Metallurgy Of Cast Iron

PROPERTIES OF ORES USED IN MAKING CAST IRON. 2? ]
Manganese Is found in nearly all iron ores. It |
readily alloys with iron, and all the manganese con- \
tained in pig iron is obtained from the ores. Manga- 'J »
nese occurs in ores in the form of manganese dioxide
and manganese oxide. Some ores are so high in 4
manganese tnat they are called manganiferous ores,
and of late years their reduction has been achieved in ,\
blast furnaces about as readily as iron ore is reduced,
although at one time it was thought impossible to ,,
obtain high manganese pig from a blast furnace. j<
Ferro=manganese is obtained by smelting manganiferous ores in a blast furnace, and is placed on the market as a commercial product containing from 40
per cent to 90 per cent of manganese. The standard j;
contains from 79 to 81 per cent. _ j .
Spiegeleisen or " Spiegel" is a product of manganif- I
erous ores, but lower in manganese than ferro-manga- !
nese. It ranges from 7 per cent to 40 per cent of \t
metallic manganese. The standard contains from 19 (J
to 21 per cent. In this form it generally presents a ', '
silvery white fracture with a crystalline structure. By ., * -
some this metal is called "looking-glass iron," the /^
English translation of Spiegeleisen. Spiegeleisen is '*$',
readily produced, whenever sufficient manganese is \f^
present in the ore. Both these manganese metals are jf|V
chiefly used in the manufacture of steel in its many v|r
and various grades. if j
Phosphorus exists in most iron ores. Almost all the l| <*
<> r tt
phosphorus contained in the ore, fuel and flux is ^fj
reduced and absorbed by the metallic iron when [ I)
smelting or remelting it. Low phosphorus ores are ?;
generally of greater value than high phosphorus ores. f|f;
For Bessemer iron, in which phosphorus must not |v>