Homogeneous Liquid–Liquid Extraction of Metal Ions with a Functionalized Ionic Liquid

Abstract

Binary mixtures of the ionic liquid betainium bis(trifluoromethylsulfonyl)imide and water show an upper critical solution temperature. This solvent system has been used to extract metal ions by phase-transition extraction, using zwitterionic betaine as extractant. The system is efficient for the extraction of trivalent rare-earth, indium and gallium ions. This new type of metal extraction system avoids problems associated with the use of viscous ionic liquids, namely, the difficulty of intense mixing of the aqueous and ionic liquid phases by stirring.

Use of extraction chromatography in the recycling of critical metals from thin film leach solutions

“…that can be adjusted by varying either the anion or the cation to permit their use in a wide range of applications. In particular they have been used as solvents for the extraction, separation and purification of metals and metal oxides [21][22][23], including solubilising and separating trivalent RE oxides [24][25][26][27][28][29][30]. This includes the use of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C4mim][Tf2N] in a liquid-liquid extraction process [30] for the recovery of RE elements from waste fluorescent lamp phosphor powders in which the RE elements were extracted with N,N-dioctyldiglycolamic acid (DODGAA) dissolved in the ionic liquid.…”

Interactions between trivalent rare earth oxides and mixed [Hbet][Tf2N]:H2O systems in the development of a one-step process for the separation of light from heavy rare earth elements

“…that can be adjusted by varying either the anion or the cation to achieve applications that are credible alternatives to conventional solvents for the extraction, separation and purification of metals and metal oxides [5][6][7][8][9][10]. A series of publications from Binneman's and Nockemann's research groups [6,[11][12][13][14][15][16] using betaine as an extractant [12,13], and in the recovery of europium (Eu) and yttrium (Y) from lamp phosphor waste powders [14]. The solubility of the rare earth oxides in…”

Regeneration of the ionic liquid tetraoctylammonium oleate after metal extraction

“…It has already been proven that some ILs present excellent metal extraction efficiencies. [2][3][4][5][6] Recently, non-fluorinated fatty acid based ILs were synthesized in the search for biocompatible, non-toxic metal selective ILs. 7 Oleic acid and linoleic acid were selected as anion due to their affinity towards metals combined with the voluminous and hydrophobic tetraalkylammonium cations to prevent the loss of the IL to the water phase.…”