烧结机头电除尘灰的分级利用

摘要：以某钢铁企业烧结机头电除尘灰为原料,采用水浸-过滤-蒸发浓缩-冷却结晶工艺研究KCl的回收试验及浸出渣的再利用。研究浸出时间、液固比、搅拌速度和浸出温度等因素对KCl的回收效果的影响。结果表明：1号、2号电场除尘灰经过一次水洗浸出后,碱金属K、Na的脱除率分别达99.90%、99.99%和99.85%、99.93%,浸出渣铁品位为47.51%和43.90%,重金属Pb质量分数为0.14%和0.57%,浸出渣可返回烧结工序;3号、4号电场除尘灰经过二次水洗浸出后,碱金属K、Na的脱除率分别达99.34%、99.66%和99.38%、99.69%,浸出渣铁品位为35.19%和20.86%,重金属Pb质量分数为10.86%和14.50%,浸出渣可作为火法回收铅的原料。浸出液经过蒸发浓缩冷却结晶,得到产品中KCl质量分数为93.39%。

Classified utilization of sintering EAF dust

Sintering EAF dust was used as raw material for classified utilization.The recovery of KCl from the sintering precipitator dust was carried out by water leaching-filtration-evaporation concentration-cooling crystallization process.The effects of leaching time, liquid solid ratio, stirring speed and leaching temperature on the recovery of KCl were investigated.The results show that the removal rates of alkali metal K and Na from No.1 and No.2 electrical precipitator dust are 99.90%, 99.85% and 99.99%, 99.93%, respectively. The iron grade of the leaching slag is 47.51% and 43.90%, and the mass fraction of Pb is 0.14% and 0.57%, which can be returned to the sintering process.The removal rates of alkali metal K and Na from No.3 and No.4 electrical precipitator dust were 99.34%, 99.38% and 99.66%, 99.69%, respectively after the second leaching.The iron grade of the leaching slag is 35.19% and 20.86%, and the mass fraction of Pb is 10.86% and 14.50%, which can be used as a raw material for the recovery of lead by fire.The leaching solution is concentrated by evaporation cooling and crystallized to obtain the product with the KCl content of 93.39 mass%.