A New Route for Separating Impurities Al and Recovering Cu/Ag from Waste Solar Panels

With the increasing installation of solar panels, the number of discarded solar panels is also gradually rising, containing valuable metals such as Cu and Ag that can be recycled. This article investigates a new method for recovering Cu and Ag. Initially, acetone is used to soak the discarded solar panels, separating them into glass, EVA, back panel, and multicrystalline silicon. The multicrystalline silicon is leached with nitric acid, producing a leachate with Cu, Al, and Ag concentrations of 18, 5.6, and 1.7 g/L, respectively. By adding 15 g/L of glucose and 100 g/L of sulfates and heating the solution at 190 °C for 10 h, nearly 99.55% of Al is separated from the system in the form of natroalunite, with removal rates for Ag and Cu being only 0.09 and 1.10%, respectively. Through the addition of NaCl, approximately 99% of Ag is effectively recovered from the system in the form of chlorargyrite. Finally, by adjusting the pH, approximately 98% of Cu is recovered in the form of covellite. This study provides a novel approach for the efficient recovery of copper, aluminum, and silver from discarded solar panels.