HCl-CuCl_2-NaClO湿法浸取手机元器件中的钯、金

通过HCl-Cu Cl2-Na Cl O湿法浸出体系对手机元器件中金属钯(Pd)、金(Au)进行浸出实验,研究不同因素对于Pd、Au浸出率的影响.结果显示,在2mol/L HCl、体积分数5%Na Cl O、0.075mol/L Cu Cl_2、固液比1%,反应温度60℃条件下,2h后Pd、Au浸出率均可达85%;结果表明,Cu^(2+)、Cl-、温度对于Pd的浸出率起很大作用,Na Cl O的加入可加快Pd浸出反应达到平衡速率;Na Cl O、温度对于Au的浸出率起关键作用,HCl、Cu^(2+)的加入可促进Au的浸出.因此,HCl-Cu Cl_2-Na Cl O湿法浸出体系对于Pd、Au具有良好的浸出效果.

Chlorine inclusion mechanism in high purity copper electrorefining from nitric acid system

A practical approach was introduced to study the inclusion mechanism of chlorine in high purity copper electrorefining from nitric acid system via cyclic voltammetry(CV) combined with electrodeposition experiments. The CV curves display an obvious reduction peak of Cu Cl intermediate, which can provide an insight into the electrochemical behavior of this inclusion. Experimental results show that the increase of HNO3 concentration is favorable to reducing the quantity of chlorine inclusion although there is a slight decline in cathodic current efficiency. The optimum conditions for copper electrorefining in nitric acid system are HNO3 concentration in solution of 1-2 mol/L, moderate temperature of ~35 ℃ with current density not exceeding 25 m A/cm2. Based on the theoretical studies, an optimized copper electrorefining experiment was designed to simulate the industrial electrolysis, by which high purity copper can be obtained with chlorine inclusion less than 10 μg/g and current efficiency higher than 90%.