Research progress of membrane technology for the separation of rare earth elements

Rare earth metals are regards as the essential strategic resources in China due to the unique roles in high-precision products. The separation and purification of rare earth elements is particularly important in order to satisfy the high purity criterion of products. Membrane separation technology is a highly efficient, low power consuming and environmental-friendly separation method, which can be widely used in extensive fields. In addition, their application in rare earth metal separation can efficiently improve the separation properties and greatly decrease the serious environment pollutions caused by the rare earth separation and its related industries. Hence, the scientific researches on these issues are highly crucial but still facing challenges. In this review, three kinds of membrane separation strategies, including ion imprinted membrane, polymer inclusion membrane and liquid membrane, were systematically introduced. Moreover, the preparation methods and separation properties of membrane materials were summarized, and the characteristics, advantages and disadvantages of subdivision types of membrane technology were discussed and compared. Furthermore, Ion imprinted membrane exhibited the great advantages in separation selectivity, but further improvement of adsorption capacity was highly needed, which was also the research focus of membrane separation technology in the next few years. Polymer inclusion membrane and liquid membrane separation technology showed the great potentials in the rare earth separation using membrane technology in the industrial application because it can flexibly adjust the type and quantity of active sites targeting at rare earth separation according to the type and amount of extractant. © 2022 Chemical Industry Press. All rights reserved.