铅冶炼次氧化锌烟灰浸出脱氯试验研究

Experimental study on leaching and dechlorination of secondary zinc oxide soot

次氧化锌烟灰主要成分为氧化锌,具有易于浸出且锌回收率高的特点,但随着氟、氯等元素增多,对后期的锌浸出及电积工艺控制造成很大的影响。高效去除次氧化锌烟灰中的氟氯成为锌冶炼行业研究的重点内容。通过单因素试验,以水和碳酸钠溶液作为浸出剂,分别考察液固比、浸出温度、浸出时间、pH等因素对铅冶炼生产过程产生的次氧化锌烟灰中氯离子脱除率及锌离子损失率的影响,并确定最佳工艺参数。结果表明,采用碳酸钠碱性浸出,液固比8∶1,浸出温度45℃,浸出时间100 min,pH=11.0,在此优化参数下,氯离子脱除率可达到87.43%,锌损失率为0.5%。

The main component of secondary zinc oxide soot is zinc oxide,which is easy to leach and has a high zinc recovery rate.However,with the increase of elements such as fluorine and chlorine,it has a significant impact on the later zinc leaching and electrowinning process control.Efficient removal of fluorine and chlorine from zinc oxide ash has become a key focus of research in the zinc smelting industry.A single factor experiment was conducted to investigate the effects of factors such as liquid-solid ratio,leaching temperature,leaching time,and pH value on the removal rate of Cl and the loss rate of Zn in secondary zinc oxide ash produced by lead smelting,using water and sodium carbonate as leaching agents.The process optimization parameters were determined to be:alkaline leaching with sodium carbonate,liquid-solid ratio of 8∶1,leaching temperature of 45℃,leaching time of 100 minutes,and pH value of 11.0.Under these optimization parameters,the chlorine removal rate reached 87.43%,the zinc loss rate is 0.5%.