METHOD OF MAKING STEEL IN HIGH-POWER ELECTRIC ARC FURNACES Russian patent published in 2003 - IPC

FIELD: ferrous metallurgy; making steel in electric arc furnaces. SUBSTANCE: proposed method requires 15-70% of mass of metal part of charge of molten conversion pig iron of blast-furnace smelting. Then, 40-70% of lime and 10-20% of fluorspar of total amount of their consumption are charged and oxygen blowing is effected through roof tuyere for 3-5 minutes, thus obtaining melt; 30-50% of steel scrap of mass of metal charge is charged, furnace is switched-on and oxygen is supplied. After melting of main mass of charge, required amount of steel scrap and slag-forming components are added; then, oxidizing refining is performed and after preset content of carbon and phosphorus in metal and temperature have been obtained, metal is subjected to retreatment in complex furnace-ladle set. EFFECT: increased productivity; reduced power requirements; enhanced purity of steel as compared with steel obtained from metallized pellets. 1 tbl, 1 ex