废旧印刷线路板两步浸出有价金属

Two-step Leaching of Valuable Metals in Waste Printed Circuit Boards

为回收废旧印刷线路板中的有价金属,采用两步浸出的方法对其进行处理.先用双氧水-硫酸浸出贱金属,再用王水浸出贱金属浸出渣中的金.10 g废旧印刷线路板贱金属最佳浸出条件为双氧水20 mL,固液比1:5,硫酸浓度5 mol/L,反应温度60℃,反应时间90 min,原料溶损率达90.0%;金最佳浸出条件为反应温度40℃,反应时间30 min,浸出率达97.5%,研究证明两步浸出法能有效处理废旧印刷线路板,金溶出过程受扩散控制。

The two-step leaching was studied torecover the valuable metals in waste printed circuit boards（PCBs）.Firstly,sulfuric acid with hydrogen peroxide was used to leach the base metal;andsecondly,the aqua regiato leach gold in the base metal.The optimal base metal leaching conditions were as follows;hydrogen peroxide of 20 mL;solid-liquid ratio of 1：5;sulfuric acid concentration of 5 mol/L;reaction temperature of 60 ℃ and reaction time of 90 min.Thedissolution ratio of raw material（10 g） reached90.0%under the above conditions.The gold leaching efficiency reached 97.5%at 40 ℃ with reaction time of 30 min.Studies have shown that the two-step leaching can effectively deal with PCBs,and the gold dissolution process is controlled by diffusion.