Precious metals recovery from waste printed circuit boards: A review for current status and perspective

Abstract

Nowadays, rapid economic growth, continuous technological innovation and the improvement of living standards have result in large amounts of waste electric and electronic equipment (WEEE). Amongst all these WEEE, waste printed circuit boards (WPCBs) are considered as the most valuable components due to precious metals contained. Previous studies found that the presence of precious metals are richer in WPCBs than in typical metal mines, which are driven recycling precious metals from WPCBs to a profitable business without proper pollution controls in developing countries. However, recovering precious metals from WPCBs is a challenge because WPCBs are both valuable and harmful simultaneously, which are caused by their complex materials makeup. Hence, the proper technologies to recycle metals from WPCBs without negative effects to the environment and human health are urgent and essential. In this article, the current metals recycling technologies from WPCBs are reviewed. Then, an integrated technological route, including metals enrichment and precious metals recovery, is proposed. Finally, in order to promote the development of metals (precious metals) recovery from WPCBs, some improvements and recommendations in techniques and the future trend are also put forward.