The utilization of the precious and non-ferrous metal content of waste automotive connectors by mechanical pre-treatment and a subsequent pyrometallurgical method
Abstract
The waste of connectors used for electrical conduction in the automotive industry can be valuable secondary raw materials, as they contain significant concentrations of gold and copper. However, before metal recovery, it is first necessary to mechanically separate the gold-containing contact pins from non-metallic components, thus creating a metal concentrate rich in gold and copper. In this article, we examined the effectiveness of two methods. In the first case, the connectors were first shredded in a hammer shredder, and then magnetic separation was used to separate 97.02% of the gold and 76.16% of the copper into the magnetic product. In the second method, the connectors, which had undergone thermochemical treatment, were pre-shredded in a jaw crusher, ground further in a ball mill, and then classified by sieving. The material above 1 mm constituted the metal concentrate, which contained 99.4% of the gold content in the connectors. The pyrometallurgical utilization of the metal-rich fraction above 1 mm was investigated by metal-dissolving melting using molten copper as the solvent. Under optimal conditions, 99.1% of the gold content of the metal concentrate dissolved into the molten copper, resulting in a gold concentration of 0.26 g/kg in the alloy.
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