Solvent extraction of rare-earth ions based on functionalized ionic liquids

► Novel DEHP-type ILs as ionic extractants are miscible with [C6mim][NTF2]. ► DEHP-type extractants revealing higher extractabilities for REEs in [C6mim][NTF2]. ► DEHP-type extractants demonstrate better selectivities for REEs than HDEHP in [C6mim][NTF2]. ► High performance of comprehensive IL-based extraction system is first mentioned. ► REEs in IL-based TALSPEAK can be effectively stripped from extractant by nitric acid.