DIRECT REDUCTION PROCESS WITH IMPROVED PRODUCT QUALITY AND PROCESS GAS EFFICIENCY Russian patent published in 2018 - IPC C21B13/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to production of direct reduction iron DRI. Method comprises direct reduction of iron from iron oxide particles in a reduction reactor at 750 °C with a reducing gas containing H₂, CO, CO₂, H₂O and methane. Top gas effluent from the reduction reaction after cooling/scrubbing is split. Resulting first top gas portion with a first hydrocarbon-containing make-up gas passes through a catalytic reformer yielding an improved hot reducing gas first effluent. Second top gas portion passes through a CO₂ removal unit and then with the second hydrocarbon-containing make-up gas passes through a heater yielding a hot CO₂-lean recycle reducing gas second effluent. First and second effluents are fed to the reducing zone of the reduction reactor as the reducing gas reactant. Flow rate of at least the second of the two make-up gases is regulated to control the carbon content of the DRI produced.

EFFECT: invention provides energy efficiency and reduced capital and operating costs.

25 cl, 5 dwg