Institute for Environmental Science and Technology, Hanoi University of Technology, 1 - Dai Co Viet, Hanoi, Viet Nam.
J Hazard Mater. 2010 Jun 15;178(1-3):1115-9. doi: 10.1016/j.jhazmat.2010.01.099. Epub 2010 Jan 25.
The present communication deals with the leaching of gold from the printed circuit boards (PCBs) of waste mobile phones using an effective and less hazardous system, i.e., a copper-ammonia-thiosulfate solution, as an alternative to the conventional and toxic cyanide leaching of gold. The influence of thiosulfate, ammonia and copper sulfate concentrations on the leaching of gold from PCBs of waste mobile phones was investigated. Gold extraction was found to be enhanced with solutions containing 15-20 mM cupric, 0.1-0.14 M thiosulfate, and 0.2-0.3 M ammonia. Similar trends were obtained for the leaching of gold from two different types of scraps and PCBs of waste mobile phones. From the scrap samples, 98% of the gold was leached out using a solution containing 20 mM copper, 0.12 M thiosulfate and 0.2 M ammonia. Similarly, the leaching of gold from the PCBs samples was also found to be good, but it was lower than that of scrap samples in similar experimental conditions. In this case, only 90% of the gold was leached, even with a contact time of 10h. The obtained data will be useful for the development of processes for the recycling of gold from waste mobile phones.
本通讯涉及使用一种有效且危害较小的系统（即铜-氨-连二亚硫酸盐溶液）从废弃手机的印刷电路板（PCBs）中浸出金，以替代传统的有毒氰化物浸金方法。考察了连二亚硫酸盐、氨和硫酸铜浓度对从废弃手机 PCB 中浸出金的影响。结果表明，在含有 15-20mM 铜、0.1-0.14M 连二亚硫酸盐和 0.2-0.3M 氨的溶液中，金的浸出率得到提高。从两种不同类型的废料和废弃手机 PCB 中浸出金时，也得到了类似的趋势。从废料样品中，使用含有 20mM 铜、0.12M 连二亚硫酸盐和 0.2M 氨的溶液可浸出 98%的金。同样，在类似的实验条件下，从 PCB 样品中浸出金的效果也很好，但低于废料样品。在这种情况下，即使接触时间为 10h，也只能浸出 90%的金。所得数据将有助于开发从废弃手机中回收金的工艺。
