Direct processing of metallic ore concentrates into ferroalloys
AssigneeCardero Resource Corporation
InventorGlenn E. Hoffman
Life of this patent
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Abstract
A method for producing liquid ferroalloy by direct processing of manganese and chromium bearing iron compounds, by the steps: of mixing carbonaceous reductant, fluxing agent, and a binder with materials such as iron sands, metallic oxides, manganese-iron ore concentrates and/or chromium-iron ore concentrates and silica sands, to form a mixture; forming agglomerates from the mixture; feeding the agglomerates to a melting furnace with other materials; melting the feed materials at a temperature of from 1500 to 1760° C. and forming a slag and hot metal; removing the slag; tapping the hot metal as liquid ferroalloy, and utilizing the off-gases from the melting furnace as combustion fuel to drive a turbine and to generate electricity.
Claims16
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 Cr2O5 from the slag;
- (l) recovery of MnO and Cr2O5;
- (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.
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 a positive operating pressure within the melting furnace;
- (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 Cr2O5 from the slag;
- (l) recovery of MnO and Cr2O5;
- (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.
Dependencies are inferred from the claim text.