the braze of from seven to eight inches thick; the heap burning from two to three months. A charge is made up of 22 bushels of charcoal, 760 pounds roasted ore, broken to nut size, and consisting of three-fourths Pilot Knob and one-fourth Shepherd Moun- tain and 17 pounds of raw limestone per hundred of ore (= 129 pounds per charge.) In a campaign of the furnace, lasting sixteen months and twenty-three days, there were produced 8,267 tons of pig, with the consumption of 910,000 bushels of charcoal, or 134 bushels per ton produced. In that time the average daily production was 16.4 tons. The iron is very grey, looking almost like coke iron. Pilot Knob ores do not melt as those from Shepherd Mountain, but the latter do not make enough cinder ; the best results are obtained with the mixed ores. The pressure of the blast is from 2-j- to 3 pounds ; the tempera- ture is between 700° and 800° Fah., and the air enters the fur- nace through three three inch tuyeres. The heating of the boilers and of the blast is done by the furnace gases ; the hot blast apparatus consisting of six rows of double pipes — one ton weight each and cast in one piece. The blowing apparatus consists of two upright blowing cylinders, four feet diameter and six feet long, the pistons connected by gearing with one horizontal steam cylinder, two feet diameter and five feet long. From six to eight revolutions per minute are made when the pipes do not leak. (For dimensions of furnace, etc., see plate 1V.J

IRON MOUNTAIN FURNACES.

(IRON COUNTY.)

[Plate III.]

[Schmidt's Notes.] The principal object of roasting is to facili- tate the breaking of the ore, and surface ore, which is partly small and generally easier to break, is often not roasted at all. There seems GR— 10

146 THE CHARCOAL IRON INDUSTRY.

to be a further advantage in the roasting, for it is claimed that a higher daily production can be reached by the use of such ores, which may be accounted for by the splitting up and softening by roasting, so that less time is required for reduction and carburretting. The roasting is done in a similar manner to that practiced at Pilot Knob.

There are two old furnaces, the western, No. 3, and the eastern, No. 2 ; the first holding from one hundred and fifty to two hundred bushels more than the other. Each has two tuyeres of 3 inches diame- ter. The blowing engine for No. 3 furnace has two cylinders, two and a half feet diameter each, and five feet stroke, with from 18 to 22 revo- lutions per minute. For No. 2 there are three cylinders, two and three-fourth feet in diameter and five feet stroke, and with from 12 to 15 revolutions per minute. The pressure of the blast for the latter is 4 to 5 inches of mercury, (2 to 2£ pounds,) and for the first, 3 to 4 inches of mercury (1£ to 2 pounds.)

The furnaces are now smelting only surface ores, which work harder and make a somewhat harder iron. The charge is made up of 700 pounds of raw ore, 70 pounds limestone and 20 bushels of char- coal, and runs gray iron. From 55 to 58 charges are made daily, giv- ing from 18 to 20 tons pig iron. The latter is increased from 1-J to 2 tons when roasted ores are used. Furnace No. 2 requires 124 bushels of coal per ton of iron, and No. 3,119 bushels. Both furnaces run very irregularly, making frequently mottled and white iron ; this is especially true of No. 2 furnace.

The Iron Mountain ores require a strong blast; they are apt to run dry, making too little cinder. The limestone used at the fur- naces, though being magnesian and of the same general character as that used at Pilot Knob, looks considerably purer, containing less green clay and less red silicious matter. This may partly account for the fact that much less of it is used in the Iron Mountain charges ; besides there are the further facts that the ores are richer and less attention is paid to the regular production of gray iron.

IRONDALE FURNACE. (WASHINGTON COUNTY.)

[From Dr. Schmidt's notes] — This furnace runs on Iron Moun- tain ores, in mixture with limonites from the Marquand or the Corn- wall banks in Madison county, or from Marble Hill, Stoddard county, or from several localities within two and a half miles of the works. The charcoal braze, of which from eight to ten per cent, are produced in the burning, is used for roasting the ores. A furnace charge is composed of 650 pounds roasted Iron Mountain ores, 70 pounds roasted

THE CHARCOAL IRON INDUSTRY. 147

limonites from the various localities, and 50 pounds limestone and 21 bushels of charcoal. One hundred and eight charges are made per day.

The limestone is quarried close to the furnace. It is magnesian and is rather cleaner than that used at the Pilot Knob furnace, but not so clean as the Iron Mountain flux.

The charring is done by contract, and at distances ranging from two, to ten miles from the furnace. A pit contains usually about forty cords and burns from twelve to sixteen days. A cord of wood — chiefly oak and hickory — yields from forty to fifty bushels of charcoal.

The blowing engine has a steam cylinder twenty-two inches, and one blast cylinder of five feet diameter, with six feet stroke. From ten to twelve revolutions are made per minute. The pressure of the blast is 4| inches of mercury in the engine room, and 3 inches at the furnace (1| pounds). The heating apparatus, (which, like the boilers is heated with the furnace gases) consists of two double ovens, con- taining each a double row of ten pipes, or forty pipes in the full ap- paratus. Each pipe weighs about nineteen hundred pounds ; the pipes are cast in St. Louis. The temperature is about the melting point of lead. (For form of pipes, dimensions and outline of furnace, see plate III.)

The furnace has two tuyeres (3^ inches diameter). A campaign lasts from nine to fourteen months, and ends with the smelting of the hearth stone, which is brought from the Cedar Creek quarries about six miles distant. Four taps are made in twenty-four hours. There is no stoppage at tapping, and the hearth is closed at once. The product is 22 tons daily, and the consumption of fuel is 125 bushels of charcoal per ton of iron made.

Attention is called to the fact that the production of iron is usually larger in reality than the furnace records show. This arises from the practice, in weighing each day, of noting only the thousands, and disregarding the hundreds that are over. There is also a wide range of values of the standards of weight, tending to complications and somewhat confusing in calculating ratios of products to raw materials. In furnace practice, one ton of limestone is 2,268 Ibs., and the same weight holds good for the ore and cinder ; a ton of iron is 2.240 pounds, and one ton of fuel equals 2,000 pounds. In the calculations on the preceding pages, the raw materials have been reduced to the standard ton for pig iron (2,240 Ibs). There are also great differences in the weights of charcoal ; at Iron Mountain a bushel of the coal is estimated as weighing from 18 to 25 pounds ; at Irondale from 22 to 28 pounds ; at Pilot Knob from 22 to 25 pounds, while at other localities

148 THE CHARCOAL IRON INDUSTRY.

the weights are from between 15 and 22 pounds. In such, almost in- extricable confusion, it was deemed best to select an uniform weight of eighteen pounds per bushel, for making comparisons of the fuel — consumption at the various furnaces, and reaching thereby results which, while they may be somewhat too low for some of the furnaces, probably are not widely different from the actual expenditures of char- coal necessary to the production of one ton of pig iron at the Missouri furnaces.

There are also differences in the readiness with which ores from different localities give up their oxygen to carbonic oxide. Thus the ores of the Atlantic and Pacific region are generally more easily reduced than those of the Iron Mountain district, the latter allying themselves more closely with the " strengfliissig," and the former coming near to the "leichtfliissig" ores of the German writers.* While this difference certainly does make itself felt in actual furnace experience and practice with Missouri ores, it can hardly be regarded as sufficiently well understood or established, nor as being of sufficient magnitude to enter as a factor in comparing the results of iron smelt- ing in this State. Ignoring this little understood, and in reality, triffling difference, the differences in the results of the various furnaces as far as regards the charcoal necessary to the production of iron must be sought for elsewhere.

It certainly seems that the time involved in those various reac- tions which result in the production of iron, must be only variable where furnaces, working under similar conditions respecting ores and fuel differ in height and other dimensions. Enlarging or diminishing the volume of the furnace, and thereby lengthening or shortening the period of working beyond normal limits, not yet defined, may cause less of calorific power by making the reactions between CO and the ore, and C02 and the carbon, less or more rapid, and thus destroy that balance, between the finally escaping carbonic oxide and carbonic acid, which has been hypothetically taken to represent the most advantageous combustion of carbon possible in the blast furnace. If the proper velocity of descent could be determined with accuracy and rigor, the proper proportioning of the height and volume of the furnace to the work to be done would become easier ; at present it is known that with similar ores it, must be less with coke than with char- coal, and hence, smaller sized charcoal furnaces have relatively larger

*On this point Bell writes (Chemical Phenomena of Iron Smelting, p. 422): "If, these words are to be taken in their literal sense of comparative susceptibility to fusion, their use, in my opinion, may lead to error. * * * The actual cause of lesser con- sumption of combustible in small furnaces, I have conceived and described as being d ue to difference in susceptibility of reduction, and not of fusion.'"

THE CHARCOAL IRON INDUSTRY.

149

production than the larger apparatus necessary for coke or raw coal. Hence, also, the reactions take place less rapidly in the latter than in the former, and a smaller weight of charcoal is necessarily consumed to the unit of iron than is practicable with the other fuels, while it also follows that, the necessary heat remaining about constant for the ton of iron however produced, more of the small weight of carbon in the charcoal must be burnt to carbonic acid (with its 8,080 heat units) to produce that heat effect than will be necessary with the larger weight of carbon in the coke. This last is corroborated by the results of analyses of gases from charcoal furnaces, always showing a much larger per centage of carbonic acid than do those of gases from coke furnaces.

These points connected with the rapidity of descent in the fur- naces will, perhaps, be more evident to a non-professional reader by an examination of the following table, which contains in the last col- umn the number of cubic feet of furnace room concerned in the pro- duction of one ton of iron in twenty-four hours, calculated from the data in the fourth and fifth columns :

FURNACE

FUEL.

BLAST.

Volume of fur- nace — cubic feet

Production per day — tons

o £L

ll

T §

: o^

O

o^c:

§|

^Tt (D

Maramec

Charcoal

Cold

1,045

13.8

1,221

75

Boulinger

Cold .....

1,030

17.5

1.205

60

Scotia

Charcoal

Hot ..

1,489

20.2

0.912

74

Midland .. ,

Charcoal

Hot

3,435

22

1.171

156

Moselle

Charcoal

Hot

1,191

17.5

1.094

64

Hamilton

Hot

Pilot Knob

Charcoal

Hot

1,889

16.5

1.079

118

Irondale

Charcoal ..

Hot ..

1,563

22

1.911

71

Iron Mt. No. 3

Charcoal

Hot

1,142

19

0955

60

Iron Mt. No. 2

Charcoal

Hot..

1,023

19.3

0.997

59

Mo. Furnace Co South St. Louis Vulcan

Coke and raw coal- Coke and raw coal- Coke and raw coal..

Hot

Hot Hot

6,461 5,514

6,328

9

35

33.7

2.375 2.457 2.615

155

187

Grand Tower

Coke and raw coal..

Hot

8,630

37.5

2.380

266

Big Muddy

Coke and raw coal..

Hot

8,100

33.2

2.279

243

150 THE CHARCOAL IRON INDUSTRY.

The last two are Illinois furnaces working on Missouri ores. The figures for them and for all the coke furnaces are taken from the notes of Dr. Schmidt (1872,) which were collected for the Geological Survey but never made public.* Even at this late date these notes possess so much value as to make them worthy of a more permanent and more accessible form. They are therefore produced here with but slight changes in the phraseology. The notes of the Illinois fur- naces are omitted.

