Yamin Dong

The synergistic extraction of heavy rare earth elements using EHEHP-type and BTMPP-type functional ionic liquids

As for the supply risk and application in clean energy, heavy rare earth elements (HREEs) are more important than light rare earth elements (LREEs). In this paper, the synergistic extraction based on 2-ethyl(hexyl) phosphate mono-2-ethylhexyl ester and the bis(2,4,4-trimethylpentyl) phosphate acid base coupling of bifunctional ionic liquids (ABC-BILs) for HREEs separation is reported. Extractabilities of the novel systems were better than those using mixed 2-ethyl(hexyl) phosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) and bis(2,4,4-trimethylpentyl) phosphinic acid (HBTMPP). Also, the stripping property of the ABC-BIL based synergistic extraction system for HREE was better than that of mixed HEH[EHP] and HBTMPP. Advantages of the novel synergistic system based on ABC-BILs have revealed potential applications for the HREEs separation industry.

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.