METHOD OF STEEL MAKING IN ARC-TYPE ELECTRIC STEEL MAKING FURNACE Russian patent published in 2015 - IPC C21C5/52 

FIELD: metallurgy.

SUBSTANCE: method involves supply to a furnace as metal stock of metal scrap and liquid cast iron, melting of metal scrap, addition of slag-forming materials, oxygen blowing and tapping. Liquid cast iron casting is performed in the amount of 40-70% of metal charge weight. After that, bath oxygen blowdown is performed at the flow rate of 1800-2200 nm³/h during 12-25% of the blowdown time. Then, oxygen consumption is increased to 5000-7000 nm³/h and blowdown is performed in the specified mode during 28-40% of blowdown time. Then, oxygen consumption is reduced to 3000-5000 nm³/h and blowdown is performed in the specified mode till it is completed. During the bath blowdown with oxygen consumption of 5000-7000 nm³/h feeding of coke powder in the amount of 25-60 kg/min is performed. As slag-forming materials, lime is added in the amount of 15-65 kg/t of steel and/or lime is added in the amount of 2-20 kg/t of steel, and dolomite is added in the amount of not more than 10 kg/t of steel.

EFFECT: reduction of electric power consumption and increase of steel making efficiency.

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