\Dr. Schmidts Notes on the St. Louis Industrial District.'] SOUTH ST. LOUIS IKON COMPANY.

(CARONDELET.) [Plates V and VI.]

Two blast furnaces situated a few hundred yards south of Station 2, Carondelet.

Ores : Iron Mountain specular ore, principally ; surface ore and bank ore mixed, usually about one-third of the former, but not always in regular proportion. No difference has been noticed between these two kinds of ore, although the surface ore has never been run alone, while the vein ore has. Iron Mountain ore alone works too dry, and is therefore mixed with some brown hematite. About a year and a half ago, Pilot Knob ore was tried, but complaints were made of the lack of strength in the iron for foundry and for nail works. Brown hematite was not used at that time; the mixture contained twenty- five per cent. Pilot Knob ore. There was no considerable difference in the yield noticed.

The brown hematites come from Southeast Missouri, from the vicinity of Fredericktown and Marquand, on the Iron Mountain Rail- road. The soft, red hematites from the line of the Atlantic and Pacific Railroad are sometimes used to the amount of twenty to twenty-five per cent, of the charge. It is preferred for softer and purer irons. The same amount of flux is used for the red or the brown hematites ; the latter are used only when the red is not to be had.

Coal : Brazil, Indiana coal, reaches the works by the Indianapo- lis and St. Louis Railroad. Big Muddy coal, from Grand Tower, Illi- nois, is brought by boat one hundred and twenty miles up the river. When coke is to be had, it is mixed with the coal and improves the running of the furnace on grey iron. The coke comes from Connels-

*It was the intention of the writer to have emended these notes, bringing them clown to a later period, and to have illustrated the furnaces work by analyses of the materials and products. On account of the unfavorable condition of the iron industry this work was so long delayed that other laboratory work took precedence, and time did not allow its being completed to date.

56- >0"

HORIZONTAL SECT/ON.

HOT BLAST APPARATUS A T STHST LOUIS ISCHM/DT]

'LATE VI.

THE CHARCOAL IRON INDUSTRY. 151

ville, and the necessity of transportation by river renders the supply uncertain. Coke from East St. Louis is now being tried.

Blowing Engine — Old: One steam cylinder 34 inches diameter and 7 feet stroke ; the blowing cylinders, 16 inches diameter and 7 feet stroke ; two fly-wheels, 13 tons each, 18 feet diameter. Temperature of blast 800° to 900° Fah.; pressure, 4f pounds ; pressure of steam 80 to 85 pounds ; revolutions, 16. New Engines : Two, horizontal ; steam cylinders 29 inches each; two blowing cylinders, 72 inches, each; length of stroke, 6 feet ; one fly wheel, 12 tons.

Hot Blast Apparatus : No. 1, 16 feet wide, 25 feet long, with 65 syphon pipes, 12 feet high, and 5 bed pipes. There are therefore, five systems of thirteen pipes each. No. 2, 28 feet 4 inches long, 17 feet, 8 inches wide, with 78 syphon (12 feet) and 6 bed pipes.

Results for the year ending May 31, 1872.

Number of charges made 11,065

Fuel used :

Coal , 18,904 tons.

Coke 3,639 tons.

22,543 tons. Ores used :

Iron Mountain ,13,113 tons,

Tenn. brown hematite 241 tons.

Hermitage, red hematite CA. & P. K. E) 342 tons.

13,696 tons.

Puddle cinder 739 tons.

Flux 3,345 tons.

Product :

Foundry, No. 1 2,710 tons.

Foundry, No. 2 1,227 tons.

Foundry, No. 3

Mill iron, No. 1 4,441 tons.

Mill iron, No. 2.! *. 776 tons.

Castings 25 tons.

Total 9,179 tons.

[From the above the following are calculated : Yield of pig from the ore, 67 per cent.; fuel consumed per ton of ore smelted, 1.6 tons ; fuel, per ton iron produced, 2^4 tons; flux per ton of ore, 0.25 ton; flux, per ton of iron, 0.36 ton.— 0. P. W.]

[Dr. Schmidt's notes on markets, freights, etc., are, for obvious reasons, omitted. — 0. P. W.]

Missouri Furnace Company, (Plate VII,) July 5, 1872. Two blast furnaces situated near Station 2,'Carondelet, a few hundred feet north of the station. One furnace running, the other in repairs. Ores: Iron Mountain, arriving by I. M. K. R.; the cars are pushed into the

152 THE CHARCOAL IRON INDUSTRY.

shed, and in unloading the large pieces are separated by hand from the fine. The coarse ore is hoisted on an incline to a Blake breaker, and crushed to a fist size. No roasting of the ore; surface ore works equally well with the other. Pilot Knob ores have never been worked. Ten per cent, brown hematite, used, uncrushed.

Coal : Usually run with Big Muddy coal with one-fourth coke. Indiana coal is used only in case of necessity, but does not make so good quality of iron. Coal alone does not affect the quality of the iron, but the furnace is liable to hang and does not run so fast as with the mixed coal and coke, the latter giving from 30 to 45 tons of iron against 30 to 35 tons with the coal alone. Coarse coal works almost as fast as coke.

Connellsville or Pittsburg coke is used, reaching the works gen- erally by barges down the Ohio. Connelsville coke weighs about 38 pounds per bushel, and the cost by river transportation is 18 cents against 20 cents per bushel for the same by rail. The difference in the price is therefore $ 1,20 per ton , estimating 60 bushels to the ton.

Blowing Engine, etc. — One engine, two horizontal cylinders about 6 feet by 55 feet 3 inches, directly connected with steam cylin- der (29 inches [?]); 6 feet stroke; 25 revolutions per minute for one furnace, or 35 for two. Steam pressure, 70 pounds, but only 40 pounds are needed in the cylinders, the reduction being effected through the steam valve. The boilers are six in number, each of 40 feet length.

Hot Blast Apparatus : One system has four rows of eight or thirty-two syphon pipes; the other, six rows of eight or forty-eight pipes. Temperature of blast=900° Fah.; pressure 2^ to 3 pounds.

furnaces : Have eight tuyeres of four inches diameter. The two furnaces have the same dimensions, No. 1 has, however, a closed top.

Charge : For grey iron :

Iron Mountain ore (uncrushed) 2.500—3,000 pounds.

Cornwall (raw) " ) " ) 2,000—3,000 pounds.

Limestone , 20 per cent

Coal and coke, 6 barrows, at 10 bushels (of 64 Ibs each for coal or 35 Ibs for coke.)

The yield is 66 per cent, of iron from the ore, and the consump- tion of fuel is from 2J to 2-J tons of mixed coal and coke per ton of iron produced.

Carondelet Iron Works, near station No. 2, Carondelet: This fur- nace is under the same management and uses similar materials to those used at the furnaces of the Missouri Company. It was put up in 1852, as an experimental furnace, to test the smelting of Iron Moun- tain ores with raw coal. The furnace has a closed front, open top,

SO' 0 "

—

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1 i

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$ «"

^

THE CHARCOAL IRON INDUSTRY. 153

and has five tuyeres, none above the tymp. Its production is from eighteen to twenty tons daily.

The hot blast apparatus has two double rows, or about forty pipes (Scotch pistol-pattern). Temperature of the blast 600°-700°; pres- sure 2-J- pounds. Practice and results, the same as at the Missouri Company's furnace.

Vulcan Iron Works : The two furnaces of this company are run chiefly with Iron Mountain ore with ten per cent, puddling cinder. Sometimes mix Pilot Knob ores and sometimes brown hematites from Iron Mountain R. R., or Atlantic and Pacific R. R., or from Osage river (pipe ore) or bog ore from Southern Missouri or Arkansas. The proportion of Pilot Knob ore used is from one-sixth to one-fourth the weight of the Iron Mountain ore with which it is mixed.

The fuel is mixed Big Muddy and Indiana coal and Pittsburg coke — one third of each.

Both of the existing furnaces [July 10, 1872,] are alike, and have the dimensions indicated in the sections [plate VIII], Each has eight tuyeres. One larger furnace, eighty feet high and twenty feet bosh is being built, especially for Bessemer iron, to run with coke alone, or with coke mixed with a little raw coal.

Diameter of tuyeres, 4 inches ; temperature of blast 800° ; pres- sure, 2-J to 3£ pounds.

A charge is 1,500 pounds coal, 1,700 pounds coke, 3,300 pounds crushed ore (Iron Mountain) and cinder, and 1,000 pounds (== 30 per cent.) limestone. Forty charges are made in twenty-four hours to each furnace. The actual production is from 70 to 80 tons of iron from the two furnaces.

Puddling Kill ; Eighteen double furnaces ; charge 1,050 pounds, with five heats in eleven hours ; labor, five men to a furnace; fuel, forty bushels of Belleville, Illinois, coal to the ton of puddle bars.

For head plates for rails, the following mixture of irons is used: 1-6 Tennessee charcoal, (Wayne furnace) ; 1-6 Wisconsin charcoal iron ; -J- Iron Mountain charcoal, and £ Vulcan Iron.

Rail Mill, has ten heating furnaces and twenty two inch trains with a capacity of 90 tons of finished rails in twelve hours. The en- gine is 350 horse power.

The consumption of fuel for puddling, heating and all purposes is eighty bushels to the ton of finished rails.

The analytical results relating to the charcoal furnaces are col- lected on the following two pages, for convenience of reference. They include the analyses of the fluxes employed, of the slags pro- duced, with the oxygen ratios, and of the several grades of pig iron manufactured.

154

THE CHARCOAL IRON INDUSTRY.

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THE CHARCOAL IRON INDUSTRY.

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SHANNON COUNTY

AND ITS

COPPER DEPOSITS.

SHANNON COUNTY.

GEOGRAPHY, TOPOGRAPHY AND HYDROGRAPHY.

Shannon county, situated in the southeastern part of the State, i& bounded by the counties of Reynolds and Carter on the east, by Ore- gon county on the south, by Howell and Texas counties on the west, and by Dent on the north. Its northern limit is township line 32 ; its southern, the northern line of the lower tier of sections in township 26; its western boundary is in range line 7, while easterly its outline is irregular, but its limits are chiefly to the west of range 3. It in- cludes twenty-six townships, and thirty-four sections, or an area of 980 square miles.

The surface of the county is broken and hilly, the hills rising abruptly or precipitously, and rarely with an approximation to a gentle slope from the streams. On Sec. 28, T. 30, R. 4 W., barometric observations gave the summit a height of 350 feet above the level of Current river, distant less than one-half mile ; in sections 9, T. 29, R. 4 W., the elevation is 400 feet above the Current.

The largest stream is the Current river, entering the county in Sec. 5, T. 31, R. 6, and flowing with a very tortuous course, but in a general southeast direction, enters Carter county in Sec. 16, T. 28, R. 1 west. It is a rapid-flowing and clear stream, with a narrow fertile valley, limited by abrupt hills, often with steep mural faces. Its chief confluents are Barren Creek and Jack's Fork of the Current. Barren Creek enters Shannon county from Dent in Se<3. 6, T. 31, R. 4 W., and flowing a general southerly course, discharges into the Cur- rent on Sec. 7 in the next township south, after receiving, in Sec. 33, T. 31, R. 4, the waters of Sinking Creek. Jack's Fork enters from Texas county (on Sec. 31, T. 28, R. 6,) and with a general northeast- erly flow, joins the Current in the S. E. i of Sec. 9, T. 29, R, 3, after receiving the waters of the Delaware and Big Shawnee creeks, both flowing from the South.

