Process for coal based ironmaking by compensating reducing gas in CDQ

摘要

PURPOSE: A method for manufacturing molten iron using semi-soft coking coal by compensating reducing gas in CDQ is provided to increase reduction ratio of iron ore by compensating shortage of reducing gas using CDQ. CONSTITUTION: In a method for manufacturing molten iron by a reduction furnace(2) for reducing ore with reducing gas and a melter-gasifier(1) for manufacturing hot metal with coal and reduced ore supplied from the reduction furnace and supplying the reducing gas into the reduction furnace, the method for manufacturing molten iron using semi-soft coking coal by compensating reducing gas in CDQ comprises a step of determining target furnace heat of the melter-gasifier(1) and the generation volume of a target reducing gas; a step of securing the target furnace heat by injecting coke along with semi-coking coal into the melter-gasifier(1) in case that furnace heat of the melter-gasifier(1) is lower than the target furnace heat during operation; and a step of compensating reducing gas by injecting a portion for CDQ (coke dust quenching) into a powder melting unit(10) of the melter-gasifier(1) if a generation volume of the reducing gas is reduced according to the coke injection.