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US 5,387,274 AGranted
Process for the production of iron carbide
AssigneeC.V.G. Siderurgica Del Orinoco, C.A.
InventorsOscar G. Dam G., Henry R. Bueno C.
Life of this patent
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Abstract
A process for converting iron oxide to iron carbide at low pressure includes providing a reforming-reduction-carburizing reactor wherein a feed gas is reformed by contact with the iron oxide materials, the iron oxide material is reduced and thereafter contacted with a carburizing agent so as to carry out the conversion of iron oxide to iron carbide in the reactor.
Claims26
A process for the conversion of iron oxides to iron carbide at low pressure, comprising the steps of:
- (a) providing a reforming-reduction-carburizing reactor operating at a pressure of between about 1.15 to about 1.45 bars and having a bed of partially metallized iron oxide material, a bed of direct reduced iron and a bed of iron carbide within said reactor;
- (b) feeding metal oxide material containing iron to said reactor;
- (c) providing a feed gas having a methane content of at least about 8.5% by volume;
- (d) heating said feed gas to a temperature of between about 650.degree. C. to about 850.degree. C. to form a reheated feed gas and a combustion flue gas;
- (e) mixing air at a temperature of between about 650.degree. C. to about 850.degree. C. with said heated feed gas in a mixing chamber to form a mixture of air and feed gas;
- (f) partially combusting said mixture of air and feed gas to a temperature greater than about 850.degree. C. to form a partially combusted gas mixture wherein said partially combusted gas mixture has a degree of oxidation of between about 0.27 to about 0.32 and a reducing power of between about 2 to about 3;
- (g) feeding said partially combusted gas mixture to said direct reduced iron in said reactor so as to form a reformed reducing gas having an oxidation degree of between about 0.05 to about 0.09;
- (h) contacting said iron oxide material with said reformed reducing gas so as to form direct reduced iron;
- (i) contacting said direct reduced iron with a carburizing agent in said reactor at a temperature of between about 550.degree. C. to about 750.degree. C. so as to form iron carbide having between about 40% wt to about 5.5% wt carbon and at least about 80% wt iron wherein a reactor top gas is formed;
- (j) recycling reactor top gas from said reactor so as to provide a feed gas having a methane content Of at least about 8.5% by volume;
- and
- (k) repeating steps (a), (b) and (d) through (j).
9 more elements
Dependencies are inferred from the claim text.