Extraction of Ag and Au from chloride electronic waste leach solutions using ionic liquids
Extraction of Ag and Au from chloride electronic waste leach solutions using ionic liquids
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DOI：
10.1016/j.jece.2018.11.054
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发表时间：
2019-02-01
影响因子：
7.7
通讯作者：
Ndlovu, Sehliselo
中科院分区：
文献类型：
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作者：
Masilela, Mthobisi;Ndlovu, Sehliselo
电子废物（电子废物）含有金属等有价值的材料。这些可以使用常规的火法冶金或湿法冶金工艺来回收。然而，这些现有的金属回收技术具有许多限制，例如不利的环境足迹和高能量成本。这就需要研究替代方法或试剂。在这项研究中，离子液体; [Bmim] [Tf 2N]，[Bmim] [PF 6]，和Cyphos 101作为萃取剂的银和Au从氯化物王水浸出液的印刷电路板样品，具有162 gt（-1）Au和618 gt（-1）Ag。发现所使用的离子液体是用于从浸出液中萃取Au的有效萃取剂，在所有测试的离子液体中萃取超过90%的Au。然而，发现Ag浸提低于Au，[Bmim] [Tf 2N]未记录浸提，但Cyphos 101和[Bmim] [PF 6]均记录了超过90%的浸提。这表明离子液体是从氯化物介质中回收Au和Ag的潜在替代萃取剂。考虑到成本和效率，Cyphos 101被证明是在室温和IL：样品比为1：1的情况下从氯化物溶液中提取所有金属的最有效的萃取剂。在此条件下，银、Au和铜的浸出率分别为95%、97%和99%。
Electronic waste (e-waste) contains valuable materials such as metals. These may be recovered using conventional pyrometallurgical or hydrometallurgical processes. However, these existing metal recovery techniques have a number of limitations such as adverse environmental footprints and high energy costs. This then necessitate an investigation into alternative methods or reagents. In this research, ionic liquids; [Bmim] [Tf2N], [Bmim] [PF6], and Cyphos 101 were investigated as extractants for Ag and Au from chloride aqua regia leach liquors of printed circuit board samples, with the composition of 162 gt(-1) Au and 618 gt(-1) Ag. The ionic liquids used were found to be efficient extractants for Au extraction from the leach liquor, with more than 90% of Au extracted in all the ionic liquids tested. Ag extraction was however, found to be lower compared to Au with no extraction recorded for [Bmim] [Tf2N] but over 90% extraction was recorded for both Cyphos 101 and [Bmim] [PF6]. This showed that ionic liquids are potential alternative extractants for the recovery of Au and Ag from chloride media. Considering both costs and efficiency, Cyphos 101 proved to be the most effective extractant for all metals from chloride solution at room temperature and 1:1 of the IL: sample ratio. The extractions were 95% Ag, 97% Au and 99% Cu under these conditions.