PROGRESS IN ELECTRO-METALLURGY—KERSHAW. 993 
With regard to the use of ferroalloys generally, ferrosilicon is 
employed as a deoxydizing agent, while the other alloys are em- 
ployed for introducing the rarer metals into the steel, it having been 
found that a more homogeneous product is obtained when the metal 
is introduced into the molten steel in the form of an alloy than when 
it is introduced in the pure state. All the chrome-steel used for 
armour-plate manufacture is now made with the aid of ferrochrome. 
Iron and steel—The methods of producing iron and steel in the 
electric furnace have been developed chiefly by French electrometal- 
lurgists, a large number of works in France having been rendered 
idle by the collapse of the boom in the calcium-carbide industry in 
1899-1900, and new Resuiaueee 
applications being re- paiecomiocstombosat= 
quired for the water- ey 
power and_ electric- 
furnace plant thus 
made available. The 
earhest trials of the 
electric furnace for 
iron and steel produc- 
tion date from 1899, 
and since that year A earl | poe Ed 2 tat felts 
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experimental work Ee eh i 
has been carried on 
continuously. Dur- tan 
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ing the last three 
years the new meth- 
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ods have attracted the 
attention of _ steel 
makers, and it is NOW ape oeees LA ea 
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generally recognized Ea eA Bee Ze 
that certain of the Fic. 2.—Vertical section of a Giroud electric furnace 
methods and processes for crucibles individually heated. 
have attained a permanent footing in the iron and steel industry. 
The Heroult and Kjellin methods of steel refining by aid of electric 
heat have shown the most striking development, and a large number 
of works in Europe and America are using these methods with satis- 
.factory results. 
The Heroult steel-refining furnace is of the crucible type, and the 
heating is initially effected by means of the electric arc, which forms 
between the surface of the slagging materials covering the metal and 
the two massive carbon electrodes which are suspended above it. The 
slag when molten is used for resistance heating, the carbons being 
lowered until they touch it. The impurities of the iron are removed 
by renewing the slag from time to time. The refining operation thus. 
becomes a “ washing out ” of the impurities of the iron, by treatment 
