Extracting gold from obsolete printed circuit board

Abstract

Japan is a major consumer of precious metals. Nevertheless, it imports most of its required amount of precious metals. In order to ensure a stable supply of precious metals as well as deal with the increasing global demand, it is important to develop coast effective and environmental-friendly technologies able to recover the precious metals from electronic waste, know as e-waste. Generally speaking the conventional method for recovering gold (Au) from printed circuit boars (PCB) involves the incineration of scarp, followed by acid leaching. In an attempt to improve the Au extraction process, the authors are putting forward a new method. The sample was first subject to carbonization in N2 atmosphere, followed by flotation in order to reduce the amount of sample subject to acid leaching as well as reduce the acid consumption. The flotation, the sample recovered by flotation was then treated with aqua regia to dissolve Au. After investigating the effect of the carbonization temperature, a Cost-Benefic Analysis and a Life Cycle Assessment (LCA) were carried out in order to compare the efficiency of both methods.