Besides the main water courses enumerated, the county is abun- dantly supplied with smaller streams and brooks, along the narrow

160 ECONOMIC GEOLOGY OF SHANNON COUNTY.

bottoms of which excellent farming land is found. All these are quickly flowing streams, and many of them furnish fine power, which must eventually be utilized for the manufacture of lumber from the heavy growths of yellow pine and other woods with which the hills and creek bottoms are clothed. Two of these small streams are of sufficient interest to warrant a special description.

Blue (or Hound) Spring, on the northwest quarter of Sec. 20, T. 30, K. 4 west, rises in a circular sink or opening in the limestone rock. The spring has a diameter of 84 feet, and careful soundings reached a maximum depth of 48 feet. The water is of a pale azure blue — pos- sibly due to the polarization of light by the finely divided limestone or clay in suspension — and has a temperature of 58°5 Fah., that of the air being 80|°. It has a subterranean outlet through 72 feet of limestone, after which the waters discharge themselves into Current river, at a distance of 660 feet measured on the course of the stream with a fall of 17 feet. The volume of water discharged by this inter- esting spring we may estimate from the accompanying plan and sec- tions (from a careful survey in August, 1875,) to be not less than 425 cubic feet per second, or an available horse power of about 800. The origin of this spring must be looked for in some of the sub- terranean water courses which are known or believed to exist in the vicinity.

Mammoth Spring (west i S. E. i, Sec. 25, T. 29, R. 5 W.) appears near the base of an almost perpendicular bluff which has a height of 159 feet (by the barometer) above the present surface of the water in the dam. The bluff rises by a gentle slope, 95 feet more to its sum- mit. The water has a temperature of 57° Fah., that of the air noted at the same time being 80°. It has the blue tint, but not so well marked as that of Blue Spring. A line of soundings from the base of the bluff to the dam gave the following depths: 31 feet, 30 feet, 31 feet, 27 feet, 19 feet, 15 feet and 10 feet. The surface velocity of the stream, determined by the time required for a float to pass an accu- rately measured distance of one hundred feet, near the line of cross section of the stream (see plan and section of Mammoth Spring, Plate X), was 5.38 feet per second.* The volume of water discharged

must be at least 588 cubic feet per second, giving horse power.

GENERAL GEOLOGY.

Arckean : This age is represented in the limits of Shannon county by the so-called poryphyry rocks of various textures, gener-

* The observations were 18", 19", 19", 19" and 18" for the one hundred feet ; mean, 18."6. The observations and the survey of this and the Blue Spring were made chiefly by Mr. John McGuire, a most faithful and competent assistant, who was with me in Shannon and other counties.

ECONOMIC GEOLOGY OF SHANNON COUNTY. 161

ally compact, however. They contain little or no free or visible quartz are highly feldspathic and generally micro-crystalline in structure, cor- responding in these particulars to the rocks classified as porpliyrite in the nomenclature proposed by Naumann, the crystals not being large enough or sufficiently well-defined to place these rocks among the true porphyrys, as the word is understood. In fact, the term is applica- ble only to rocks of certain structural peculiarities, not confine.d strictly to any special mineralogical composition, and is therefore apt to cause error when used to denote the latter instead of the structu- ral character. However, as the name porphyry has been used to describe certain rocks in Iron county, which are closely related, in physical features at least, to those of Shannon county, and has there- fore become somewhat specific in application, it is deemed best to retain it in this connection.

The color of these rocks ranges between a reddish brown and a dark pink ; masses of a flesh-tint are occasionally met, and others with a dark liver-color are still more common. They break usually with a smooth fracture, inclining at times to choncoidal.

The absence of distinctly crystalized feldspars in these rocks makes the determination of their mineralogical composition some- what difficult. A specimen with a dark brown color, showing a few patches or specks of lighter color scattered throughout, but of very hard and compact texture, from N. E, qr., Sec. 36, T. 29, R. 4 W., on being treated with hydrochloric acid yielded material amounting to 12.216 per. cent, of the rock (including 0.651 of loss by ignition, which belonged to this portion,) which, on analysis, was found to con- sist of:

Silicic acid 37.27 per cent.

Ferric oxide 42,19 per cent.

Alumina 429 per cent.

Lime 1.74 per cent.

Magnesia 4.80 per cent.

Soda 1.19 per cent.

Potassa 3.12 per cent.

Water 5.38 per cent,

9998

Giving an oxygen ratio for the bases, silica and the water of 4 : 4.5 : 1. It is probably a variety of the uncertain species, pinite, and a product of alteration ; but is interesting from the relatively large amounts of ferric oxide and small amount of alumina. Part of the iron may exist, however, as a mechanical mixture, and the decom-

G R— 11

162 ECONOMIC GEOLOGY OF SHANNON COUNTY.

position of which this material is the result, may have been aided by the sulphides existing in these rocks.

The portion of the rock remaining unaffected by boiling hydro- chloric acid, was of a paler color, with a tint somewhat inclining to purple, and after drying at steam heat, constituted S8.226 per cent, of the original rock. It contained no water, and yielded by analysis :

Silicic acid .,. 73.11 per cent.

Alumina ... 1426 percent.

Ferric oxide 1.08 per cent.

Lime. 0.31 per cent.

Magnesia ~.. trace

Soda trace.

Potassa 11.08 per cent.

99.84

The oxygen of the sesquioxides (alumina and ferric oxide) stands to that of the protoxides (potassa and lime) in the ratio of 3.4 to 1, while the ratio in the feldspars is 3 to 1. The mineral is an orthoclase felsite, a portion of the potash having been removed by decomposi- tion. The analytical results point to the view that the original rock was a mixture of albite and orthoclase felsites, the latter preponder- ating. The decomposition has been most active in the soda feldspar, this being more readily decomposed than the potash or orthoclase feldspar.

The bedding of this rock is obscure, and the differences in litho- iogical features and in texture are so very slight that there are great difficulties in the way of arriving at a knowledge of the structure of the region in question. However, on section 36, there are three par- allel intercalations of a white quartzite rock, having a strike of about N. 37° E— S. 37° W., and dipping S. E., 56°— determined in the shafts and other openings on the copper deposits occurring in connec- tion with these quartzite beds. Commencing with the most south- easterly of these, we find it to be about twelve feet thick, and to rest on 18 feet of a decomposed porphyry of a dark brown color, under which is the second belt of white quartzite, resting on 130 feet of por- phyry somewhat decomposed (sample for analysis above given was taken from this bed). Below this is the third quartzite bed resting on porphyry, which is of a paler color, but with a purple tint, and is of compact and massive texture. If bedded at all, the bedding is on a large scale.

The white quartzite from bed II, is enfilmed in patches with green stains, probably of malachite, and yields, by analysis, 0.058 per cent, copper (equivalent to 0.104 per cent, malachite). It, and the material

ECONOMIC &EOLOGY OF SHANNON COUNTY. 163

from the other quartzite beds, contains, especially in the seams, a white clayey material decomposable by acids, which amounts in the -case of No. II, to 15.8 per cent, of the weight of the material, and con- tains silica, alumina, a trace of ferric oxide, lime, magnesia, soda, car- bonic acid and water. Of the remaining 84.2 per cent, of the rock, "96.9 per cent, is silica, the three remaining per cent, being made up of alumina, ferric oxide and lime.

The copper deposits exploited on Sec. 36 are beneath the belts of white quartzite, resting on felsite.

Silurian. The rocks of the calciferous epoch make up the larger part of the county. They rest unconformably on the porphyry, which forms the substructure of the region, covering the latter, excepting at few points, which were islands or peaks above the surface of the waters of the Silurian sea. The most recent member is the second sandstone, showing on Sees. 1 and 2, T. 28, R. 5 W., with a thickness of somewhat less than fifty feet; on Sec. 9, T. 29, R. 5, and on the road from Blue Spring to Eminence, on Sec. 9, T. 29, R. 4, with about the same thickness. At the last named locality its height above the Ourrent river is 400 feet. On section 38, T. 30, R. 4, the third magne- sian limestone rock forms the entire hill from its base on the Current river to its summit, 350 feet above the river.

The heavy belts of this third limestone approach very closely to a true dolomite in the relations of the calcic and magnesic carbonates, as shown by the following analysis :

A. B. Mean,

per cent. per cent. per cent.

Calcic carbonate 55.313 55.216 55.264

Magnesic carbonate 42.532 42.374 42.453

Ferric oxide and alumina 0.964 0.916 0.940

Insoluble matters... 1.384 1.330 1.357

100.193 99.836 100.014

Deducting the insoluble matters and the ferric oxide and alumina {== 2.297 per cent.) and calculating then the percentages of calcic and magnesic carbonates, they will be found as follows :

Calcic carbonate 56.56 per cent.

Magnesic carbonate 43.44 per cent.

whilst the molecular proportions of true dolomite require :

Calcic carbonate 54.35 per cent.

Magnesic carbonate 45.65 per cent.

The magnesic carbonate in the specimen examined is slightly excessive.

164 ECONOMIC GEOLOGY OF SHANNON COUNTY.

ECONOMICAL GEOLOGY.

Copper. The occurrence of deposits of copper ores in the por- phyry, and their position on Sec. 36 has already been noted. The existence of these deposits at this locality has been known since the year 1830, when Joseph Slater began mining operations, which resulted in the production of fifteen hundred tons of copper ores, it is said, which were shipped to Swansea or smelted on the location. A period of litigation seems to have followed, lasting until the year 1841, when the Aberdeen (Scotland) Mining Company came, in possession and resumed work. Through what cause this company ceased operations I am not advised, but the property came into the possession of the Current River Mining Company, and by them transferred within the last three years to the present owners, the Consolidated Land Com- pany of Missouri, whose estate comprises about nine thousand acres in Shannon county.

About the year 1841 this section of country was visited by Mr. James T. Hodge, and his views were published in Silliman's American Journal [XLIII, 65.] According to Whitney,* who bases his opinion on Hodge's Report, the ores appear to be contact deposits between lower silurian rocks and a reddish quartzose porphyry of azoic age. At the time of my examination (1875), the older works were not in condition to admit of making such an examination as would warrant a positive opinion as to the nature of these deposits, but from the access to them, which was permitted by the cleaning up work of the present company, they seemed to be rather of the character of bedded veins, coincident in strike and dip with the bedding of the porphyry,, and associated with the white quartzite above noted, as the hanging wall. It is possible, however, that they may be classed as vertical seggregations or vein masses (stehende stoectce, Cottaf) between the felsites proper and the white quartzites. More extended working is necessary before the true character of the deposits can be fixed.

The accompanying diagram (Plate XI) and section of the part of section 36, on which the works have been concentrated, will show the positions of the deposits and the principal shafts which have been carried down to develop them.

