The Sustainable and Efficient Ionic Liquid-Type Saponification Strategy for Rare Earth Separation Processing

Abstract

For the development of sustainable and efficient separation technology for rare earth elements (REEs), the ionic liquid-type saponification strategy is first put forward in this paper. The extraction mechanism of [trihexyl(tetradecyl)phosphonium][sec-octylphenoxy acetate] ( [P 6,6,6,14 ][SOPAA]) prepared by ionic liquid-type saponification for Y(III) was indicated to be ion association. The mechanism contributes to avoiding the numerous saponification procedures and resulting saponification wastewater in the REE separation industry. Load capacity and stripping properties of [P 6,6,6,14 ][SOPAA] reveal advantages over its precursory sec-octylphenoxy acetic acid (HSOPAA). Extractability and selectivity of [P 6,6,6,14 ][SOPAA] for Y(III) are pronouncedly better than those of HSOPAA. Multistage extraction using functional ionic liquid as extractant for different REE separations is developed. After five stages of extraction sections and four stages of scrubbing sections, Lu(III) was successfully separated from Y(III) using the fractional extraction process. Moreover, stripping by distilled water was achieved in ionic liquid-based extraction for REE, which contributes to decrease the consumption of acid to a considerable extent.

Recovery of boron from brines with high magnesium content by solvent extraction using aliphatic alcohol

“…Reducing the water entrainment in the extraction process could signicantly improve the phase separation and eliminate the occurrence of emulsication problem. 29,30 Three alcohols marked c, g and i in Table 2 all have branched chains with different carbon chain numbers. The extraction efficiencies of all these three alcohols were more than 80% with isooctanol being the highest of 84.46% (Fig.…”

Enhanced Homogeneous Liquid–Liquid Extraction for the Selective Recovery of Sc(III) by Novel UCST-Type Ionic Liquids

“…Ionic liquids (ILs), as the organic molten salts, have been emerging as the green solvents for liquid–liquid extraction and gas absorption at an ambient temperature, which is ascribed to their low melting points, negligible volatility, high thermal stability, and nonflammability. − So far, exploring the novel IL-based extractants, especially the functionalized ILs, is highly desirable for the extraction of REEs due to their superior extractability and environmental-friendly nature compared to organic extractants. − Although IL-based extractants exhibit the remarkable extraction capacities, the high viscosity of ILs still makes the extraction process undergo sluggish kinetics and thus needs a longer equilibrium time. , In light of these facts, developing the homogeneous liquid–liquid extraction system offers a promising strategy to address the aforementioned obstacles, ultimately enhancing the extraction efficiency and extraction rate in REE recovery.…”

Methods of Ensuring Energy Security with the Use of Hard Coal—The Case of Poland

“…On the other hand, introducing ELM and HFLM membranes and their modification (multistage process, complexation with EDTA or DTPA, and introduction of IIPs) made it possible to achieve 100% recovery of REEs [48][49][50][51]. In turn, the use of appropriately selected ionic liquids and multistage extraction allows for the enrichment of REEs above 95% [52,53]. They could be an alternative for conventionally used organic extractants because of their excellent extractability and safety for the natural environment.…”