Rare earth elements resources and beneficiation: A review

Rare earth elements (REEs) are mineral resources of crucial strategic significance. In recent years, the demand for REEs in the military, magnetic materials, energy, and other emerging industries has increased with the development of new technologies. In this paper, a general overview of rare earth resources and the mineralogical characteristics of rare earth deposits around the world is provided. Moreover, the beneficiation methods of different types of rare earth minerals (REMs), and the reaction mechanism of different beneficiation reagents with minerals are summarized. REMs are typically separated by gravity separation, magnetic separation, electrostatic separation, flotation and chemical leaching, among which flotation and chemical leaching are the major methods for treating mineral-type and ion adsorption-type REMs, respectively. In addition, several process flows for rare earth ores separation in several typical beneficiation plants are introduced. On this basis, future developments and research directions of beneficiation reagents, separation technologies and related industries are presented. This provides a comprehensive reference for research on rare earth resources and lays the foundation for their efficient utilization and comprehensive recovery.