Guerinoni, E.; Dourdain, S.; Dumas, T.; Arrachart, G.; Giusti, F.; Lu, Z.; Solari, P.-L.; Pellet-Rostaing, S. Enhancing Uranium Extraction Efficiency Using Protonated Amines and Quaternary Ammoniums-Based Ionic Liquids: Mechanistic Insights and Nonlinearities Analysis. Separations2023, 10, 509.
Guerinoni, E.; Dourdain, S.; Dumas, T.; Arrachart, G.; Giusti, F.; Lu, Z.; Solari, P.-L.; Pellet-Rostaing, S. Enhancing Uranium Extraction Efficiency Using Protonated Amines and Quaternary Ammoniums-Based Ionic Liquids: Mechanistic Insights and Nonlinearities Analysis. Separations 2023, 10, 509.
Guerinoni, E.; Dourdain, S.; Dumas, T.; Arrachart, G.; Giusti, F.; Lu, Z.; Solari, P.-L.; Pellet-Rostaing, S. Enhancing Uranium Extraction Efficiency Using Protonated Amines and Quaternary Ammoniums-Based Ionic Liquids: Mechanistic Insights and Nonlinearities Analysis. Separations2023, 10, 509.
Guerinoni, E.; Dourdain, S.; Dumas, T.; Arrachart, G.; Giusti, F.; Lu, Z.; Solari, P.-L.; Pellet-Rostaing, S. Enhancing Uranium Extraction Efficiency Using Protonated Amines and Quaternary Ammoniums-Based Ionic Liquids: Mechanistic Insights and Nonlinearities Analysis. Separations 2023, 10, 509.
Abstract
This study investigates uranium solvent extraction under AMEX process conditions. The use of pure extractants without diluents or phase modifiers allows not only to reduce the use of volatile organic compounds, but also to provide higher extraction yields without third phase formation. Pure extractants are protonated amines or quaternary ammoniums with suitable counter ion, which act at the interface between ion pairs and protic ionic liquids. The mixture of sulfates anion (SO42-) and bis(trifluoromethanesulfonyl)imide anion (NTf2-) revealed unexpected nonlinear extraction behaviors, which appear highly important to rationalize for optimized application. Spectroscopic analysis (NMR, UV-vis, FT-IR, and EXAFS) showed that uranium extraction occurs via protonated amine and three sulphates. Nonlinear extraction could further be interpreted by considering water and acid transfer between the two phases: at lower sulphate ratios, the release of acid from the organic phase into the aqueous phase was shown to influence the number of protonated amines in the organic phase, affecting uranium extraction before its enhancement. Furthermore, the extraction loss at higher sulphate ratios, was assigned to the destabilization of bidentate uranium-sulphate complexes due to a competition between water and sulphates.
Chemistry and Materials Science, Analytical Chemistry
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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