METHOD OF MAKING STEEL IN ELECTRIC ARC STEEL- MELTING FURNACE Russian patent published in 2003 - IPC

FIELD: methods of making steels in electric arc steel-melting furnaces. SUBSTANCE: proposed method includes charging scrap into furnace, pouring molten iron, melting metal charge, dephosphorization of steel by means of additives of iron ore or sinter mixed with lime, deoxidation of steel and slag in furnace, tapping steel to ladle under furnace slag, adding desulfurizing mixture consisting of lime, feldspar and aluminum powder to ladle. Sinter or iron ore is introduced in charge in the amount of 30-60 kg/t of steel. After deep fusion of metal charge, molten iron is poured into furnace at power requirement of 220- 320 kW h/t of scrap, temperature not below 1200 C and pouring rate of 6- 12 t/min; then, oxidation with gaseous oxygen is performed at rate of 1500-3000 cu nm/h. Ratio of iron ore or sinter added in mixture with lime is maintained at (1-2) : (2.5-3.5) at rate of 70-110 kg/t of steel. Then, slag is drained through sill of working door. Ratio of lime, feldspar and aluminum powder is maintained respectively at (1.1-1.5) : (0.3-0.5) : (0.05-0.1) at consumption of mixture of 14 to 18 kg/t of steel. Proposed method provides for reduction of power requirements and consumption of electrodes. EFFECT: reduced power requirements; reduced melting time; improved quality of steel.