METHOD OF CONVERTER STEEL MAKING Russian patent published in 2003 - IPC

FIELD: metallurgy; converter steel making. SUBSTANCE: proposed method includes delivery of metal charge to converter; molten iron in the amount of 0.6 to 0.9 of charge is included in charge. Then, solid cast mixture of cast iron and oxidant-containing materials in the amount of 0.1-0.4 of mass of metal charge is fed and slag-forming materials are added . Melt is blown with oxygen at flow rate of 2.2-4.5 cu m/min per ton of melt. Blowing is started at position of tuyere above level of melt in killed state at distance H₁, equal to 100-180 critical diameters of tuyere nozzles. Then in 0.1-4.0 minutes tuyere is lowered to distance H₂ equal to 40-60 critical diameters of tuyere nozzles. Total flow rate of oxygen since beginning of blowing melt to lowering tuyere to distance H₂ is set in the amount Q = K/m, where m is content of oxidants in metal charge equal to 0.5-10.0% and K is empirical coefficient equal to 2.3-270.0 cu m %/t. Then, tuyere is lowered stepwise from level H₁ to level H₂ during 2-5 min at 3-15 steps. EFFECT: enhanced economical efficiency; guaranteed composition of metal. 2 cl, 1 tbl