SYSTEM AND METHOD FOR REDUCING IRON OXIDE TO METALLIC IRON USING COKE OVEN GAS AND OXYGEN STEELMAKING FURNACE GAS

摘要

A process for the direct reduction of iron ore when the external source of reductants is one or both of coke oven gas (COG) and basic oxygen furnace gas (BOFG). Carbon dioxide is removed from a mixture of shaft: furnace off gas, obtained from a conventional direct reduction shaft: furnace, and BOFG. This C02 lean gas is mixed with clean COG, humidified, and heated in an indirect heater. Oxygen is injected into the heated reducing gas. This hot reducing gas flows to the direct reduction shaft furnace for use. The spent hot reducing gas exits the direct reduction shaft furnace as shaft furnace off gas, produces steam in a waste heat boiler, cleaned in a cooler scrubber, compressed, and recycled to join fresh BOFG. A portion of the shaft furnace off gas is sent to the heater burners.