Selective recovery of copper from metal-rich particles in waste printed circuit boards by mechanical processing

Abstract: This paper proposes a ball mill for the selective beneficiation of copper from metal-rich particles without any chemical treatment. Before ball milling, improved metal-rich particles were obtained through pretreatment including magnetic separation, crushing and separating. The effect of grinding time on the metal grade and recovery of copper (Cu), tin (Sn) and lead (Pb) was investigated. The results showed that there was a selective increase in Cu content in the concentrates during processing. In addition, Sn and Pb were enriched in tailings. Under optimum grinding cycles, the copper grade was beneficiated to 94.72 wt% from the initial 74.22 wt%, and its recovery rate was 86.78%. The content of tin and lead was increased to 28.27 wt% and 18.86 wt% from 10.13 wt% and 6.63 wt% in the by-products, respectively. The selective enrichment is due to the different plasticity and strengthening capacity of the components. The whole mechanical process is environmentally friendly, and the results will be useful for sustainable recycling of DPP.