Hydrometallurgical recovery of copper from complex mixtures of end-of-life shredded ICT products

• Selective leaching is a key step for metal separation and recovery from complex e-scrap.
• Ammonia leaching is more selective than H2SO4 for Fe-containing e-scrap recycling.
• Direct electrowinning of copper from ammonia-based solution is feasible.
• A more competitive recycling process requires further lab research for optimisation.

Hydrometallurgical recovery of copper from complex fine mixture scrap generated by shredding EoL (end-of-life) ICT (information and communications technology) products has been experimentally investigated. Tested leaching agents include sulphuric acid, ammonia–ammonium carbonate and ammonia–ammonium sulphate solutions, with or without addition of hydrogen peroxide. The results show that ammonia leaching has high selectivity for copper, and it could serve as a first step to recover the copper content in the e-waste, which is one of the major valuable metals. The feasibility of direct electrowinning of copper from the ammonia leaching solution with about 20 g/l Cu was investigated. Copper with 98.9% purity was obtained, with a current efficiency of 50–70% and the major impurity of Pb. The product purity could be improved with solution purification and adoption of inert anode.