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

FIELD: metallurgy; particularly, production of steel in electric arc furnace. SUBSTANCE: method of steel melting in electric arc furnace incorporates steps of charging and additional charging of batches of metal-based charge being charged once only into furnace bath, melting and refining of melt up to required temperature and composition owing to utilization of electric arcs power and other alternative power supply sources for melting with usage of crushed limestone as slag-forming material. Limestone is introduced into arcing zone in the form of lump material with fraction of 20-80 mm size at natural moisture content not more than 2.0-5.0 %, with MgO content not less than 2.0-2.5 % and compression strength not more than 450 kg/m². Limestone is delivered into furnace after consumption of 90-130 kW.h/t of electric power from the beginning of melting of each metal-based charge. Limestone is introduced into furnace by compact batches in the amount of 220-300 kg with rate of charging into bath from 0.9 to 1.2 kg/min, for the period of supply of one kW.h/t of electric power, maintaining its total consumption for the period of melting within the range from 50 to 55 kg/t. EFFECT: extension of technical capabilities and enhancement of technical and economic indices of melting with usage of limestone as slag-forming material. 3 cl, 1 ex