Zeyuan Zhao

A separation processing for industrial rare earth feed solution by phosphonium ionic liquid type saponification strategy

Abstract A novel ionic liquid type saponification processing based on quaternary phosphonium type bifunctional IL was developed for yttrium separation from ion-adsorbed rare earth deposit. The extractabilities of ([trihexyl(tetradecyl)phosphonium][sec-octylphenoxy acetate] ([P 6,6,6,14 ][SOPAA]) were pronouncedly higher than those of sec-octylphenoxy acetic acid (HSOPAA), a mixture of HSOPAA and [P 6,6,6,14 ]Cl for rare earth elements (REEs). The ion association extraction mechanism contributed to avoiding the numerous saponification procedures using alkali and resulting in saponification wastewater. After 13 stages of extraction and 6 stages of scrubbing sections, the Y(III) was successfully separated from industrial heavy RREs feed, the purity of Y(III) in raffinate was approximately to be 98.9%. Stripping by distilled water was effectively achieved for REEs, which contributed to the decreased consumption of acid to a considerable extent.