Hydrometallurgy recovery of copper, aluminum and silver from spent solar panels

Given the daily increase in the number of spent solar panels scrapped worldwide, these materials can be recycled as value-added heavy-metal products because of their high contents of valuable metals, such as Cu, Ag. Firstly, spent solar panels were soaked in acetone solvent and then split into three parts: glass, silicon and ethyl vinyl acetate. The wafers were dissolved in nitric acid solution to produce a leachate with 16.3, 5.9 and 1.5 g/L Cu, Al and Ag, respectively. With the addition of 35 g/L oxalate, 98.9% Cu was separated from the system in the form of high-purity moolooite, whereas the loss of Al and Ag was less than 1%. In the hydrothermal process, with the addition of 3 g glucose and 30 g/L phosphate and under the reaction condition at 190 °C for 10 h, 98.7% Al can be separated efficiently from the system in the form of AlPO4, and the loss of Ag was less than 0.1%. Finally, almost all of the Ag can be recovered efficiently from the system in the form of chlorargyrite through the introduction of sodium chloride. The results of the study provide a way for the effective recycling of Cu, Al and Ag in spent solar panels.