Department of Solid Waste Treatment and Recycling, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Department of Solid Waste Treatment and Recycling, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Waste Manag. 2022 Nov;153:13-19. doi: 10.1016/j.wasman.2022.08.011. Epub 2022 Aug 24.
The present study reports a sequential, non-acid process for effective recovery of copper and precious metals from mobile phone printed circuit boards. In this process, gold and silver were first enriched during the synthesis process of cuprous chloride and then leached by thiosulfate method. Results indicated that the distribution of gold and silver in the liquid and solid phases during the synthesis of cuprous chloride process was affected by the [Cu]/[Cu] ratio. Enrichment of gold and silver in the residue after the cuprous chloride synthesis could be achieved by the adjusting the [Cu]/[Cu] ratio. The silver and gold leaching rates of the residue after cuprous chloride synthesis (93.8 % silver and 99 % gold) were much higher than those of the raw PCB sample (27.0 % silver and 14.2 % gold) under the same conditions. This process has the advantages of high leaching efficiency, high leaching rate and avoiding the use of HNO or aqua regia commonly used for copper, gold and silver recovery. Thus, this study offers a promising and environmentally friendly method for recovering valuable metals from e-waste.
本研究报告了一种从移动电话印刷电路板中有效回收铜和贵金属的连续、非酸性工艺。在该工艺中，金和银在氯化亚铜合成过程中首先被富集，然后用硫代硫酸盐法浸出。结果表明，在氯化亚铜合成过程中，金和银在液-固相间的分布受[Cu]/[Cu]比值的影响。通过调整[Cu]/[Cu]比值，可以在氯化亚铜合成后从残渣中富集金和银。在相同条件下，氯化亚铜合成后残渣的银和金浸出率（93.8%的银和 99%的金）远高于原始 PCB 样品（27.0%的银和 14.2%的金）。该工艺具有浸出效率高、浸出率高、避免使用通常用于回收铜、金和银的 HNO 或王水等优点。因此，本研究为从电子废物中回收有价值的金属提供了一种有前途和环保的方法。
