含镓锗硫酸盐溶液中砷铁的高效脱除

Efficient Removal of As and Fe from Sulfate Solution Containing Ga and Ge

砷和铁是湿法炼锌系统回收镓、锗工艺中主要的杂质元素,萃取分离工艺可实现砷铁的高效脱除,但得到的反萃液为高砷铁溶液,且含有少量镓、锗。为实现镓、锗的高效回收,采用中和沉淀法实现砷、铁与镓、锗的分离,考察沉淀终点pH、反应温度、反应时间、搅拌速度等参数对各金属离子沉淀率的影响。结果表明,在沉淀终点pH=2.5、反应温度25℃、反应时间1 h、搅拌速度240 r/min的最优条件下,铁和砷的脱除率分别为92.80%、98.13%,镓、锗的损失率分别为45.61%、7.35%。中和渣中损失的镓、锗可用弱酸溶液洗涤,酸洗液与中和后液共同返回到萃取系统回收镓和锗,提高综合回收过程中镓和锗的直收率。

As and Fe are the main impurity elements in zinc hydrometallurgy process of recovery of Ga and Ge,and the extraction process is usually applied to remove As and Fe,however,the obtained As and Fe strip solution generally contains a small amount of Ga and Ge.In order to achieve efficient recovery of Ga and Ge,As and Fe were separated from Ga and Ge by neutralization precipitation method,the effects of precipitation terminal pH value,reaction temperature,reaction time,stirring speed and other parameters on the precipitation rate of metal ions were investigated.The results show that the removal rate of Fe and As is 92.80% and 98.13% respectively,and the loss rate of Ga and Ge is 45.61% and 7.35% respectively under the optimum conditions including terminal pH value of 2.5,reaction temperature of 25 ℃,reaction time of 1 h,and stirring speed of 240 r/min.The Ga and Ge lost in the neutralizing residue can be washed with weak acid solution,and the pickling liquid and the neutralizing liquid are returned to the extraction system to recover Ga and Ge,so as to improve the direct yield of Ga and Ge in the comprehensive recovery process.