湿法炼锌系统氯化亚铜脱氯生产流程优化实践

Optimization of production process of dechlorination by cuprous chloride in zinc hydrometallurgy system

某湿法炼锌厂将原有黄钾铁矾工艺改为常规浸出工艺,高氟氯次氧化锌返回湿法系统回收利用,导致系统氯含量急速升高,亟需增加脱氯工艺。该厂决定采用氯化亚铜脱氯,在实施过程中,出现了净液铜渣难浸出、脱氯率不稳定和沉铜过程存在AsH 3逸出风险等。对这些问题详细分析后,进行了相应的改进,改进后效果明显,脱氯效率稳定在83%以上,能较好的切合湿法炼锌主体工艺,且铜渣经碱洗可实现循环利用,具有良好的工业适用性。

A zinc smelter changed the original low-pollution jarosite process to a conventional leaching process,and return the high fluorine chlorine zinc oxide to zinc hydrometallurgy system,which lead to a rapid increase of the chlorine content in the system,and urgently need to add the dechlorination process. The plant decided to adopt the cuprous chloride dechlorination process. During the implementation,some problems occurred such as difficult leaching of the purification copper slag,unstable dechlorination rate,and the risk of AsH3 escape during the copper precipitation process. After a detailed analysis of these problems,corresponding improvements were made,and the effect is obvious. The dechlorination efficiency is stable above 83%,and it can better fit the main process of zinc hydrometallurgy system,and the copper slag can be recycled by alkali washing. The improved dechlorination process has good industrial applicability.