PRODUCTION OF REDUCED IRON

摘要

PURPOSE:To prevent deposition of C in a shaft furnace and prevent the decrease in the productivity of the furnace by adding a specific amt. of H2S to the reducing gas used in producing reduced iron in the shaft furnace. CONSTITUTION:Iron ore B is charged into a shaft furnace 8, and a reducing gas consisting essentially of H2, CO formed with a steam reformer 1 is blown therein to cause solid phase reduction of the iron ore, whereby reduced iron is produced. At the stage of generating the reducing gas consisting essentially of H2, CO by blowing gaseous hydrocarbon 3 together with steam 4 into the steam reformer 1 and supplying said gas into the furnace 8, gas A such as H2S, CS2, or (NH4)2S is added through a heating furnace 20 into a reducing gas conduit 6, so that the concn. of H2S in the reducing gas at the inlet of the furnace 8 is kept at >=10vol.ppm. The deposition of C in the furnace is obviated despite the small content of CO2, H2O in the reducing gas and the reduction is accelerated, whereby the productivity of the furnace is improved.