METHOD OF MAKING STEEL IN ELECTRIC ARC FURNACE Russian patent published in 2005 - IPC

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

SUBSTANCE: proposed method includes charging the scrap and lime. After melting of scrap at power requirement of 180-300 kW.h/t, molten cast iron is poured from above at temperature of 1280-1400°C in the amount of 30-60% of mass of charge; charge contains the following components, mass-%: C, (2.0-3.5); Si, lesser than 0.01; P, lesser than 0.015; S, lesser than 0.025. Carbon is oxidized with gaseous oxygen at temperature in furnace not above 1700°C. At tapping the steel, furnace slag is cut off and is left in furnace in the amount of 10-15% of total mass of molten metal. During tapping, slag-forming mixture is fed to ladle; this mixture contains lime and fluorspar at ratio of (0.8-1.2) : (0.2-0.5) at rate of 10-17 kg/t of steel; ferro-alloys are added to mixture.

EFFECT: reduced power requirements; reduced consumption of electrodes; reduced melting time; improved quality of steel; reduced consumption of deoxidants and alloying agent.