硫代硫酸盐法浸出废旧IC芯片中金的试验研究

Experimental study of gold leaching from waste IC with thiosulfate

介绍了当前电子废弃物中常用的浸金方法及其优缺点,分析了电子废弃物中硫代硫酸盐法浸金的研究现状。针对这一研究现状,本文采用碱性Na2S2O3溶液中添加Cu2+的方法,对废旧IC(integratedcircuit)芯片中金的浸出进行了试验研究。通过对IC样品进行机械预处理、粒度分析、解离度分析、化学预处理和浸金试验,探讨了Na2S2O3浓度、Cu2+浓度、NH3浓度、浸出温度、浸出时间和反应液固比6个因素对金浸出率的影响。试验得出最佳浸金条件为:Na2S2O3浓度0.3mol/L,Cu2+浓度0.03mol/L,NH3浓度0.5mol/L,添加3.5g/L的Na2SO3作为稳定剂,浸取温度50℃,浸取时间2.5h,液固比10∶1,在最佳浸出条件下,金的最高浸出率为92.25%。与传统方法相比,该方法具有浸出速度快、浸出液无毒、操作简单等优点,是一种具有开发潜力的电子废弃物浸金方法。

This paper described the current commonly e-waste gold leaching methods,their advantages and disadvantages, and analyzed research status of e-waste thiosulfate gold leaching. Gold leaching from waste integrated circuit（IC） using the alkaline sodium thiosulfate solution with copper iron was investigated. Through the mechanical pretreatment, particle size analysis, dissociate-ion analysis,chemical pretreatment and gold leaching experiments, the effects on gold leaching rate of Na2S2O3 concentration,Cu2＋ concentration,NH3 concentration,temperature,leaching time and liquid to solid ratio were discussed,and optimum gold leaching conditions were obtained ：0.3mol/L of Na2S2O3,0.03mol/L of Cu2＋,0.5mol/L of NH3,3.5g/L of Na2SO3 as the stabilizer,leaching temperature of 50℃,leaching time of 2.5h,liquid to solid ratio of 10∶1. Under these conditions,the highest rate of gold leaching was 92.25%. Compared with traditional methods, the new method had advantages of fast leaching speed,non-toxic leachate and easy operation.