METHOD OF PIG IRON CONVERSION Russian patent published in 2002 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: method includes two stages with production of low-silicon semiproduct with slag from pig iron filled into steel-melting unit at the first stage, and steel at the second stage. Flux is used in the form of liquid slag formed in treatment of metal on ladle-furnace installation. Metal is filled into transfer ladle before introduction of low-silicon carbon semiproduct. Then low-silicon carbon semiproduct is filled together with obtained slag into the second steel-melting unit, where it is subjected to oxidizing refining with addition of slag-forming materials up to preset content of carbon and other components. Slag formed in metal treatment on ladle-furnace installation contains, mas.%: MgO, 8-15; FeO, 0.5-5.0; with basicity, 2-4. Low-silicon carbon semiproduct before tapping into transfer ladle has temperature of 1350-1450 C. Initial pig iron may be used in the form of vanadium pig iron. Low-silicon carbon semiproduct is produced together with vanadium slag and poured into transfer ladle together with vanadium slag whose amount is 2-4 kg/t of low-silicon carbon semiproduct. EFFECT: higher degree of pig iron desulfurization and dephosphorization, increased stability of converter lining and improved heat balance of heat. 4 cl, 1 tbl