锌浸出渣浮选银的预处理研究

在锌精矿的沸腾焙烧过程中,温度高于650℃时,生成的氧化锌及氧化铁结合成铁酸锌,是一种难溶于稀硫酸的铁氧体,全部留在浸出渣中。高温高酸浸出条件控制愈好,铁酸锌被溶解的愈多,硫化锌被破坏的就愈彻底,渣含锌就愈低,金属回收率就愈高,而且有利于银的浮选。针对某冶炼厂湿法炼锌渣,采用高温高酸浸出和浮选的方法回收锌、银,高温高酸浸出液经过除铁得到的溶液返回锌系统回收锌,高温高酸浸出渣经过一次粗选两次精选三次扫选的试验流程,得到了品位达到了2017.45g/t,回收率达到78.44%的银精矿。

Flotation of Silver by Pretreatment from Zinc Leaching Residue

The zinc ferrite formed by zinc oxide and iron oxide is generated from the roasting process of zinc concentrate at the temperature of more than 650℃,which is a kind of ferrite insoluble in dilute sulfuric acid,but remaining in the leaching residue.The better control of high temperature and high acid leaching conditions,the more the zinc ferrite was dissolved,the more thoroughly the zinc sulfide was destroyed,the lower the slag containing zinc is and the higher the metal recovery rate is,benefiting the flotation for silver.Directed at the zinc slag hydrometallurgy,using the method of high temperature and high acid leaching and flotation to recovery zinc and silver,the solution obtained from the high temperature and high acid leaching solution by means of dividing iron was returned to zinc system to recover zinc.By adopting the process of one roughing two cleaning three scavenging,the silver concentrate with the grade of 2017.45g/t and the recovery of 78.44%was obtained.