Strategies and options for the sustainable recovery of rare earth elements from electrical and electronic waste

Rare earth elements (REEs) are among the important elements in various high-technological appliances globally. Recently, the recovery of REEs from the waste electrical and electronic equipment (WEEE) has gained significant interest for the sustainability of global electrical and electronic industrial markets. The fast-evolving and rapid changing of technology has made many of these hi-tech equipment become obsolete with high disposal rates. Rising concerns over the depletion of REE sources have led to the need to extract and recover the REEs from WEEE. However, many studies still need to be carried out to optimize the recovery processes of the REEs in terms of the extraction methods employed and to minimize the environmental impact and hazard towards the flora and fauna. This review outlines the various REEs available in a wide range of electrical and electronic equipment, the various types of REE recovery methods, as well as their environmental impacts. The future perspectives and research directions in terms of the circular economy, policy and regulatory framework and research roadmap for REE recovery from WEEE are also discussed.