从次氧化锌烟尘中湿法回收锌及去除氟氯

Hydrometallurgical Recovery of Zinc and Removal of Chlorine and Fluorine From Zinc Oxide Dust

次氧化锌烟尘中的氯、氟离子对锌电解过程有不利影响。传统的前处理脱除氯氟技术存在成本高或产生二次污染等缺点。试验采用浸出—萃取—电积工艺回收锌及后处理去除氯氟工艺处理含氟、氯次氧化锌烟尘,制备的锌电解液中氯氟质量浓度低于传统湿法炼锌技术指标,解决了氯、氟离子对锌电积的危害问题,并使原料中的氯元素实现资源化,工艺无含盐废水排放。该工艺在国内某工厂已建成一条产业化生产线,生产的锌锭质量符合GB/T470—2008要求,锌回收率较高,所有过程均在常温、常压下进行,节能、环保、安全、运行成本低,市场前景广阔。

Secondary zinc oxide dust containing chlorine and fluorine is one of important secondary resources for zinc, but the chlorine and fluorine in it have bad influence on zinc electro-refining. Traditional removal methods for chlorine and fluorine can remove some impurities, but cost is higher or has secondary pollution for environment. In this study, a novel process of leaching- solvent extraction--electrorefining and post-processing of chlorine and fluorine for disposing the zinc oxide dust is proposed. The contents of chlorine and fluorine in zinc electrolyte are lower than that by traditional method. In addition,the chlorine resourceful utilization is realized and no saline wastewater discharges. Based on this process, a production line is set up. The zinc product can meet quality requirements of GB/T470--2008. The proposed technology has higher recovery rate of zinc, the advantages of energy saving, environmental protection, safety and low operation cost,and all processes of the technology are implemented under normal temperature and pressure.