The ores in the upper parts of the deposits are almost exclusively oxidized ores, or Secondary products from the sulphides. The anogene metamorphoses which have resulted in the production of such consider- able amounts of the carbonates and oxides from the sulphur combina-

* Metallic Wealth of the United States, 311.

f Die Lehre von den Erzlagerstaetten, pp. 191, et. seg.

CROSS SECTION ON E.F.

VerlicatScalefbr Sectio

Tfc-

xi. PLAN AND SECTION or COPPER PROPERTY.

KWV* efX£fr <tye.J#.7:2,9rt. SHANNON COUNTY.

ECONOMIC GEOLOGY OF SHANNON CODNTY.

165

tions, and in the simultaneous liberation of so much sulphuric acid, must have played no minor part in the alteration of the felsites which has been described. It may be that the beds of white quartz themselves, possibly owe their existence to such action, they being final products from the felsites after the elimination of the basic constituents there- from. If these hypothetical considerations are well founded, the geog- nostic history of the copper deposits would be made up of the following periods : (1) formation of a fissure along a line of bedding in the por- phyry ; (2) repletion of this fissure by sulphides of copper and iron — these being cathogen operations — and, (3) oxidation of the sulphides and formation of the carbonates and oxides, with the simultaneous production of the beds of white quartz and partial decomposition of other beds of felsite.

The gangues are almost entirely silicious ; at times small amounts of calcite and dolomite are found, and limonite occurs intermixed with the carbonates of copper, and coating larger lumps of the yellow sulphide.

The following analyses show the composition of the "carbonate ore" from this property :

i.

Cupric oxide 70.800

Ferric oxide 3.463

Lime 1.035

Magnesia 0.650

Carbonic acid 16.640

Water 7.050

Sulphur 0876

Silica... 0.363

II.

70.641 4.073 0.845 0.192

16.523 7.037

not est 0.382

Less oxygen equivalent to sulphur.

Metallic copper

100.876 437

100.439 56.61

56.52

III.

70598 3749 0.804 0232

16.331 7.126 1052 0.468

100.360 526

99.834 56.42

The analyses were of a sample of several large pieces. No. I is the mean of two analyses by Ohmann-Dumesnil; II, mean of two by James Pack, and III, single analysis by Gavens— all in this laboratory.

The sulphides at present produced are chiefly from the cleaning up of the old works, no deep or systematic mining having been begun at the time of our visit. The larger lumps are composed of chalco- pyrite(=copper pyrites) intermixed with brown iron ore (limonite), a small amount of malachite and more black oxide or melaconite. Two samples were analyzed at my request by Mr. John D. Greason with results, as follows :

166 ECONOMIC GEOLOGY OF SHANNON COUNTY.

A. B.

Cupric oxide 28.207 69.001 per cent.

Ferric oxide 45.660 4.049 per cent.

Alumina nil. trace.

Lime 0.430 1.881 per cent.

Magnesia trace. 0.198 per cent

Arsenic nil. trace.

Antimony 0.070 nil.

Sulphur 13.669 3.908 per cent

Carbonic acid 1.562 11.906 per cent

Water 5.462 13.409 per cent

Silicious matter 5.539 0.259 per cent.

Metallic copper 22.52 55.16 per cent.

The mineralogical composition of A may be calculated from the above analysis to be probably, as follows :

Chalcopyrite 39 165 percent.

Malachite 2.769 percent

Melaconite 12.487 per cent

Limonite 33.414 percent.

Gangue 5.969 per cent.

Samp)e B shows less chalcopyrite, and more malachite.

The first shipment of ore made under the present organization amounted, I am informed, to 36,213 pounds. It was obtained in the work of cleaning up and exploration, and included 546 pounds of furnace bottoms and regulus from the old works. Of the remainder, about one-half was lump or cobbed ore, and the other, sand or wash ore, yielding respectively, 32 per cent, and 12 per cent. It was treated at Wheatleys' works, near Phoanixville, Pennsylvania, the route of shipment being by teaming to Mill Spring station, on the Iron Moun- tain Railroad, (at a cost of sixty cents per hundred), thence to St. Louis and eastward. These figures are furnished me by Chas. T. BiserT the superintendent of the works, who claims that the Iron Mountain Railroad can be reached, at Newport station, at a cost not exceeding three dollars per ton by flat-boating down Jack's Fork and the Current river.

The limestone near the line of junction with the porphyry shows small amounts of copper, chiefly in the form of malachite stains. These occurences are probably of the class of impregnation zones,, and can hardly be regarded as of any practical significance. The Biser shaft (on S. E. qr. of S. E. qr., S. 25, T. 29, R. 4), was carried down to a depth of 70 feet, through limestone, without reaching the por- phyry. Coarsely crystallized calcite and dolomite were met, and occasional specks or stains of malachite.

ECONOMIC GEOLOGY OF SHANNON COUNTY. 167

Iron : Deposits of hematite of the variety known as blue specu- lar ore, are found in the sandstone. A specimen from Sec. 2, T. 28, R. 5 W., gave 96.205 per cent, ferric oxide, (=67.31 per cent, metallic iron); 0.893 per cent, alumina; 0.105 per cent, lime ; traces of mag- nesia and phosphoric acid ; 0.018 per cent, sulphur, and 2.080 per cent. silica=l 00.101. 'Material freed from hygroscopic water, by drying at 102°0. before analysis.

The variety of hematite known as micaceous ore is found in small seams in the porphyry. It is said to be titaniferous, but I have seen no analysis, nor have I deemed the matter of sufficient practical im- portance to make the examination myself. The little streams running: over the porphyry show black iron sand.

Lead : Explorations for lead have been made at several locali- ties, in the magnesian limestone, and in the vicinity of the Blue Springs, on the opposite side of the Current. Some little galenite, largely intermixed with pyrite, was found. Galenite is reported as having been found at other localities in the county, but in no large amount, nor have any deposits, as yet, been opened. The occurrence of the third magnesian limestone — a notable lead-bearing formation- is some foundation for the expectation that lead may be found, but it should be borne in^mind that the discovery of the coarsely crystal- lized calc spar or " glass tiff" is in itself not sufficient incentive to explorations for lead, even in the third magnesian limestone. This mineral is found largely in the limestones of southeastern and southern Missouri, and has been the cause of considerable outlays of time and money, made in confident expectation that it was invariably asso- ciated with lead ores.

APPENDIX A.

LEAD AND ZINC STATISTICS.

LEAD STATISTICS OF MISSOURI.

(ST. LOUI£ MERCHANTS' EXCHANGE REPORTS.)

Lead Importations to St. Louis for the Twenty Years from 1856 to 1876.

YEAR.

TOTAL POUNDS.

YEAR.

TOTAL POUXDS.

1856

16,372,840

1866

11,966,720'

1857 .

13 004 400

1867

11,564,400

1S58

25 311,760 i

1868

14,865,840'

1859

21,150,400

1869

18,264,240

I860

19 059 280

1870 ;

18,963,120

1861

9 220,720

1871

18,369,880

1862

7 664 000

1872

22,861,520

1863

6 385 840

1873

28,482,960

1864

7 442 800 '

1874

38,357,840

1865

9 330 880 i

1875

46,336,160

Total ..

364,975,600

Distribution for Two Years.

Home consumption in 1874.

Export in 1874

Home consumption in 1875. Export in 1874

21,536,000 pounds. 16,821,840 pounds. 29,600,000 pounds. 17,736,160 pounds.

172

APPENDIX.

Total pounds...

C\| CO CD ^* CO ^t* CD rH CO CD C^ ^

CIrHOCOCit-r-iOCOCOCOiO

GO r-l r-l 10 t- CO Ci cT 00~ b- O O

1 W

Other sources —

§ 1 1 1 1

r-l 0 CO f- (M

O O r-l -f

«v .

Missouri, Kan- sas and Texas E. E. — pounds

§• §

i S @ §

• • «s

Illinois E. E.— pounds

O O

% i

c

§0000 CO CM TP CO

8 i

0 IT

g

*

CO rH O CO CO

s § * s ^

rH

St. Louis, Kan-

1 1 § 1 1 1

sas City and Northern-p'ds

CO r-l rH C3 CM GO O O CO <M O t- VO O i— * t-— O OJ

rH rH TP G^ rH

Missouri Pacific E. E. — pounds

8 S

GO GC

r-

!T}^ C<I CM O O CO O CO CO Tt< CO O

co" •"** co" f>T i^ co"

CO Q5 O Oi CN r-i CJ r-i l^ CO r-i CO

Atlantic and Pacific E. E.— pounds

§0 0 CM t-. CM CO CO CO O CO

III1 § «

CM" co" rjT

Iron Mountain R. E.— pounds

11!

CD CD GO CD O CD CD CD CO CD <O CO CO CO C^l CD lO CD GO rH rH CO t>— CO

'

283

T{iCO'^COOrHT^CO

co co co CN t— o co Oi

OO(MrHG^COt>.CO

CO r*< T}

r-t rH rH

Missouri Eiver —pound0..

^ Tt C1? CO Tf CN|

CO Tt< OS L- CO I-'

CO CO t-- CO <M CO O O rH O <M

Lower Missis- sippi — pounds

CM O ' -* O O O CO I

g g g

r-l r-

O O O ^

[ g a a • a i

1

Upper Missis- sippi—pounds

CD CD O> CD CD CD CD CD O CD O

Or- «COOCiCJ-OOC5<7Jb-

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COCOGCCOCOCOQOCO

APPENDIX.

173:

Partial Report of Mineral and Pig Lead — 1875.

COMPANY.

COUNTY.

MINERAL— POUNDS.

LEAD — POUNDS.

Davis & Murphy .«

Jasper ... ..

2 250 000

3 440 000'

Pichar & Bro

3 328 960

40 000

Joplin M. and S. Co Lone Elm M. and S. Co

Jasper .

3,820,066 7 142 836

240,000 5 980 000'

Porter & Dorsey

3,464,582

1,GOO 000

Granby M. and S Co.. . .

Newton ...

35 606 400

9 goo 000'

Dade

500,000

297 797

Christian

175 000

"Webster

150,090

Greene

50 000

Lawrence . . ...

4 000

Palmer

Washin ^ton

1 , 748, 430

1,262.222;

^Vashington « .

1 250 OCO-

John Evens

320 000-

Other sources

Washington ..

293 720*

St. Joe

St. Francois

4 960 OOfr

O^a^e Company

Miller

380 000

374 580'

Total...

32.954.519>

174

APPENDIX.

Prices of Lead at St. Louis, for 20 years, from 1853. [Compiled from various sources.]

1856

$6 22

1866

$1Q 00

1857 .

6 00^

1S67

9 00

1858

5 20

1868

9 00

1859

o 25

1869

8 75

1860 ....

5 25

1870

7 25

1861

5 25

1871

7 00

1862

6 50

1872

6 874

1863

8 62£

1873

6 874

1864

12 SO

1874

1865

10 00

1875

6 664

Prices psr 100 pounds of Sojt Missouri Leads, by Months, jor 1875.

$6 62J

\ July

$6 50

February..

6 62£ to 6 75

August

C 75

March

6 00 to 6 75

I September..

6 75

to 6 87]

April..

6 25 to 6 50

October

7 00

May...,

6 25 to 6 37J

November

7 00

June..

