Resources, Conservation and Recycling ( IF 13.2 ) Pub Date : 2022-09-01 , DOI: 10.1016/j.resconrec.2022.106631 H. Li, E.A. Oraby, J.J. Eksteen
The present study developed an integrated glycine-based process to recover metals from waste printed circuit boards at high solid contents (10–15%). A novel glycine-ammonia leaching was used to selectively extract >99% copper, >85% zinc and around 50% lead at room temperature. Ammonia played a key role, increasing the copper solubility in solution (>40 g/L), shortening leaching time from 72 to 24 h, and also acting as a pH modifier. The 2nd leaching step utilised cyanide-starved glycine where extractions of 70–90% for gold and silver, and >50% for palladium were obtained. The remaining metals from the previous steps were removed by ferric sulfuric acid leaching, with/without thiourea. In the presence of thiourea, 70–95% of remaining base and precious metals were removed. Overall, the metals with major economic value were all extracted at >99% for copper, >80% for gold, >90% for silver and >85% for palladium.
中文翻译:
开发基于甘氨酸的综合工艺从废印刷电路板中回收贱金属和贵金属
本研究开发了一种基于甘氨酸的集成工艺,用于从废印刷电路板中回收高固含量(10-15%)的金属。一种新的甘氨酸-氨浸出用于在室温下选择性地提取 >99% 的铜、>85% 的锌和大约 50% 的铅。氨起到了关键作用,增加了铜在溶液中的溶解度(>40 g/L),将浸出时间从 72 小时缩短到 24 小时,并且还充当了 pH 调节剂。第二个浸出步骤使用氰化物缺乏的甘氨酸,其中金和银的提取率为 70-90%,钯的提取率 >50%。先前步骤中剩余的金属被硫酸铁去除浸出,含/不含硫脲。在硫脲存在的情况下,70-95% 的剩余碱金属和贵金属被去除。总体而言,具有主要经济价值的金属均以> 99% 的铜、> 80% 的金、> 90% 的银和>85% 的钯金提取率。