Acid Leaching of Rare Earth Elements Present in Waste Electrical and Electronic Equipment: A Brief Review

The accelerated expansion of the use of electronic products has generated large amounts of Waste Electrical and Electronic Equipment (WEEE), which makes the use of management strategies based on Circular Economy (CE) essential. In this sense, the recycling of these residues is of great interest due to the presence of metals with high added value, such as Rare Earth Elements (REE). Given the above, this review aims to elucidate issues related to the management and processing of WEEE and to evaluate the main parameters that influence the leaching step of REE present in these wastes. From the critical analysis of the bibliographic survey, it was noted that fluorescent lamps, cathode-ray tubes, NbFeB magnets and NiMH batteries are widely studied, with the objective of recovering REE. However, considerable variations were observed with regard to the content of metals present in each of these residues. In short, it is important that the recovery of these metals is studied, not only due to economic aspects, but also aiming at environmentally sustainable recycling.