关键词: 120 t转炉半钢冶炼, 热补偿, 脱磷, 终点碳

Abstract: According to issue of increasing cost and decreasing liquid quality by BOF recarburization process to melt medium and high carbon steel using semi-steel at Pan Gang, the chemical thermal compensating process by increasing silicon content of semi-steel is adopted, and based on dephosphorization thermodynamics in BOF and enrichment regularity of phosphor in slag, it is obtaind that enrichment phase of phosphor in slag is 2CaO • SiO₂. By using technologic measures such as fast slagging, reduce tapping temperature, it is obtained that the enrichment phase of phosphor in slag is increased, which improve the dephosphorization effect. Results of test indicate that the new thermal compensating process improves the thermal resource of semi-steel as well as shorten the slag forming time from 4. 1 min to 2. 5 min,and the average carbon content of steel at endpoint is of BOF 0.18% , it is obtaind that temperature is 1653 °C ,TFe content of slag is average reduced by 2. 81 percent point,phosphor content of steel is all less than 0.015% .