Hydrometallurgical recycling strategies for recovery of rare earth elements from consumer electronic scraps: a review

Abstract

The global demand for rare earth elements (REEs) for use in hi-tech applications is constantly rising, yet their supply is a matter of concern given high rates of disposal. However, urban waste such as consumer electronic scrap (CE-Scrap) has remarkable potential to come to the rescue and meet this growing demand, in line with circular economy principles. Notwithstanding this, globally, their commercial extraction and recovery are yet to be adopted, as <1% of REEs are obtained from recycled CE-Scrap, with the rest removed from the materials cycle. Considering the economic importance and industrial applicability of REEs, the current status of the potential CE-Scrap resources for REEs recycling is presented herein. The summarized availability of all REEs, their mode of occurrence and the prospects of relevant recycling processes, typically by the hydrometallurgical route, are discussed. The feasibility of using established REE extraction and recovery technologies is discussed concerning CE-Scrap such as spent fluorescent lamps, spent NiMH hybrid batteries, computer monitor scrap, and scrap NdFeB magnets. Furthermore, the pros and cons associated with their separation are discussed along with the future directions of research and policies to be envisaged in urban resource recycling. (c) 2021 Society of Chemical Industry (SCI).