120t顶底复吹转炉双渣脱磷一次倒渣的工艺实践

Practice on First Deslagging Process of Double Slag Dephosphorization in 120t Top and Bottom Combined Blown Converter

通过对转炉脱磷和碳-磷选择性氧化转变温度的理论分析和计算,在铁水未经脱磷预处理的条件下,进行120 t顶底复吹转炉双渣脱磷生产实践。当铁水平均成分为(/%):4.81C、0.49Si、0.32Mn、0.127P、0.019S的情况下,在转炉冶炼前期(0~360 s),采用低温(1 330~1 350℃),较强底吹搅拌[0.030~0.040 m^3/(t·min)],中等炉渣碱度(2.0~3.0)和高氧化铁(20%~25%)工艺措施,实现一次倒渣的半钢(3.8%C)平均磷含量0.048%和平均脱磷率62.2%的脱磷效果。

Based on theoretical analysis and calculation on converter dephosphorization and carbon-phosphorus selec tive oxidation transformation temperature, in condition of hot metal non-dephosphorizing-pretreatment, the production prac tice of double slag dephosphorization in 120 t top and bottom combined blown converter has been carried out. As the aver age analysis of hot metal is （/%） 4. 81C, 0. 49Si, 0. 32Mn, 0. 127P and 0. 019S, in converter blowing early period （0 360 s）, with the process measures including more intensifying bottom stirring [0. 030 - 0. 040 m3/（ t . min） ] at lower temperature （ 1 330-1 350 ℃ ） , medial slag basicity （2.0 - 3.0） and high ferrous oxide （20% - 25% ） , the average phosphorus content in semi-steel （3.8% C） after first deslagging process is 0. 048%, i.e. the average dephosphorization rate is 62. 2%.