Study of a novel electrochemical method for copper recovery from waste printed circuit boards

Abstract

This study was carried out to recover copper from printed circuit boards of waste computers through an electrochemical process. To simplify the overall recovery process, large pieces of printed circuit boards were used instead of pulverized samples. In particular, these large pieces were directly used as an anode for copper electrorefining. For this purpose, electronic components and solder mask were initially removed from the boards. The electronic components can be treated separately to recover precious metals using various methods. The removal of solder mask was necessary to expose copper layers to the electrolytic solution and it was removed by a chemical treatment with sodium hydroxide. Electrolytic solution was a mixture of copper sulphate and sulphuric acid, and was maintained at 60°C during the process. The recovery of copper was conducted in an electrochemical cell where the anode was supplied by a constant current of 900 mA. The deposited copper was characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Results show a uniform cathodic deposit of pure copper having a thickness of about 32.35 μm. The copper current efficiency was of 84% with a removal degree of copper from printed circuit board of about 46%.