A synergistic extraction strategy by [N1888][SOPAA] and Cyphos IL 104 for heavy rare earth elements separation

• Published in: Separation and purification technology Vol. 174; pp. 474 - 481
• Main Authors: Ma, Li, Zhao, Zeyuan, Dong, Yamin, Sun, Xiaoqi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2017
• Subjects: Acetates; Acetic acid; Coefficients; Extraction; Ionic liquid; Ionic liquids; Rare earth; Rare earth elements; Separation; Slopes; Synergistic extraction; Separation; Rare earth; Synergistic extraction; Ionic liquid
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2016.10.046

[Display omitted] •Rare earth extraction using [N1888][SOPAA] and Cyphos IL 104 was studied.•The bifunctional ILs revealed pronouncedly synergistic effect.•An ion association extraction mechanism was proposed.•Loaded Lu(III) could be full stripped using hydrochloric acid.•The synergistic system was effective for the separation of heavy rare earth. Synergistic extraction of trivalent rare earth element (REE) from hydrochloride solution using mixtures of methyltrioctylammonium sec-octylphenoxy acetate ([N1888][SOPAA]) and trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate ([P66614][BTMPP], Cyphos IL 104) has been investigated. Extraction mechanism of the ionic liquid (IL) extractants for Lu(III) was indicated to be ion association using slope analysis method and Infra Red (IR) spectra. The IL based extraction system revealed pronouncedly synergistic effects in the extraction of Lu(III). The largest synergistic enhancement coefficient from different mole fractions of [N1888][SOPAA] and [P66614][BTMPP] reached 40.47, which was much larger than that of 3.05 from sec-octylphenoxy acetic acid (HSOPAA, CA-12) and bis(2,4,4-trimethylpentyl)phosphinic acid (HBTMPP, Cyanex272) under the same conditions. The loaded Lu(III) could be full stripped using hydrochloric acid. This paper reveals a potential application in heavy REE separation.