6 37£ to 6 50

December

7 00

to 7 25

Prices of Hard Lead, for last Quarter of 1875.

October ,

$6

10

per hundred.

November

r>

?.">

per hundred.

December

6

20

per hundred.

ZINC STATISTICS

Production of Zinc Ores for 1875.

TSTewton county .-...• 8,500 tons.

Jasper county 4,000 tons.

Dade county , 6,500 tons.

'Greene county » 50 tons.

"Washington and other counties 4,500 tons.

Total 23,500 tons.

Consumption of Missouri Zinc Ores for 1875.

>Iartindale Zinc Company 7,800 tons.

^Missouri Zinc Company 4,200 tons.

"Carondelet Zinc Company 3.000 tons.

For Oxide production in Missouri 800 tons.

•Other furnaces outside the State.. 7,750 tons.

Production of Spelter in Missouri for 1875.

'Martindale Zinc Company , 2,200 tons.

Missouri Zinc Company | 1,500 tons.

'Carondelet Zinc Company 950 tons.

Total 4,650 tons.

176

APPENDIX.

Production of Zinc in the United States for 1875.

Lehigh Zinc Company, Pennsylvania 1,505 tons.

Passaic Zinc Works, New Jersey 600 tons.

New Jersey Zinc Company, New Jersey 700 tons,

Bergen Point Zinc Company, New Jersey 500 tons.

Matthiessen & Hegler Zinc Company, Illinois 3,500 tons.

Illinois Zinc Company, Illinois 1,518 tons^

LaSalle Zinc Company, Illinois 1,329 tons.

Pvobert Langen & Co Zinc Company, Illinois 331 tons.

Martindale Zinc Company, Missouri 2,200 tons.

Missouri Zinc Company, Missouri 1,500 tons.

Carondelet Zinc Company, Missouri 950 tons.

Chicago Zinc Company, Kansas 600 tons.

Reworked Zinc 600 tons.

Total 15,833 tons-

Production of Zinc in 1875, by States.

Pennsylvania 1,505 tons.

New Jersey j 1,800 tons.

Illinois.. | 6,678 tons.

Missouri 4,650 tons.

Kansas 600 tons.

Total • 15,233 tons.

Reworked 600 tons.

Stock on hand January 1, 1875 135 tons

Importations during 1875...., j 540 tons.

16,508 tons.

Stock on hand January 1, 1876 145 tons.

Total consumption for 1875 | 16,363 tons.

I

APPENDIX.

177

Gold prices per hundred pounds of Common Silesian in New York^ on December 31st, of

following years :

1866

$6 50

1871

$6 25

1867

6 37*

1872

6 37*

1868

6 25

1873

7 00

1869

6 18f

1874

6 87£

1870

5 S7£

1875

7 ISf

GR— 12

APPENDIX B.

NOTE ON THE OCCURRENCE OF GOLD IN NORTH MISSOURI.

APPENDIX B.

NOTE ON THE OCCURRENCE OF GOLD IN NORTH MISSOURI.

The summer of 1875 witnessed somewhat of an excitement in some of the counties of North Missouri, concerning the occurrence of gold-bearing deposit?. The wide-spread notices of the reported dis- coveries in the neighborhood mentioned were considered of sufficient importance to warrant a reconnoissance of the reputed auriferous region, and accordingly at the request of Governor C. H. Hardin, such was made in October 1874.

The occurrence of gold in the drift of North Missouri in small quantities has been noted by Broadhead,* and the distribution and the character of this drift has been described by the same authority and by other members of the surveys. The wide distribution of the precious metal in small amounts has been long known to chemists, and has become a matter of scientific interest rather than one of any practical significance. Messrs. Dubois and Eckfeldt,f assayers at the U. S. Mint, have described this natural dissemination of gold, and have collected some curious facts, among which maybe cited that the clay underneath the city of Philadelphia contains one part by weight of gold in every 1,224,000 or L grains (=$0.03) per cubic foot. In citing these results, GanthJ adds : uStill more astonishing — but unfortunately equally devoid of practical value — would have been the results, if the gravel which underlies this auriferous clay, and which is always richer than the clay above it, had been examined for gold."

The occurrence of gold in the materials of drift origin being therefore already admitted, and the distribution of the drift having been described by the geologists of the survey, there remained only the necessity to establish the amount of the gold in the drift at the localities where, among some, the expectations were high that the precious metal might be profitably extracted. The following addressed to his Excellency, Governor C. H. Hardin, under date of November 17, 1875, has already been made public :

The gold is contained in a gravel or drift material foreign to the locality, the underlying rock formation being carboniferous, and unal-

* Report, 1873-1874, page 47. I J Preliminary Report Mineralogy of

f Proc. Am. Phil. Soc. viii, 273. | Pennsylvania— 4.

182 APPENDIX.

tered. This precludes the possibility of gold veins. The gravel is dis- tributed pver a wide area, attaining a thickness in the county named [Macon] of upwards of sixty-four feet and consists of sands, marly or calcareous clays, and rounded pebbles or boulders, chiefly of quartzite, granite, porphyry and greenstone, the origin of which was in some locality which in all probability was auriferous. The fact in connec- tion with the wide distribution of the gravel dismisses at once the idea of artificial agencies in connection with the occurrence of gold in the locality.

The large amount of this gold-bearing material, and the circum- stances of its origin being understood, it seemed to me that all that remained to be determined were the probabilities of its being eco- nomically or profitably worked. To reach this knowledge, steps were taken to establish the quantitative relations of the gold to the con- taining gravel.

Samples representing seven localities at Murray's Gulch, £« , T. 60, R. 16, and aggregating seventy-three and one- quarter pounds were collected, and treated carefully by amalgamation. The follow- ing are the results : -

Amount taken in experiment, 25,600 cubic centimetres weighing 73.25 pounds avoirdupois. Sieved with a sieve of eight holes to the linear inch, giving 8,000 cubic centimetres of coarse pebbles, weighing 32.5 pounds or 44.36 per cent, of the weight of the orignal drift. A sample of the pebbles gave no trace of gold.

The material passing through the sieve was amalgamated and gave .0046 grammes of bullion.

The tailings collected weighed 25.65 pounds (dry) equivalent to 35.02 per cent, by weight. Three assays gave respectively 4-10, 45 100 and 45-100 ounces of bullion per ton of tailings.

A cubic foot of the moist drift as received at the laboratory weighs 97^ pounds.

The bullion obtained was 711— l,000ths fine.

The above data gives the following for the value of one ton of 2,000 pounds of earth :

Gold 58.13 grains or $2 51

Silver 9.57 grains or 0 03

Total 67.70 $0 03

or at the rate of $3.25 per cubic yard.

Under circumstances where large quantities of earth can be readily handled, with abundance of water and great fall of the water, an amount considerably below this can be profitably worked. Nei- ther of these conditions obtain in the region in question.

The distance of the drift from its place of origin would lead us to

APPENDIX. 183

expect that the gold would be of the character of small particles of the shape and weight best suited for long suspension in water, a mode of occurrence which would greatly increase the difficulties of extract- ing by mechanical processes, even were the topographical conditions favorable for such. The results of panning the drift of Macon county make it evident that the gold exists in fine particles, and almost entirely in the form of " scale gold," which it would be difficult, if not impossible, to save by the process of washing.

This is substantiated by a second experiment in which 1.76 cubic feet or 176£ pounds from six localities in Lilly's Gulch (about six miles northwesterly from the locality of the material of the first ex- periment,) were passed through a "rocker" by an experienced hand, and concentrated up to 12-J ounces of fine material. This amount was divided into three unequal parcels, (for convenience in assaying) and an assay gave as follows :

JFirst lot from rocker 0.0018 gramme.

Second lot from rocker 0.0092 gramme.

Third lot from rocker 0.0025 gramme.

Total gold in 12£ ounces 0.0135

By calculation this will be found to be equal to 2 j& grains of ^bullion per ton of 2,000 pounds of original earth with a value of some- what less than ten cents, or at the rate of about 13 cents per cubic yard.

If the samples drawn for and used in the assays, were representa- tive of the gravel — and every effort was made to have them such — then the results are not encouraging for profitable extraction of the gold. Under the economic conditions surrounding the deposits, the yield of bullion would not be adequate to cover the expenses of hand- ling and washing or amalgamating, even on the supposition that the bullion can be saved. This latter condition,! believe, as before stated, to be impossible from the form in which the gold occurs in the gravel ; for the second experiment (with the material from Lilly's gulch) seems to indicate that in the process of washing by far the largest part of the gold is carried off, even by the slight force of the current of water in an ordinary prospecting rocker.

To the above may be added a few words on the pyrites — numer- ous samples of which have been brought or sent to the laboratory, on the belief either that the mass of them was gold or that they were gold-bearing to some extent. Of the samples, thirty-eight have been assayed at the request of parties bringing or sending them, and in three only were even traces of gold discovered. The mass of evidence is entirely against the occurrence of auriferous pyrites in Missouri.

INDEX,

PAGE

Activity of lead reverberatory furnances 85

Adaptability of Missouri lead to corrosion 91

Air furnace, dimensions of. 45

Air furnace, method 25

Air furnace, practice at Bond's 55, 56

Air furnace, practice at Buffalo 52, 53

Air furnace, practice at Dade county 49, 50

Air furnace, practice at Davis & Murphy 47

Air furnace, practice at Desloge 59, 60

Air furnace, practice at Eagle 51, 52

Air furnace, practice at Granby 45

Air furnace, practice at Gum Spring 52

Air furnace, practice at Joplin Smelting Company 49-

Air furnace, practice at Linn Creek 56, 57

Air furnace, practice at Lone Elm 48

Air furnace, practice at Pichar & Bro 49

Air furnace, practice at Pioneer 50

Air furnace, practice at St. Joe 58

Air furnace, practice at Star 53, 54

Air furnace, practice at Wyan Spring 54, 55

Air-reaction, method of 26

Akermann, references 131, 13$

Analyses of fluxes, table of. 154

Analyses of charcoal irons, table of. 155

Analyses of leads, table of. 94, 95

Anglesite (Beudant) 19-

Antimony, influence of in lead 97

Antimony, influence of in zinc.. 112

Antimony in galenite 13

Archaean rocks of Shannon county 160

Archimedes limestone.. 8

Arsenic in galenite 13

Arsenic, influence of in zinc 112

Ash Grove, lead furnace j , 62

Ash mineral , , 20

«

Auriferous drift of Missouri 181

Auriferous drift of Missouri, assays of. 182, 183

Auriferous drift of Missouri, value of 182

II INDEX.

