Recovery of Cu and Zn from waste printed circuit boards using super-gravity separation

With technological innovation and intense marketing, more and more electric and electronic equipment wastes (e-wastes) are being generated. Printed circuit boards (PCBs) are fundamental components of electronic wastes, which consist of both valuable metals and hazardous materials. An efficient method to recycle metals is an important measure to eliminate or avoid heavy metal hazard and realize resource recovery. In this research, super-gravity separation achieved by high temperature centrifugation was used to recover copper and zinc from waste PCBs. At an optimized temperature of 1300 °C and a gravity coefficient of 1000, the total recovery values of Cu, Zn, Pb, and Sn were 93.23%, 80.86%, 94.54%, and 97.67%, respectively, in the whole separation process. By combining appropriate hydrometallurgy and super-gravity separation of metals or alloys, this clean and efficient process provides a novel way to recycle valuable metals and effectively prevent environmental pollution from PCBs. A large-scale experimental apparatus was designed for handling large volume of WPCBs.