100t复吹转炉终点温度控制对脱磷的影响

Influence of End-point Temperature Control on Dephosphorization for 100t Top and Bottom Combined Blown Converter Process

针对转炉高温脱磷困难的问题,根据某厂100 t转炉脱磷试验,研究了转炉终点温度控制对脱磷的影响及高温条件下增强转炉脱磷能力的措施。结果表明:随着出钢温度的升高,转炉渣-金磷分配比降低,炉渣脱磷能力变差,钢液磷含量增加。低温是转炉深脱磷的重要条件,出钢温度低于1 620℃时,即使碱度控制在3.0左右,也能实现磷含量低于0.01%出钢。通过提高炉渣碱度,增强炉渣固磷能力;降低渣中P_2O_5含量,增大炉渣磷容量;或增加炉渣FeO增强熔池氧化性和炉渣脱磷能力,均可显著降低高温对脱磷的不利影响,为出钢温度要求较高的低磷钢生产工艺参数控制提供了重要参考。

In order to address the dephosphorization problem of converter at the condition of high temper- ature, based on a 100 t converter dephosphorization experiments, the effect of end-point temperature con- trol in converter on dephosphorization and measures that increase the dephosphorization capacity of converter with high tapping temperature had been studied in this paper. It is found out that with the increase of temperature, the phosphorus distribution ratio of slag/metal decreases, the dephosphorization capabili- ty of slag degrades and llae liquid steel phosphorus content increases. Low temperature is an essential re- quirement for deep dephosphorization of converter. When the tapping temperature is lower than 1 620℃, it can realize tapping with liquid steel phosphorus content less than 0.01% even at - 3.0 of the slag ba- sicity. Increasing slag basicity leads to high absorption of phosphorus, while reducing P20s content in slag causes the increase of phosphate capacity of slag, and increasing Fe0 content in slag oxidizing atmos- phere of converter bath iincreased. All these three measures can reduce the negative effect of high tapping temperature on dephosp]horization.