METHOD OF MAKING STEEL IN ELECTRIC ARC STEEL MELTING FURNACE Russian patent published in 2007 - IPC C21C5/52 C21C7/06 

FIELD: ferrous metallurgy; methods of making steel in electric arc steel melting furnaces.

SUBSTANCE: proposed method includes delivery of scrap and molten cast iron to furnace, melting, reducing, tapping with slag and part of metal remaining in furnace. Prior to tapping, lime in the amount of 1-5% of mass of charge is added to furnace. Cast iron is poured at temperature of 1250-1360°C in the amount of 40-70% of mass of charge on slag and part of metal remaining in furnace. After pouring of cast iron, lime in the amount of 1-3% of mass of charge and scrap in the amount of 30-60% of mass of charge are charged into furnace. Oxidation is performed with oxygen at flow rate of 8000-12000 m³/h till content of carbon is no less than 0.10%. Silicon in the amount of 0.10-0.25% and manganese-containing ferro-alloys in amount of manganese of 0.40-0.50% are added to ladle at tapping; lime is added in the amount of 3-20 kg per ton of molten steel. Further bringing of the steel to specified temperature and chemical composition is carried out in the ladle-furnace unit.

EFFECT: improved quality of steel; reduction of melting time.