PROCEDURE FOR STEEL MELTING Russian patent published in 2011 - IPC C21C5/52 

FIELD: metallurgy.

SUBSTANCE: according to procedure on slag left in furnace and part of metal upon melt tapping there is charged solid iron at amount of 0-25% of charge weight, composite semi-product at amount of 25-60% of charge weight and lime at amount of 3.0-6.0 of charge weight. Upon melting solid metal charge at specific consumption of electric power 46-70 kWt-h/t of summary weight of solid iron and composite semi-product there is performed liquid iron pouring where contents of silicon is not above 0.60 % and phosphorus not over 0.10 % at amount of 40-50 % of charge weight. Melt is oxidised with gaseous oxygen at rate of 60-120 m³/h per ton of metal charge. Upon liquid iron pouring lime is added into the furnace by portions of 50-150 kg at amount of 0.1-0.2 % of metal charge weight. Carbonaceous powder is blown at rate of 25-180 kg/min.

EFFECT: reduced prime cost of steel, upgraded steel quality owing to reduced weight share of residual elements of chromium, nickel, copper and nitrogen, reduced duration of melting due to intensification of carbon oxidation, decreased lime and power consumption due to reduced oxidising period of melt.