Extraction mechanism of rare earths from chloride acidic solution with ammonium-bifunctionalized ionic liquid extractants

Abstract

A series of ammonium-bifunctionalized ionic liquid extractants (ammonium-Bif-ILEs) combined with a number of anions, including carboxylic acids and 1,3-diketonates, have been prepared and studied in this report. Their extraction behavior and properties toward rare earth ions (REs(III)) are systematically investigated in chloride media as a function of important parameters such as aqueous phase pH, salting-out agent concentrations, and extraction temperature. The separation performance of ammonium-Bif-ILEs toward REs(III) are systematically discussed. The results demonstrate that ammonium-Bif-ILEs have a synergistic effect between the cation and anions in separation of REs(III). The influences of different anions on separation factor () values are further studied. By comparison, ammonium-Bif-ILEs containing 1,3-diketonates have more potential applications in La(III)/RE(III) separation than those containing carboxylic acids. ammonium-bifunctional ionic liquids, separation, rare earths Citation:Yang HL, Chen J, Wang W, Cui HM, Liu WG, Liu Y. Extraction mechanism of rare earths from chloride acidic solution with ammonium-bifunctionalized ionic liquid extractants.

Extraction kinetics of mixed rare earth elements with bifunctional ionic liquid using a constant interfacial area cell

“…Other advantages, such as avoiding saponication wastewater from the application of acidic extractants, low acidity for extraction and good interfacial phenomena, have emerged. 12,13 (2,6-Dimethylheptyl) phenoxy acetic acid (HPOAA) and [methyltrioctyl ammonium (N 1888 )] [POAA] have been synthesized in this lab recently. The former was used for the separation of high-purity yttrium from ionabsorbed rare earth ore. [14][15][16] The later was used for the development of sustainable yttrium separation process from heavy rare earth enrichments.…”

Extraction Mechanism of Lithium from the Alkali Solution with Diketonate-Based Ionic Liquid Extractants

“…Four diketonate-based functional ILs (Table ), i.e., trialkylmethylammonium benzoyltrifluoroacetone ([A336]­BTA), trialkylmethylammonium 2-thenoyl-trifluoroacetone ([A336]­TTA), trialkylmethylammonium 4,4,4-trifluoro-1-( p -tolyl)-1,3-butanedione ([A336]­TPBA), and trialkylmethylammonium 4,4,4-trifluoro-1-(2-furyl)-1,3-butanedione ([A336]­TFBA), were synthesized according to a published method. , First, the chloride ions in [A336]Cl were exchanged into OH – ions by an anion exchange resin. Then, the obtained [A336]­OH was further reacted with the 1,3-diketone compound for about 8 h. Subsequently, the organic phase was separated and washed three times by deionized water.…”

“…The quality of samples was measured using an analytical balance (Mettler Toledo ME204) with a precision of ±0.1 mg. 4,4,4-trifluoro-1-(2-furyl)-1,3-butanedione ([A336]TFBA), were synthesized according to a published method. 33,34 First, the chloride ions in [A336]Cl were exchanged into OH − ions by an anion exchange resin. Then, the obtained [A336]OH was further reacted with the 1,3diketone compound for about 8 h. Subsequently, the organic phase was separated and washed three times by deionized water.…”

A New Extraction System Based on Isopropyl Salicylate and Trioctylphosphine Oxide for Separating Alkali Metals

“…Mixtures of 1,3-diketones and neutral extractants, namely tributyl phosphate (TBP) and trioctylphosphine oxide (TOPO), quantitatively extract lithium from alkaline solutions containing high excess of Na + , K + [ 15 , 16 , 17 , 18 ]. The degree of alkali cations extraction with such mixtures reasonably decreases in the series Li + > Na + > K + with the increase of the ionic radii of alkali ions [ 15 , 19 , 20 , 21 , 22 , 23 , 24 ]. Enol form of 1,3-diketone chelate the lithium ion through the cation-exchange mechanism with the formation of a six-membered metallacycle and subsequent coordination with electron-donor molecules, such as TOPO [ 25 ] ( Scheme 1 ).…”