Abstract: According to calculation, for SP etc. low carbon steels the adding scrap ratio to control converter liquid end temperature is no less than 16% , but present scrap supply for 120 t converter is only up to 13% , led to liquid end temperature higher to effect lining life. According to analysis, the end temperature of liquid in converter is adjusted and controlled by adding limestore (/% : ≥53.0CaO, ≤1.2SiO₂, ≤0.40S, ≤0.008P). The production practice with 54 heats show that as adding 500-1000 kg limestone with liquid temperature 1 660-1669 Y , liquid average temperature dropped by 3.6-8.0 ℃ , 1670-1679 °C , dropped by 4.9-10.8 P , and m 1680 ℃ , dropped by 9.0-20.0 ℃ ； by adding limestone the average liquid dephosphorizing ratio is 83% , it is basically about equal to the dephosphorizing ratio (87% ) by adding iron ore.

Key words: Top and Bottom combined Blowing Converter, Scrap, Limestone, Control of End Temperature, Practice of Process

摘要： 经计算,对SP等低碳钢控制钢水终点温度的废钢比应不低于16%,但目前120 t转炉废钢供应只能达到13%,造成钢水终点温度偏高,影响炉衬寿命。经过分析,采用添加石灰石(/%:≥53.0CaO、≤1.2SiO₂、≤0.040S、≤0.008P)调节转炉终点钢水温度。经54炉次生产实践表明,当添加500~1000 kg石灰石,钢水温度1660~1669℃时平均降温3.6~8.0℃,1 670~1 679℃时,降温4.9~10.8℃,≥1680℃时降温9.0~20.0℃;加石灰石的钢水平均脱磷率为83%,与铁矿石的平均脱磷率(87%)基本相当。

关键词: 顶底复吹转炉, 废钢, 石灰石, 终点温度控制, 工艺实践