Advances in Bioleaching of Rare Earth Elements from Electronic Wastes

Bioleaching rare earth elements (REEs) from low-grade resources, including wastes, is a promising green technology. The microorganisms used in bioleaching mainly include bacteria and fungi. Bioleaching REEs involves different interaction mechanisms between microorganisms and REEs. Bioleaching REEs from urban mines such as various electronic wastes has become a hotspot in research. Bioleaching of copper cores has been practiced at huge commercial scales. Thus, bioleaching of REEs has the potential to be commercialized. It will become an economically viable method soon. This work mainly reviews the technology of bioleaching REEs from electronic wastes, including the present situations and applications of REEs resources, various REEs recovery technologies, recovering REEs from WEEE (waste electrical and electronic equipment) using bioleaching, types of microbes and leaching mechanisms, and post-leaching/bioleaching process. In order to make bioleaching of REEs practical, more research is needed, especially in the development of new microbial strains and bioreactor technology.