PAGE

Azurite (Beudant) 24

Baker, W., color in white lead 93

Bannon & Kramer, color in white lead 93

Barite (Karsten?) 22

Barite, analyses of. 23

Barry county 8

Barren Creek 159

Bartlett white lead, analysis of. 120

Baxter Springs, furnace at 50

Beaver iron ore, analysis of. 134

Ben ton county 8

Benton county, furnace in 57

Bell, Lowthian 131,133, 148

Belgian method of zinc extraction Ill

Big Shawnee Creek 159

Birch Diggings, galenite from * 16

Bismuth in lead, influence of. 97

Bitumen with lead ores 25

Blastfurnaces, at Boullinger Creek 144

Blastfurnaces, at Carondelet Works.. 152

Blast furnaces, at Irondale 146

Blast furnaces, at Iron Mountain..... 145

Blast furnaces, at'Maramec , 127

Blast furnaces at Midland 139

Blast furnaces at Missouri Company's Works < 151

Blast furnaces at Moselle 142

Blast furnaces at Ozark 134

Blast furnaces at Pilot Knob 145

Blast furnaces at Scotia 136

Blast furnaces at South St. Louis Company's Works 150

Blast furnaces at South St. Louis — Results 151

Blast furnaces at Vulcan Works .' , 153

Blast furnaces — currents in 131

Blast furnaces — ideally perfect ; 132

Blast furnace studies ; " Griiner's".. 130

Blast furnace slags, table of analyses of • 154

Blast furnaces, lead, illustrations of. 72, 73, 74, 76

Blast furnaces, lead, methods of. 26, 33

Bleiberg practice * 28, 82, 90

Blende, analyses of 15, 106

Blende from the Central Region 105

Blende from the Southwestern Region 105

Blende, in lead reverberatories 31

Blende, roasting at Borbeck ~ 110

Blende, silver in 106

Blende, varieties of 106

Block mineral- 10

Bloomery at Meramec 134

Bloomery at Meramec, charge at.* 134

Bloomery at Meramec, product of. 134

INDEX. Ill

PAGE

Blue mineral 10

Blue Spring , 160

Bluff diggings, galenite from 17

Boliinger county 9

Bonds' lead furnace 55

Bonds' lead furnace, lead produced at, analysis 56

Bonds' lead furnace, residue from, analysis 56

Boulangerite (Thaulow).. 18

Boullinger Creek Furnace, iron 144

Bournonite (Jameson) 18

Broadhead's Report, references 3, 8, 9, 12, 14, 100, 108, 181

Brookline, lead furnace at 50

Buffalo, lead furnace 52

Buffalo, lead furnace, galenite used at- 17

Buffalo, lead furnace, lead from, analysis 53

Buffalo, lead furnace, residue from, analysis 53

Buratite (Delesse) 109

Cadmium in Granby slag lead- 14

€alamine (Smithson) 23, 106

Calamine, analyses of- „ 24, 107

Calcite (Haidinger)...., * 21

Calcite, analyses of. 21

Calorific effect of reduction of iron oxide 132

Catnden county 8

Carbon, calorific power of , 130

Carbonate^of lead, (see cerussite.)

Carbonic acid, action of on zinc vapor- 110

Carbonic acid and oxide, ratio of in blast furnace 130

Carbonic oxide in blast furnace, Tanner 131

Carinthian lead method. 27.

Carondelet Iron Works 152

Carondelet, zinc establishments at 112

Central Lead Region 8

Cerussite (Haidinger) , 19

Cerussite, analyses of. 20, 21

Cerussite in stalactites , 20

Chalcanthite (V. Kobell) 25

Charcoal, various weights of. 147

Charcoul furnaces, fluxes used at, analyses... 154

Charcoal furnaces, irons made at, analyses 155

Charcoal furnaces, slags from, analyses 154

Charge at Meramec Furnace .'. 128

Charge at Hopewell Oxide Works 123

Charge of the Wetherill Furnace, usual 121

Charge of the Wetherill Furnace, effect of increase of 122

Chauvenet, analyses by 12, 15, 17,20,22, 106, 108, 114

Cheltenham Clays, analyse^ of. 113

Christian county 9

Chunk mineral 10

Church, lead blast furnace methods 36

IV INDEX.

PAGE

Clay, Cheltenham, analyses of. 113

Clay, Oak Hill, analyses of. 114

Clay, Oak Hill, section of deposit 113

Clay, red tough 23

Clay, Stourbridge, analysis of. 113

0 Clay, tallow 23

Cobalt in galenite 15

Cobb, Henry, white lead production of St. Louis , 99

Cobb, Henry, production of St. Louis Shot Tower 100

Coke ashes, composition of. 75

Collin's Furnace , 57

Colorado Keverberatory, results in 88

Cole county 64

Cole county, Galenite 17

Composition of leads, table of. 94, 95

Conoley Furnace 5ft

Consolidated Land Company 164

Consumption of zinc ores in 1875 175

Cooper county 8

Copper deposits of Shannon county A 164

Copper in galenite '. 15

Copper in lead 96

Copper in ores of Shannon county 165, 166

Copper pyrites 15, 166

Corn, S. B., hearths 64

Corn, S. B , reverberatorie? 50s

Cost of slag treatment.. 88, 89

Crawford county, analyses of iron ores from 136, 142

Crawford county, galenite, silver in 12

Cupola Method at Mine La Motte 76,

Currents in blast furnace 131

Current river 159-

Dade county 8

Dade county air-furnace, practice at 49, 50s

Dade county air-furnace, analysis of residue from 50

Dade county air-furnace, analysis of lead from 50

Dade county galenite 16

Dallas county &

Davis & Murphy's air-furnace, practice at .*. 47

Davis & Murphy's slag-furnace 73

Davis & Murphy's slag-furnace, analysis of slag from • 73

Delaware Creek 159=

Dent county, analysis of iron ore from 140

Desloge air-furnace, practice at 59, 60*

Desloge air-furnace, analysis of dross from 61

Desloge air-furnace, analysis of lead from 61

Desloge air-furnace, analysis of residue from A 61

Desloge mine, concentration at 60-

Desloge mine, concentrated ores, analyses 17, 60

Desloge mine, ore from, analysis of. 17

INDEX'.

PAGE

Direct production of white lead substitute 120

Distribution of lead for two years 171

Distribution of materials in Maramec furnace 129, 130

Distribution of materials in Midland furnace 141

Distribution of materials in Moselle furnace 144

Distribution of materials in Scotia furnace 138

Dolomite (Kirwan) 21

Dolomite, analyses of. 22

Dolomite limestone of Shannon county, analysis 163

Douglas county 8

Drift of Missouri, gold in : 181

Dross, analysis of 61

Dross, treatment of 41

Duncan, Gr. A., analysis by 115

Eagle air-furnace, dimensions of.. 51

Eagle air furnace, galenite used at 16

Eagle air-furnace, practice at... 51, 52

Eagle air-furnace, lead from, analysis , 52

Eagle air-furnace, residue from, analysis 52

Eanes & Berry air-furnace 57

Eanes & Berry air-furnace, trials with increased charges 58

East Point galenite, silver in 12

Endemann on bismuth in lead 97

English Flintshire furnaces 27,82,83, 84

English Flintshire furnaces, analyses of residues 30

English method of zinc extraction Ill

Eureka air-furnace 58

Firebrick, Laclede, analysis of. 114

Fire brick, Mitchell, analysis of. 114

Fire brick, Oak Hill, at lead furnaces 53, 55

Flintshire furnaces, English 27,82,83, 84

Flintshire furnace, English, analyses of residue from 30

Flintshire furnace at Frumet 62

Flintshire furnace at Granby 43

Flintshire furnace at Desloge 59, 60

Flintshire furnace compared with other practices 81, 86, 90

Flux used at Maramec furnace 128

Flux used at Midland furnace 140

Flux used at Mine la Motte cupola 77

Flux used at Moselle furnace 143

Flux used at Ozark furnace 135

Flux used at Scotia furnace 137

Fluxes of charcoal furnaces, table of analyses of. 154

Franklin county 9

Franklin county limonite, analysis of 142

Franklin county galenite, silver in ,. 12

Franklinite (Berthierj 109

Frumet Company's furnace 62

Fuel consumption in English Flintshire furnaces 82

Fuel consumption in hearth smelting 86

VI INDEX.

PAGE

Fuel consumption in Maramec furnace.... 128

Fuel consumption in Moselle furnace- 14&

Fuel consumption in ordinary reverberatories 82

Fuel consumption in roasting zinc ores 110

Fuel consumption in slag-smelting 72, 89

Fuel consumption in Scotia furnace 137

Fume from lead furnaces, analyses of. 30, 31

Fume from lead furnaces, collection of 49, 70

Furnace, "Wetherill, for zinc oxide 117

Gage, J. K., reference 109

Galena, (see galenite.)

Galenite (V. Kobell) « 9

Galenite, foreign metals in 12, 16, 17

Galenite in zinc oxide furnaces 120

Garvens, O. E., analysis by 21

General metallurgy of zinc 109

Genth, references 10, 107, 181

Geocronite (Svanberg) 18

Geographical distribution of lead ores 8

Gold in drift of Missouri 182

Goslarite (Haidinger).. 24, 109

Grabill, L. R., analyses by... 107, 114

Granby, air-furnace, practice at 45

Granby carbonate ore, analysis of. 20

Granby calamine, analysis of 107

Granby cerussite, analysis of. 21

Granby, Flintshire, practice at... .* 43

Granby fume, analysis of 30

Granby galenite, analyses of. 16

Granby hearth practice 63

Granby leads, analyses 45, 60, 73

Granby residues, analyses of. 44, 46, 47

Granby residues, treatment of. 72

Granby slags, composition of. 72

Granby slag-lead, analysis of 73

Grass Root Furnace- i 57

Greason, J. D., analyses by 15, 23, 166

Greene county 8

Gruner's Blast Furnace Studies, reference 130

Gum Spring Furnace... .: 52,

Gypsum 24

Hampe on lead kernels 98

Hampe's analyses of white lead products 99

Hancock iron ore, analysis of. l-*4

Handlin furnace * 57

Handlin furnace, analysis of residue from 57

Hare, A. W., assistant in laboratory 4

Hearth, American water back 36

Hearth, dimensions 37

Hearth, charges of. 81

INDEX. VII

PAGE

Hearth compared with reverberatories 87

Hearth, composition of residues from 87

Hearth, fuel, consumption in ., 81

Hearth method at Bleiberg 38

Hearth method at Granby 63

Hearth method at Hopewell 65, 60

Hearth method at Joplin Smelting Company 64

Hearth method at Lone Elm « 64

Hearth method at Mine la Motte 68, 69

Hearth method at O'Brien 64, 65

Hearth method at Perry , 65

Hearth method at Valle 67

Hearth Residues, analyses 64, 65, 66, 67, 69

Hearth Residue, Plattner's Analysis of. 38

Heat requirements of Maramec furnace 133

Heat requirements of Midland furnace 142

Heat requirements of Moselle furnace 144

Heat requirements of Scotia furnace 139

Herrerite (Del Rio) 107

Hesselmeyer. George 112

Hickory county ,.... 8

Holman diggins, silver in galenite from 12

Hopewell hearth, practice at 65

Hopewell galenite, foreign metals in 17

Hopewell lead, analysis of 66

Hopewell residue, analysis of. 65

Hopewell slag-furnace, analysis of slag from 74

Hopewell zinc oxide furnaces 122

Hopewell zinc oxide furnaces, analyses of products 122, 124

Hopewell zinc oxide furnaces, production of. 124

Hydrozincite (Kenngott) 108

Illustrations of Lead Smelting in Missouri 42

Importations of lead at St. Louis 171

Iron from Maramec furnace, analysis of. 128

Iron from Midland furnace, analysis of. 140

Iron from Moselle furnace, analysis of 143

Iron from Ozark furnace, analysis of. 135

Iron from Scotia furnace, analysis of 137

Irons from charcoal furnaces, table of analyses of 155

Iron as a desulphurant 32

Iron in galenite 15

Iron oxide, reduction of. 131

Iron oxide in zinc retorts 112

Irondale blast furnace 146

Iron Mountain blast furnaces 145

Iron ores, analyses of 127, 134, 136, 140, 142

Iron ores, leichtfliissig 148

Iron ores in Shannon county 167

Iron ores, strengfliissig 148

Jack's Fork of Current river.... .. 159

vim INDEX.

