Analysis of the Separation Processes of Rare-Earth Elements in the Cascade of Mixing and Settle Extractors by Liquid–Liquid Chromatography Methods

Liquid extraction methods are currently used for the separation of rare-earth elements (REEs) on an industrial scale, usually implemented in complex multistage systems consisting of multiple mixing and settling extractors. This work is devoted to a theoretical analysis of the processes of separation of REEs in a cascade of mixing–settling extractors in the liquid–liquid chromatography mode. Due to the simplicity of the scheme and the possibility of carrying out separation in one technological operation, the potential of using liquid–liquid chromatography methods for the separation and isolation of concentrated fractions of REEs from aqueous solutions in a cascade of mixing and settling extractors is demonstrated.