Rare earth recovery from end-of-life motors employing green chemistry design principles

Abstract

This manuscript describes the development of an efficient process for the recovery of rare earth elements from materials mixtures such as in motors with a recovery rate of >80%. While heat treatment is required for processing, all other steps can be performed at room temperature, thus resulting in a process designed for energy efficiency. Selective dissolution enables efficient separation of steel and copper by taking advantage of the different reduction potentials of the materials in the mixture, while selective precipitation of RE salts is the key for obtaining pure RE products. Overall, the established process applies green chemistry principles for designing a hydrometallurgical process.