废旧印刷线路板两步浸出有价金属

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。

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

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) reached 90. 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.