Reversed micelle synergistic extraction from phosphonium ionic liquid extractants in diluent for rare earth

Abstract

The first synergistic extraction between quaternary phosphonium type ionic liquid extractants in toluene for rare earth was reported in this article. There were two different ion-association mechanisms in the synergistic extraction system. The formed reversed micelles contributed to increase extractability of the synergistic extraction system to a considerable extent. On the one hand, million tons of saponification wastewater from acidic extractants may be avoided by developing the extraction system using bifunctional ionic liquid extractants. On the other hand, the novel synergistic extraction offers an effective strategy to increase the extractabilities of industrial extractants. This article reveals sustainable and efficient potentials for industrial rare earth separation.

Efficient Recovery of End-of-Life NdFeB Permanent Magnets by Selective Leaching with Deep Eutectic Solvents

“…One method is replacing the hazardous acids and organic solvents with ecologically friendly solvents, such as ionic liquids (ILs) or deep eutectic solvents (DESs), in the solvent extraction process. − For example, Riano and Binnemans used a IL, trihexyl­(tetradecyl)­phosphonium nitrate, as the organic phase to extract REEs from iron-free leachate of a NdFeB permanent magnet . In comparison to the traditional organic solvents, the ILs and DESs are green solvents with low volatility or biodegradable in nature, avoiding the large secondary chemical wastes. − The inorganic acid used in complete leaching could also be replaced by greener ILs or DESs to reduce the amounts of wastewaters. , Another method to improve the separation process is a process optimization, which replaces complete leaching with selective leaching. − Because the target metals are selectively leached from the solid materials, the solvent extraction procedure is not necessary for this method, which endows it with great strengths in compact and green processes. , The flowcharts of the solvent extraction and selective leaching processes are comparatively shown in Scheme .…”

Role of ionic liquids in the efficient transfer of lithium by Cyanex 923 in solvent extraction system

“…Ionic liquids (ILs) have gained considerable attention for metal ions separation in solvent extraction system owning to their superior characteristics such as low vapor pressure, nonflammable properties, and tunable structures . As an extracting agent, ILs can be manipulated through design of the cation and anions to improve the extraction efficiency and the selectivity of metal ions of interest . The hydrophobic character and negligible vapor pressure of certain ILs allow their use as solvents to replace traditional volatile molecular solvents .…”