100t转炉冶炼钒钛铁水高效脱磷机理分析与生产实践

基于转炉出钢过程回磷机理分析与控制措施,通过现场取样、数据采集、模拟试验及利用FactSage软件分析了转炉冶炼过程脱磷机理,研究探讨了渣中FeO含量、TiO2含量、SiO2含量、终点温度、熔渣碱度、底吹搅拌对脱磷的影响。研究结果表明,结合首钢水城钢铁集团公司生产实践,控制终点温度在1 630~1 645℃、终渣FeO质量分数低于15%、SiO2质量分数为13.4%、碱度为3.5时,可促进富磷相C2S的生成和稳定存在,使脱磷率达84.42%及以上。同时,可高效控制熔渣含Ti量对熔渣脱磷效果的影响。维护较好的底吹效果可促进化渣,有效控制冶炼前期渣-钢界面温度在合适范围以促进脱磷,但较好的控制前期脱磷反应与脱碳反应的进行还存在一定技术难度。

Mechanism analysis and production practice of high efficiency dephosphorization of V-Ti hot metal in 100 t BOF

Based on the mechanism analysis and control measures of rephosphorization in the tapping,the dephosphorization mechanism of converter smelting process was analyzed by field sampling,data collection,simulation test and Factsage software. The effects of FeO content,TiO2 content,SiO2 content,end point temperature,basicity of slag and bottom blowing agitation on dephosphorization were studied. The results showed that the formation and stable existence of phosphorus rich C2S could be promoted and the dephosphorization rate could reach 84.42 % when the end point temperature was 1 630-1 645 ℃,w(FeO)<15 %, w(SiO2)=13.4 %,and the basicity was 3.5 in the final slag. At the same time,the effect of Ti content in slag on the dephosphorization effect could be effectively controlled. Maintaining a good bottom blowing effect could promote slag melting and effectively control the temperature of slag steel interface in the appropriate range to promote dephosphorization in the early stage of smelting. But there are still some technical difficulties in controlling the dephosphorization reaction and decarbonization reaction in the early stage.