Advances in Electrochemical Technologies for Metal Recovery from E-Waste

The rapid growth of electronic waste (e-waste) has made this stream both an environmental challenge and a valuable secondary source of critical raw materials. Global e-waste generation reached approximately 62 Mt in 2022, while printed circuit boards may contain around 15–30 wt.% Cu, illustrating the considerable resource potential of this waste stream. Recovering these metals is essential to reduce dependence on primary mining and support the transition towards a circular economy. Although pyrometallurgical and hydrometallurgical processes remain the basis of industrial e-waste recycling, they are often constrained by limited selectivity, high energy and reagent consumption, and the need for extensive downstream purification. This review examines the contribution of electrochemical technologies to metal recovery from e-waste. It first outlines the electrochemical principles involved in metal extraction and separation, and then reviews established and emerging technologies for metal extraction, separation, purification, and recovery. Particular attention is given to their integration within hydrometallurgical flowsheets and to differences in technological maturity, selectivity, efficiency, and scalability. For example, industrial copper electrowinning typically requires approximately 1.8–2.5 kWh kg−1 Cu, providing a useful reference benchmark for evaluating secondary-feed applications. Overall, electrochemical technologies offer significant potential to reduce reagent consumption and improve metal selectivity, although their industrial implementation remains strongly dependent on feed composition, process integration, and robust operation under realistic conditions.