The invention relates to a carbon blowing technique for electric furnace
smelting. The method comprises the following steps: a. filling carbon
powder: screening carbon
powder to obtain carbon
powder of which the
granularity phi is at most 3mm, the
water content is at most 3% and the
sulfur content is at most 2.5%, and filling the screened carbon powder in a supplementary blowing
machine (1); b. adjusting pressure of
compressed air: respectively adjusting the pressure of the supplementary blowing
machine (1) and the pressure of the self-consumption carbon blowing gun (3) to 0.2-0.3 MPa; c. opening a carbon powder baiting valve of the supplementary blowing
machine; d. inserting the self-consumption carbon blowing gun (3) into
molten steel of an
electric arc furnace melting bath (4) via a furnace
slag layer (5); and e.
electric arc furnace
smelting by charging three times: when the temperature of the melting bath is increased, melting down
scrap steel, starting the supplementary blowing machine to blow the carbon powder into the melting bath three minutes a time, and tapping after the steel meets the
chemical composition requirement for steel grade Q235 and achieve the tapping conditions. The invention can save
electric energy, increases the steel
scrap recovery rate, is simple to operate, and has the advantages of simple equipment and strong feasibility. By adopting the carbon blowing technique, the
electricity can be saved by 30 KWH per
ton of steel, and the steel
scrap recovery rate can be increased by more than 1%, the comprehensive economic benefit per
ton of steel is more than 50 Yuan. If the technique is used for electric furnace
smelting all over China, 10 billion Yuan can be saved every year.