Patent ID: 8545593

Claim:
A method for producing liquid ferroalloy by direct processing of manganese and chromium bearing compounds, comprising the steps of: (a) mixing: i. materials selected from the group consisting of iron sands, metallic oxides, manganese-iron ore concentrates and/or chromium-iron ore concentrates and silica sands, at least one of which contains either manganese or chromium; ii. carbonaceous reductant; iii. fluxing agent; and iv. a binder to form a mixture; (b) forming agglomerates from said mixture; (c) preheating at least a portion of said agglomerates in a rotary kiln heater to a temperature of 500 to 1200 C.; (d) introducing said preheated agglomerates to a melting furnace; (e) maintaining an operating pressure within the melting furnace from neutral to slightly positive; (f) maintaining a reducing atmosphere within the melting furnace; (g) melting the feed materials at a temperature of from 1500 to 1760 C and forming a slag thereon containing oxides of manganese and chromium; (h) removing the slag; (i) quenching the molten slag to solidify the slag; (j) grinding the solid slag; (k) separation of MnO and Cr 2 O 5 from the slag; (l) recovery of MnO and Cr 2 O 5 ; (m) tapping the hot metal as hot liquid ferroalloy; (n) forming off-gases in the melting furnace, cleaning and cooling the off-gases, and utilizing the cleaned off-gases as combustion fuel to drive a turbine and to generate electricity; and (o) producing off-gases in the turbine, recovering the off-gases from the turbine and recovering the sensible heat contained therein as steam in a waste heat recovery boiler system.