Recycling of Gold From Waste Electrical and Electronic Equipment by Electrorefining of Copper

Abstract

This article presents the methods of processing gold-plated pins from, among others, used computer equipment and discusses the research results on the recovered metal. Due to the relatively small structure of the pins and the fact that the gold layer is only a few microns thick, recovering gold from them constitutes a significant challenge. On the other hand, gold is a precious metal which enables the collective removal of other metals to obtain pure gold. The suggested method involves compacting the gold-plated pins into an anode form and carrying out the electro-refining process. Metals, such as copper, tin and iron, pass into the anode sludge from which they can be extracted or serve as a commercial intermediate sold to smelter plants. The anode sludge was melted in the flame of an oxy-acetylene torch in a graphite crucible by adding borax. As a result of the melting, several metallic precipitates were obtained. Then they were hot-incorporated into a sample with a diameter of 30 mm and a height of 12 mm. Eventually, a pure gold alloy sample was obtained, which contains Cu 40.69%, Sn 9.61% and Au 48.58%.