复吹转炉双渣深脱磷工艺实践

Practice of double slag deep dephosphorization technology in combined blown converter

为了提出适合南钢的操作原则和控制目标,根据转炉脱磷反应基本热力学原理和复吹转炉双渣脱磷工艺特点,针对南钢铁水条件,分析了铁水硅含量、温度、磷含量对脱磷的影响并提出合理的冶炼方案.南钢120t复吹转炉双渣深脱磷工艺实践表明,通过优化造渣、供氧、一次倒渣及终点控制等工艺操作,能取得转炉终点钢液磷的质量分数≤40×10-6和脱磷率达97.3%的脱磷效果.按照优化后的方案进行冶炼能满足南钢超低磷钢的生产需要.

In order to present the operating principles and the appropriate control objectives for Nan Steel,according to dephosphorization theory and characteristics of double slag dephosphorization in combined blown converter,together with the conditions of molten iron in Nan Steel,the influences of silicon content,temperature and phosphorus content on dephosphorization were analyzed and the reasonable smelting solution was presented. The result shows that it can achieve the dephosphorization effect that phosphorus content is less than 4 × 10- 5and the dephosphorization rate is 97. 3%,by using the optimizing process operation of slagging,oxygen blowing,first deslagging and end-point control,in Nan Steel 120 t combined blown converter. The need of ultra-low phosphorus steel produce can be met through the optimized solutions.