Electrolysis Recovery Copper from Waste Printed Circuit Boards

Abstract

Abstract: The content of copper in waste printed circuit boards (WPCBs) is richer than that in ores. Therefore, recovery copper from WPCBs could protect copper resources. In this paper, copper recovery from WPCBs was carried out electrolytically by using sulfuric acid-copper sulfate system. The chloride ion from NaCl acted as a catalyst during the electrolysis process. Effects of CuSO4•5H2O quantity, NaCl quantity, H2SO4 concentration, and current density on current efficiency, surface morphology of cathode copper, and growth orientation were discussed. The results showed that current efficiency improved rapidly with the increase of CuSO4•5H2O quality and H2SO4 concentration. The addition of NaCl improved the surface morphological density of the recovered copper, however, the purity of cathode copper decreased when the NaCl quantity was more than 0.6 g. Meanwhile, a rougher surface morphology was formed when the concentration of H2SO4 and current density were in a higher range due to the reaction of hydrogen with the cathode surface. Under the optimal conditions (100 g/L CuSO4•5H2O, 6 g/L NaCl, 1 mol/L H2SO4, 500 A/m2, 3 h), the current efficiency reached 99.91% and the purity of cathode copper was 99.71%, indicating an effective copper recovery from WPCB metal powders containing assorted types of elements.

Keywords: WPCBs; recovery; copper; electrolysis