保温时间对硅铁还原不锈钢渣的影响

Effect of Holding Time on Reduction of Stainless Steel Slag by FeSi

针对由于Cr6+溶出风险从而限制不锈钢渣作为二次资源再利用的问题,结合冶金热力学和动力学原理,采用X射线荧光光谱分析仪(XRF)和扫描电子显微镜(SEM)对不锈钢渣样品进行表征,研究在1 550℃条件下保温时间对不锈钢渣FeSi还原产物的存在形式和铬回收率的影响。结果表明:在添加质量分数为6%FeSi的条件下,随着保温时间的延长不锈钢渣中残余铬含量逐渐降低,铬的回收率逐渐增加,保温时间由5 min增加至30 min时铬的回收率从50.55%增加至86.05%;还原渣中残余铬以金属颗粒形式存在,且随着加热时间的延长,金属颗粒的数量减少、粒径增大。

In view of the problem of the elution risk of Cr6+that restrains utilization of stainless steel slag as raw material,combining with thermodynamics and dynamics principle of metallurgy,X-ray fluorescence spectrometer(XRF)and scanning electron microscope(SEM)were used to characterize the stainless steel slag samples.The effects of holding time at 1550℃on the occurrence of residual chromium and recovery rate of chromium in the stainless steel slag reduced with FeSi were investigated.The results show that under the condition of adding FeSi with mass fraction of 6%,the residual chromium content in the stainless steel slag gradually decreases with the increase of holding time,and the recovery rate of chromium increases gradually.When the holding time is kept from 5 min to 30 min,the recovery rate increases from 50.55%up to 86.05%.The residual chromium in the reduction slag exists in the form of metal particles,and with the extension of heating time,the number of metal particles decreases and the particle size increases.