Recovery of Rare Earth Elements (REEs) From Different Sources of E-Waste and Their Potential Applications: A Focused Review

The rapid use of electrical and electronic devices due to their wide applications in various fields produces a large amount of e-waste (electronic waste) in the modern world. To overcome this problem, there is a need to recycle the used product into useful products from e-waste. Therefore, this approach is essential for the development of advanced technologies for the recovery and separation of REEs (rare earth elements) from e-waste. Here, REEs are sometimes referred to as the “vitamins” of the modern industry. E-waste can contribute significantly to REE pollution since it is frequently handled hazardously and contains high amounts of REEs. Apart from the harmful effects on the environment, these wastes also destroy precious materials such as gold, silver, copper, platinum, palladium, and rare earth elements. Every year, 50 million tons of e-waste is generated worldwide. A large amount of e-waste goes to waste as only 20% of it is handled properly worldwide. The various approaches, including bioleaching, biosorption, siderophores, pyrometallurgical, and hydrometallurgical processes, have been reported in numerous studies on the recovery and separation of rare earth elements (REEs) from electronic waste. This review paper provides an overview of the introduction, characteristics, sources, and applications of clean and green energy technologies. The current pathways for REEs production and recovery point out significant deficiencies in methods currently in use and emphasise areas where multidisciplinary research may lead to more practical solutions. A summary also provides the impact of e-waste on health and the environment. The challenges, research gap, and future directions and suggestions are reported at the end of this review paper.