| 摘要 |
PURPOSE:To quickly execute reduction of Cr2O3, etc., in Cr ore at high yield by mixing Mn ore or further borate mineral in semi-reduce sintered body at the time of producing Cr-containing molten iron by charging the semi-reduce sintered body of chromium ore, carbonaceous material, flux, etc., into the molten iron in a combined blowing converter. CONSTITUTION:The molten iron 8 is charged in the converter type reaction vessel 1 providing furnace bottom tuyeres 2 and top blowing lance 4, and while stirring the molten iron 8 by blowing gas of N2, Ar, CO, hydro-carbon, etc., from the tuyere 2, Cr ore, coke as reducing agent and lime or silica sand as the flux, are mixed from bunkers 6 and formed as pellet-state, semi-sintered and charged or solid raw material pre-reducing Cr2O3 and FeO with the coke while blowing oxygen through the lance 4, the Cr-containing molten iron is produced as the raw material for the stainless steel. In this case, by adding and containing the Mn ore or further the borate mineral of borax, colemanite, etc., in the above solid raw material, the m.p. of the molten slag 9 is lowered and the fluidity thereof is improved to reduce the Cr2O3 and FeO in the molten slag 9 at high yield for short time. |
