588 
MAKGATfESE DEPOSITS OF I^^)IA : ECONOMICS. [P ART III : 
and interest on rapital laid out. What is left after making this 
deduction is the approximate profit per ton of ferro- manganese manu- 
factured. I have no information as to costs of plant, smelting, etc., 
and consequently cannot give a figure for this deduction. The market 
price for pig iron in England in the early part of 1908 has ranged from 
48 to 50 shillings ; this has of course to cover the manufacturer's 
total costs of materials and smelting, interest on capital, etc., and 
his profit, though the latter may have been small at this time. 
Since ferro- manganese is smelted in a similar way to pig iron, even 
though the wear of the furnace is greater, and men who understand the 
manufacture of ferro mav be able to command higher salaries, it is not 
probable that the deduction that has to be made from the figure of 
Rs. 81 given above is greater than Rs. 30, and not at all improbable 
that it is considerably less. Hence it mil be seen that even though the 
figures I have given are very rough, yet there seems to be room for a 
handsome profit in manufacturing ferro-manganese in India ; and it 
certainly looks as if it should be worth some one's while to go seriously 
into the question. 
These two alloys, spiegeleisen and ferro-manganese, are used chiefly 
in the Bessemer and open-hearth processes for 
Use of spiegeleisen and j^aking both acid and basic mild steel. In all 
ferro-manganese. <^ 
cases they are added at the end of the process. 
The alloy may either be charged direct into the furnace, or it may be put 
in the launder through which the molten metal rims on being tapped from 
the furnace into the casting ladle, or it may be put into the casting ladle 
itself. On account of the requisite time (5-12 minutes) and temperature 
conditions being obtained and a more thorough mixing being efTected, 
with a consequent more uniform product, the first method is preferred 
by some, i The reason for the addition of the alloy is twofold : — 
(1) To supply the carbon requisite to convert the metal, which has 
become decarburized in the furnace, into steel. 
(2) To remove the oxygen taken up by the bath of molten metal 
with the formation of oxide of iron. 
All the manganese concerned in this process of breaking up the iron 
, oxide passes into the slag as manganous oxide. 
Quantity of manganese ' , 
required in the maniifac- But, as Will be Seen from page 592, a certam pro- 
ture of steel. portion of manganese in the finished steel is 
I Iron and Steel Mag.. IX, May 190i5, pp. 474—5. 
