Abstract: Based on theoretical analysis and calculation on converter dephosphorization and carbon-phosphorus selective oxidation transformation temperature, in condition of hot metal non-dephosphorizing-pretreatment, the production practice of double slag dephosphorization in 120 t top and bottom combined blown converter has been carried out. As the average 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 °C ) , 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% .

Key words: 120 t Top and Bottom Combined Blown Converter, Double Slag Process, First Deslagging Dephosphorization, Carbon-Phosphorus Selective Oxidation Transformation Temperature, Process Practice

摘要： 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。

关键词: 120 t顶底复吹转炉, 双渣法, 一次倒渣脱磷, 碳-磷选择性氧化转变温度, 工艺实践