Metals recovery: Study of the kinetic aspects of copper acidic leaching waste printed circuit boards from discarded mobile phones

This study was performed to investigate the possibility of copper recovery from the waste printed circuit boards (WPCBs) of waste mobile phones using a hydrometallurgical route as cleaner technology for environmental protection. In recycling, elements such as copper and aluminium are recovered, as well as the precious metals gold, silver, platinum and palladium, which can be recouped profitably from electronic waste and make this waste very valuable for recycling. In the experiments, the conventional agitated acid leaching method was used for mechanically pre-treated WPCBs with a mean Cu content of 19.09 wt % in a sulphuric acid medium with the presence of Fe³⁺ as an oxidant. The effects of Fe₂(SO₄)₃ concentration, leaching time, temperature and the ratio of liquid to solid phase on the recovery of copper from the solutions were studied. The highest Cu extraction was achieved at 363 K after 15 min of leaching, and a liquid to solid ratio (L/S) of 20. The value of activation energy (Ea), which was found to be ~14.87 kJ.mol^-1, indicates that this process is diffusion controlled. The apparent order of reaction with regard to the initial Fe₂(SO₄)₃ concentration at 313 K was calculated as 0.55. The proposed scheme of copper recovery from WPCBs of mobile phones was designed.