PAGE

Jamesonite (Haidinger) , 18

Jasper county 8

Jasper county galenite, foreign metals in 16

Jasper county galenite, silver in 12

Jefferson county 9

Jefferson county galenite, silver in 12

Joplin Mining and Smelting Company's furnaces 49

Kaolinite, formula of 113

Kaolinite from Cornwall, analysis of 114

Keokuk limestone... 8

Kerl's Metallurgy, references 27, 32, 34, 110

Kernels from while lead, corrosions, analysis. of Lantenthal 99

Kernels from white lead, corrosions, analysis of Mechernich 99

Kernels from white lead, corrosions, analysis of Missouri 98

Kernels from white lead, corrosions, analysis of Silesian 99

Keystone zinc oxide, analysis of 120

Krummofen 41, 71

Labor at English Flintshire furnaces 83

Labor at Hearths 86

Labor at ordinary reverberatory furnaces 81, 83

Labor at slag furnaces 72

Laclede county 9

Laclede county galenite, silver in : 12

Lead, analysis of, from Bond's furnace 56

from Buffalo furnace 53

from Dade county furnace 50

from Desloge furnace •. 61

from Eagle furnace 52

from Granby furnace 45, 63, 72

from Hopcwell furnace ~66, 74

from Linn Creek furnace 57

from Lone Elm furnace 49, 64

from Mine la Motte 69, 77

from Perry furnace 66

from Pioneer furnace < 51

from St. Joe furnace 59

from Star furnace 54

from VallS furnaces 67,68, 75

Lead analyses, table of 94, 95

Lead, antimony in 97

Lead, copper in... 96

Lead, distribution of. 171

Lead, importations at St. Louis 171

Lead, Missouri, adaptability of, for corrosion.. 91

Lead production for 1875 173

Lead, prices of 1"4

Lead, purification of. 39

Lead Region, the Central 8

Lead Region, the Southern 9

Lead Region, the Southeastern 9

INDEX. IX

PAGE

Lead Region, the Southwestern 8

Lead ores, carbonate 19

Lead ores, geographical distribution of. 8

Lead ores, oxidized 9, 19

Lead ores, sulphuretted 9, 18

Lead ores, Shannon county 167

Lead, St. Louis receipts of- 172

Lead, Suailbeach 100

Lead, «W. B." 92

Leonhard and Schmidt, references 8, 9

Lilly's gulch, gravel from 182

Limestone, Archimedes 8

Limestone, Keokuk 8

Limestone, second magnesian 9

Limestone, third magnesian 9, 163

Limestone, third magnesian, analysis of. 163

Limonite 24, 166

Lirnonite from Franklin county, analysis of. 142

Limonite from Hancock bank, analysis of. 134

Limonite used at Irondale blast furnace 146

Linn creek furnace 56

Linn creek furnace, lead from, analysis 57

Linn creek furnace, residue from, analysis 57

Luton, assays of galena by.. 12

Lone Elm furnace- 48

Lone Elm furnace, collection at..... 49

Lone Elm hearths 64

Lone Elm leads, analyses of..... « 49, 64

Lone Elm residue, analysis of. 48

Macon county, gold in drift of. 182

Madison county 8

Madison county galenite, silver in 12

Malachite (Wall) 24, 165

Mammoth Spring 160

Maramec furnace 128

Maramec furnace, bloomery at 134

Maramec furnace, charge 128

Maramec furnace, distribution of materials 129

Maramec furnace, flux 128

Maramec furnace, fuel consumption 128

Maramec furnace, heat requirements of. 142

Maramec furnace, products, analyses of. 128, 129

Maries county 8

Maries county galenite, silver in... 12

Marionite (Elderhorst) 109

Marmaduke furnace 57

Martindale Zinc Works 115, 117

Matte, concentrated at Mine la Motte 78

GR— 13

INDEX.

Matte first, at Mine la Motte

Matte, roasted at Mine la Motte 77

McDonald county g

Melaconite (Dana) 166

Method of desulphurization by iron 32

Method by air-reaction 26

Methods, blast furnace for lead , 33

Midland furnace 139

Midland furnace, distribution of materials in 141

Midland furnace, flux and ore, analyses 140

Midland furnace, heat requirements of. 142

Midland furnace, products of, analyses 140

Miller county 8, 12

Mine la Motte 68

Mine la Motte, cupola methods at 76

Mine la Motte, hearth method at 68

Mine la Motte, lead produced at, analyses 69, 76

Mine la Motte, matte treatment at 77

Mine la Motte, hearth residue, analyses 68

Mine la Motte, Smithonite from, analysis 108

Mine water, analyses of. 25

Minger, W. 0., analyses by 17, 23, 77

Missouri Company's Zinc Works 115, 117

Missouri Furnace Company... 151

Moniteau county 8

Morgan county 8

Morgan county galenite, silver in 12

Moselle furnace 142

Moselle furnace, distribution of materials in 144

Moselle furnace, flux and ores, analyses 142, 143

Moselle furnace, heat requirements of. 142

Moselle furnace, products of, analyses 143

Mt. Lincoln, Colorado, reverberatory 88

Murray's Gulch 182

Neosho Manufacturing Company's Hearth 64

Newton county 8

Newton county galenite, foreign metals in 16

Newton county galenite, silver in 12

Newton county, (see also Granby.)

Nickel in galenite 15

Nickel in lead 92

Nickel matte, production of. ; 76

Nickel mattes, analyses of. 77, 78

Oak Hill fire clay 113

Oak Hill fire clay, analyses of. 114

Oak Hill fireclay, section of deposit 113

Oak Hill fire bricks 53, 55, 114

O'Brien's hearth 64

O'Brien's hearth galenite, foreign metals in 17

O'Brien's hearth, residue from, analysis 65

INDEX. XI

PAGE

Ohmann-Dumesnil, A. H., analyses by 24, 165

Old Scott furnace.. 57

Oronogo galenite, silver in 12

Oronogo, hearth at . 64

Oronogo, Mine water from, analyses.. 25

Ores, copper in Shannon county 165, 166

Ores, oxidized 9, 19

Ores, sulphuretted.. 9, 18

Ores, iron, (see different furnaces.)

Osage county 8

Osage river, iron ore?- 144

Osterode lead works 97

Otterville furnace 57

Oxide of iron, reduction of. 131, 132

Oxidized ores of lead 9, 19

Oxygen ratios of iron slags ...129, 135, 138, 141,144, 154

Oxygen ratios of lead slags.... 35, 73, 74, 75, 78

Ozark furnace 134

Ozark furnace, flux used at, analysis 135

Ozark furnace, iron produced at, analysis 135

Ozark furnace, ores used at, analyses 134

Ozark furnace, slag from 135

Pack, James A., analyses by 24, 114, 165

Pack, John P., analyses by 115, 116

Percy's Metallurgy of lead, references 28, 30, 37, 82, 92, 100, 115

Perry's hearths 66

Perry's hearths, foreign metals in galenite from.. 17, 18

Perry's hearths, lead from, analysis 66

Perry's hearths, residue from, analysis.. 66

Perry's mines, silver in galeuite from 12

Peters, E. D., results with reverberatory in Colorado 88

Pettis county 8

Phelps county 8

Phelps county galenite, silver in 12

Phosphate of lead 19

Pichar Bros, air-furnace 49

Pilot Knob furnace 145

Pioiit.tr furnace , «. 50

Pioneer furnace, lead from, analysis 51

Pioneer furnace, residue from, analysis 51

Plagionite (G. Rose) 18

Porphyry of Shannon county 161

Porphyry of Shannon county, analysis of. 161

Porphyry of Shannon county, bedding of. 162

Potosi Mining Company, silver in galenite from 12

Pratt's Mill furnace.. 57

Pressing 29

Prices of lead 174

Prices of zinc «... 177

Production of lead and ores in 1875.... .. 173

XII INDEX.

PAGE

Production of zinc by States 176

Production of zinc ores in 1875 175

Puddling mill, Vulcan Works 153

Pulaski county galenite, silver in 12

Purification of lead 39

Pyrites, iron 15

Pyromorphite(Hausmann) 19

Quartz as a gangue of lead ores 23

Quartz in reverberating furnace 32, 88

Quartzite associated with lead ores 23

Quartzite of Shannon county, analysis of. 163

Quartzite of Shannon county, genesis of. 163

Kail mill, Vulcan Works 153

Katio of carbonic acid and oxide in blast furnace v 130

Eatio, oxygen and slags 35, 73, 74, 75, 78, 129, 135, 138, HI, 144, 154

Kaymond, R, W., reference 36

Receipts of lead at St. Louis 172

Receivers for zinc distillation, dimensions of. 112

Red lead, St. Louis, foreign metals in 100

Red lead, Snailbeach, foreign metals in 100

Reduction of oxide of iron 131

Residue, analysis of, from Bond's furnace 56

Residue, analysis of, from Buffalo furnace 53

Residue, analysis of, from Dade county furnace 50

Residue, analysis of, from Desloge furnace 61

Residue, analysis of, from Eagle furnace.! 52

Residue, analysis of, from Granby furnaces 44, 47

Residue, analysis of, from Handlin furnace 57

Residue, analysis of, from Hopewell hearth 65

Residue, analysis of, from Hopewell oxide works 123

Residue, analysis of, from Linn Creek furnace 57

Residue, analysis of, from Lone Elm furnace 48

Residue, analysis of, from Mine la Motte hearth 69

Residue, analysis of, from O'Brien's hearth 65

Residue, analysis of, from Perry hearths 66

Residue, analysis of, from Pioneer furnace 51

Residue, analysis of, from St. Joe furnaces- . 59

Residue, analysis of, from Star furnace 53

Residue, analysis of, from Valle hearths : 67

Residue, analysis of, from Wyan Springs furnace 54

Residue from Zinc oxide works, analysis of 121

Results at South St. Louis furnaces 151

Retorts for zinc furnaces, dimensions of. Ill

Reverberatory furnaces 26, 27

Reverberatory furnaces, weight of charges in - 82

Reverberatory furnaces, fuel consumption in 82

Reverberatory furnaces, labor at 83

Reverberatory furnaces, yield of lead ore in 85

Reverberatory furnaces, activity of different forms of. 85

Reverberatory furnaces and hearths compared 87

INDEX. XIII

PAGE

Keverberatory practice, illustration of 42

Reverberatory results in Colorado... 88

Keverberatory furnace, (see also Air-furnace and Flintshire furnace.)

