METHOD OD STEEL PRODUCTION BY DUPLEX-PROCESS Russian patent published in 1994 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: metallic charge is loaded to the first converter at quantity 0.7-0.9 of the specific melt volume of the second converter. Oxygen feeding into the first converter is stopped after consumption of 3-3.5 kg per 1 kg cast iron silicon at superheating of slag relative to its melting point by 50-250 C. Bath is blown out with inert or reducing gas simultaneously with addition of reductants in the process of blowing. Ratio CaO/CaO/SiO₂ of the second converter slag to the that of the first one is at the range 3-8. Sulfur content in metal is decreased an average by 10 times, from 0.01 to 0.0015%. EFFECT: decreased sulfur content. 1 tbl