Richardson's shaft, foreign metals in galenite from 16

Riggin's and Chapman's hearths 64

Revols Metallurgy de Plomb, references 34, 82

Round Spring.. 160

Saline county 8

Saline Valley Furnace 62

Sarver & Co.'s furnace 50

Schmidt, Dr. Adolph, notes and references 4, 8, 58, 113, 134, 137, 144, 145, 146

Schwietzer, Dr. Paul, references 96, 101

Scotia furnace 136

Scotia furnace, distribution of materials in 139

Scotia furnace, flux and ores used at 136, 137

Scotia furnace, heat requirements of. 139

Scotia furnace products, analyses of 137, 138

Second magnesian limestone.. 9

Seedtick diggins galenite, foreign metals in * 17

Shannon county 159

Shannon county, Archaen rocks of 160

Shannon county, copper deposits 164

Shannon county, copper ores 165, 166

Shannon county, iron ores 167

Shannon county, lead in 167

Shannon county, Silurian rocks of. 163

Shot Tower of St. Louis, produce of. 100

Siderite (Haidinger) 22

Silesian method of zinc extractor Ill

Silurian rocks of Shannon county 163

Sinking creek « 159

Skimmings, lead, (see dross.)

Skimmings, zinc, analysis of. 116

Slags, iron blastfurnace, analyses of 154

Slags, iron blast furnace, oxygen ratios of 129 135,138, 141,144, 154

Slags, lead blast furnace, oxygen ratios 35, 73, 74, 75, 78

Slag leads, analyses of. 73, 75, 77

Slag treatment in Missouri 70

Slag treatment, cost of. 72

Smithsonite (Beudant) 107

Smithsonite: analyses of« 24, 108

Smithsonite, varieties of 107

Snailbeach lead 100

Southern lead region 9

Southeastern lead region 9

Southeastern lead region, reverberatories 58

Southeastern lead region, hearths 65

Southwestern lead region 9

Southwestern lead region, reverberatories 43

Southwestern lead region, hearths * 63

XIV INDEX.

PAGE

South St. Louis blast furnaces 150

Spelter, analyses of. 115

Spelter, production of, 1875 175

Sphalerite, (Glocker,) see Blende.

St. Clair county 8

St. Francois county 9

St James iron ore, analysis of. 134

St. Joe furnaces 58

St. Joe furnace, lead from, analysis '. 59

St. Joe furnaces, residue from, analysis 59

St. Joe galenite, foreign metals in 17

St. Louis Shot Tower 100

Ste. Genevieve county 9

Star furnace 53

Star furnace lead, analysis of. 54

Star furnace residue, analysis of. 53

Stone county 9

Stourbridge clay, analysis of. 115

Sulpherretted lead ores 9, 18

Swallow's report, references 3, 9, 12

Swindle digging galenite, silver in 12

Taney county 9, 108

Texas county 9

Temple diggings galenite, silver in 12

Third Magnesian limestone 9

Third magnesian limestone, analysis of ; 1C3

Thurman Mining and Smelting Company's hearth 64

Time on element in blast furnace reactions 148

Trent diggings galenite, silver in 12

Tunner, reference 131

Valid lM-arths.... 07

Valid hearths galenite, foreign metals in 17

Valid hearths leads, analysis of 67, G8

Valid hearths residue, analysis of. 67

Valid mines Smithsonite, analysis of. 108

Valid slag furnace 74

Valle slag furnace, analysis of slag from 74

Valle slag lead, analysis of. 74

Variation of silver in same pig lead 96

Velocity of current at Mammoth Spring 1GO

Velocity of currents in blast furnaces 131

Village diggings galenite, silver in.. 12

Volatilization, loss by in lead smelting 31, 89

Volume of discharge at Blue Spring ICO

Volume of discharge at Mammoth Spring 165

Volumes of Missouri Blast Furnaces , 149

Vulcan Iron Works 153

Washington county, Irondale furnace 146

Water, action of zinc vapor 110

Water from lead mines, analyses of 25

INDEX. XV

PAGE

Watersystem of Shannon county 159

W. B. Lead : 92

Wear of Zinc retorts 112

Webster county 9

Weight of charges in air-furnaces 82

Weight of charges in hearths 86

Weight of charges in zinc oxide furnaces 123

Weight of charges for zinc retorts Ill

Weights of charcoal, various 147

Wetherill furnace 117

Wetherill furnace, usual thickness of charge in 120

Wetherill furnace, influence of heavy charging 120

White lead, causes of color in 93

White lead from Lantenthal lead 99

White lead from Mechernich lead 99

White lead from Missouri lead 98

White lead from Silesian lead- 99

White lead in St. Louis, statistics of. 99

White lead substitute, directly from ore 120, 121

Willemite (Levy) .. 109

Winters, C. K, analysis by . 24

Wool mineral, analysis of. 20

Wright county 9

Wyan Springs furnace 54

Wyan Springs furnace lead, analysis of. 55

Wyan Springs furnace residue, analysis of.. 54

Yield of lead ores in reverberatory furnace 83

Yield of lead ores in hearths 87

Yield of copper ores shipped from Shannon county 166

Yield of Zinc ores 117

Zinc, analyses of... 117

Zinc carbonate, (see Smithsonite.)

Zinc hydrous carbonate, (see hydrozincite )

Zincite (Haidinger) 109

Zinc in galenite 13

Zinckenite (G. Rose) 18

Zinc, general metallurgy of '. 109

Zinc establishments at Carondelet 117

Zinc ores, consumption of in 1875... 175

Zinc ores, loss in calcination 116

Zinc ores, ratio of different kinds produced 109

Zinc ores, production in 1S75 175

Zinc oxide, Bartletts, analysis of. 120

Zinc oxide from Hopewe-11 furnaces, analyses , 124

Zinc oxide furnaces at Hopewell 122

Zinc oxide, history of manufacture .*... 117

Zinc oxide, Keystone, analysis of. 120

Zinc oxide, production at Hopewell 124

Zinc oxide, uses of 124

Zinc, prices of. 177

XIV INDEX.

PAGE

South St. Louis blast furnaces 150

Spelter, analyses of. 115

Spelter, production of, 1875 175

Sphalerite, (Glocker,) see Blende.

St. Clair county.. 8

St. Francois county 9

St James iron ore, analysis of. 134

St. Joe furnaces 58

St. Joe furnace, lead from, analysis '. 59

St. Joe furnaces, residue from, analysis 59

St. Joe galenite, foreign metals in 17

St. Louis Shot Tower 100

Ste. Genevieve county 9

Star furnace 53

Star furnace lead, analysis of. 54

Star furnace residue, analysis of. » 53

Stone county 9

Stourbridge clay, analysis of. 115

Sulpherretted lead ores 9, 18

Swallow's report, references 3, 9, 12

Swindle digging galenite, silver in 12

Taney county 9, 108

Texas county 9

Temple diggings galenite, silver in 12

Third Magnesian limestone 9

Third magnesian limestone, analysis of ; 163

Thurman Mining and Smelting Company's hearth 64

Time on element in blast furnace reactions 148

Trent diggings galenite, silver in 12

Tunner, reference 131

VallS hearths 07

Valle hearths galenite, foreign metals In 17

ValJ6 hearths leads, analysis of. 67, 68

Vall6 hearths residue, analysis of. 67

Valle mines Smithsonite, analysis of. 108

ValI6 slag furnace 74

Valle slag furnace, analysis of slag from 74

Valle slag lead, analysis of. 74

Variation of silver in same pig lead 96

Velocity of current at Mammoth Spring 160

Velocity of currents in blast furnaces 131

Village diggings galenite, silver in.. 12

Volatilization, loss by in lead smelting 31, 89

Volume of discharge at Blue Spring 160

Volume of discharge at Mammoth Spring 165

Volumes of Missouri Blast Furnaces , 149

Vulcan Iron Works 153

Washington county, Irondale furnace 146

Water, action of zinc vapor 110

Water from lead mines, analyses of 25

INDEX. XV

PAGE

Water system of Shannon county 159

W. B. Lead 1 92

Wear of Zinc retorts 112

Webster county 9

Weight of charges in air-furnaces 82

Weight of charges in hearths 86

Weight of charges in zinc oxide furnaces 123

Weight of charges for zinc retorts Ill

Weights of charcoal, various 147

Wetherill furnace 117

Wetherill furnace, usual thickness of charge in 120

Wetherill furnace, influence of heavy charging 120

W^hite lead, causes of color in 93

White lead from Lantenthal lead 99

White lead from Mechernich lead 99

White lead from Missouri lead 98

White lead from Silesian lead 99

White lead in St. Louis, statistics of. 99

White lead substitute, directly from ore 120, 121

Willemite (Levy) 109

Winters, C. K., analysis by 24

Wool mineral, analysis of. 20

Wright county 9

Wyan Springs furnace 54

Wyan Springs furnace lead, analysis of. 55

Wyan Springs furnace residue, analysis of.., 54

Yield of lead ores in reverberatory furnace 83

Yield of lead ores in hearths 87

Yield of copper ores shipped from Shannon county 166

Yield of Zinc ores 117

Zinc, analyses of... 117

Zinc carbonate, (see Smithsonite.)

Zinc hydrous carbonate, (see hydrozincite )

Zincite (Haidinger) 109

Zinc in galenite 13

Zinckenite (G-. Rose) 18

Zinc, general metallurgy of 1 109

Zinc establishments at Carondelet 117

Zinc ores, consumption of in 1875... 175

Zinc ores, loss in calcination 116

Zinc ores, ratio of different kinds produced 109

Zinc ores, production in 1875 175

Zinc oxide, Bartletts, analysis of. 120

Zinc oxide from Hopewell furnaces, analyses , 124

Zinc oxide furnaces at Hopewell 122

Zinc oxide, history of manufacture .*... 117

Zinc oxide, Keystone, analysis of 120

Zinc oxide, production at Hopewell 124

Zinc oxide, uses of 124

Zinc, prices of. 177

XVI INDEX.

PAGK

Zinc, production of, by States 176

Zinc receivers, dimensions of Ill

Zinc retorts, dimensions of. Ill

Zinc scoria from retorts, analysis of. 117

Zinc silicate, (see Willemite.)

Zinc silicate, hydrous, (see calamine.)

Zinc skimmings, analysis of 116

Zinc vapor and carbonic acid 115

Zinc vapor and water 115

Zinc white, (see zinc oxide.)

Page 14, line 20, for " analysis " read *• analyses " Page 19, line 23, for " lust " read " lustre." Page 22, line 6, omit parenthesis after "limonite." Page 26, line 8, for "being" read "are." Page 41, line 8, for " Krumofen " read " Krummofen." Page 67, line 6, after "'furnace" insert tl capacity." Page 68, line 9, for "Rogers' " read "Rozier." Page 91, line 2, for "three fining" read " the refining." Page 93, line 8, after " J " insert " attributes it."

The last paragraph on page 93, and the tables on pages 94 and 95 should precede the last paragraph on page 92.

Page 109, line 23, lor " Williamite " read " Willemite:'1

Page 112, line 34, for " speltre" read "spelter."

Page 152, line 22, after " effected " insert " by wire drawing."

Page 160, line 36, after " giving " insert " 660."

Page 160, line 38, for "Archean " read " Archaean."

Page 165, line 35, for " Gavens " read " Garvens."

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