Ligand free extraction of tri-, tetra-, and hexa-valent actinide ions from aqueous hydrochloric acid medium using task specific ionic liquids

IF 5.3 2区化学 Q2 CHEMISTRY, PHYSICAL Journal of Molecular Liquids Pub Date : 2025-03-09 DOI:10.1016/j.molliq.2025.127324

Surekha D. Chowta , Arijit Sengupta , G. Sugilal , Prasanta K. Mohapatra

{"title":"Ligand free extraction of tri-, tetra-, and hexa-valent actinide ions from aqueous hydrochloric acid medium using task specific ionic liquids","authors":"Surekha D. Chowta , Arijit Sengupta , G. Sugilal , Prasanta K. Mohapatra","doi":"10.1016/j.molliq.2025.127324","DOIUrl":null,"url":null,"abstract":"<div><div>The present manuscript demonstrates the ligand free extraction of tetra-, hexa- and tri-valent actinides (Pu4+, UO22+ and Am3+) from hydrochloric acid medium using the ionic liquids, n-butyl trimethyl bis(trifluoromethylsulfonyl)imide (BuMe3N•NTf2); methyl-tri-n-butyl ammonium bis(trifluoromethylsulfonyl)imide (Bu3MeN•NTf2) and tri-n-hexyl tetradecyl phosphonium bis (2,4,4) trimethyl-n-pentylphosphinate ((C6)3C14P.(C1)3C5POO). The observed trend in the extraction of the actinides was: DPu > DU > DAm for a particular ionic liquid; while for a particular actinide the observed trend in its extraction was: (C6)3C14P.(C1)3C5POO) > BuMe3N•NTf2 > Bu3MeN•NTf2. The extraction of UO22+ and Pu4+ from 7 M HCl feed was found to proceed via the anionic chloro complexes, which were part of the following extracted species: <math><mrow><msub><mrow><mo>(</mo><msub><mrow><mi>B</mi><mi>u</mi></mrow><mn>3</mn></msub><mi>M</mi><mi>e</mi><mi>N</mi><mo>)</mo></mrow><mn>2</mn></msub><mrow><mfenced><mrow><mi>U</mi><msub><mi>O</mi><mn>2</mn></msub><msub><mrow><mi>C</mi><mi>l</mi></mrow><mn>4</mn></msub></mrow></mfenced></mrow></mrow></math> and <math><mrow><msub><mrow><msub><mrow><mo>(</mo><msub><mrow><mi>B</mi><mi>u</mi></mrow><mn>3</mn></msub><mi>M</mi><mi>e</mi><mi>N</mi><mo>)</mo></mrow><mn>2</mn></msub><mrow><mo>)</mo></mrow></mrow><mn>2</mn></msub><mrow><mfenced><mrow><mi>P</mi><mi>u</mi><msub><mrow><mi>C</mi><mi>l</mi></mrow><mn>6</mn></msub></mrow></mfenced></mrow></mrow></math>; <math><mrow><msub><mrow><mo>(</mo><msub><mrow><mi>M</mi><mi>e</mi></mrow><mn>3</mn></msub><mi>B</mi><mi>u</mi><mi>N</mi><mo>)</mo></mrow><mn>2</mn></msub><mrow><mfenced><mrow><mi>U</mi><msub><mi>O</mi><mn>2</mn></msub><msub><mrow><mi>C</mi><mi>l</mi></mrow><mn>4</mn></msub></mrow></mfenced></mrow></mrow></math> and <math><mrow><msub><mrow><msub><mrow><mo>(</mo><msub><mrow><mi>M</mi><mi>e</mi></mrow><mn>3</mn></msub><mi>B</mi><mi>u</mi><mi>N</mi><mo>)</mo></mrow><mn>2</mn></msub><mrow><mo>)</mo></mrow></mrow><mn>2</mn></msub><mrow><mfenced><mrow><mi>P</mi><mi>u</mi><msub><mrow><mi>C</mi><mi>l</mi></mrow><mn>6</mn></msub></mrow></mfenced></mrow></mrow></math>; <math><mrow><msub><mrow><mo>(</mo><msub><mrow><mi>H</mi><mi>e</mi><mi>x</mi></mrow><mn>3</mn></msub><mrow><mfenced><mrow><mi>T</mi><mi>e</mi><mi>t</mi><mi>r</mi><mi>a</mi><mi>d</mi><mi>e</mi><mi>c</mi><mi>y</mi><mi>l</mi></mrow></mfenced></mrow><mi>P</mi><mo>)</mo></mrow><mn>2</mn></msub><mrow><mfenced><mrow><mi>U</mi><msub><mi>O</mi><mn>2</mn></msub><msub><mrow><mi>C</mi><mi>l</mi></mrow><mn>4</mn></msub></mrow></mfenced></mrow></mrow></math> and <math><mrow><msub><mrow><mo>(</mo><msub><mrow><mi>H</mi><mi>e</mi><mi>x</mi></mrow><mn>3</mn></msub><mrow><mfenced><mrow><mi>T</mi><mi>e</mi><mi>t</mi><mi>r</mi><mi>a</mi><mi>d</mi><mi>e</mi><mi>c</mi><mi>y</mi><mi>l</mi></mrow></mfenced></mrow><mi>P</mi><mo>)</mo></mrow><mn>2</mn></msub><mrow><mfenced><mrow><mi>P</mi><mi>u</mi><msub><mrow><mi>C</mi><mi>l</mi></mrow><mn>6</mn></msub></mrow></mfenced></mrow></mrow></math>. The NTf2- anion was found to be exchanged from the ionic liquid phase to aqueous phase conforming to an 'anion exchange' mechanism. In the case of Am3+, the extraction predominantly proceeded via a 'solvation' mechanism with 1:1 Am-ionic liquid stoichiometry. The maximum separation factor for Pu over U was estimated as ∼3.0 (βPu/U) at 8 M HCl; while the same for plutonium over americium was 6.5 (βPu/Am) for Bu3MeN.NTf2; those for Me3BuN.NTf2 and (C6)3C14P.(C1)3C5POO were estimated as 2.6 (βPu/U), 14 (βPu/Am) and 1.8 (βPu/U), 25 (βPu/Am), respectively. The extraction processes were found to be spontaneous and exothermic in nature. Complexants viz. 0.5 M sodium carbonate, oxalic acid and EDTA were found to be successful in back extraction of more than 90 % U, Pu and Am, respectively from the loaded ionic liquid phase in a single contact. These solvent systems exhibited moderate radiolytic stability upto 500 kGy of γ ray exposure.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"427 ","pages":"Article 127324"},"PeriodicalIF":5.3000,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Molecular Liquids","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S016773222500491X","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}

引用次数: 0

Abstract

The present manuscript demonstrates the ligand free extraction of tetra-, hexa- and tri-valent actinides (Pu⁴⁺, UO₂²⁺ and Am³⁺) from hydrochloric acid medium using the ionic liquids, n-butyl trimethyl bis(trifluoromethylsulfonyl)imide (BuMe₃N•NTf₂); methyl-tri-n-butyl ammonium bis(trifluoromethylsulfonyl)imide (Bu₃MeN•NTf₂) and tri-n-hexyl tetradecyl phosphonium bis (2,4,4) trimethyl-n-pentylphosphinate ((C₆)₃C₁₄P.(C₁)₃C₅POO). The observed trend in the extraction of the actinides was: D_Pu > D_U > D_Am for a particular ionic liquid; while for a particular actinide the observed trend in its extraction was: (C₆)₃C₁₄P.(C₁)₃C₅POO) > BuMe₃N•NTf₂ > Bu₃MeN•NTf₂. The extraction of UO₂²⁺ and Pu⁴⁺ from 7 M HCl feed was found to proceed via the anionic chloro complexes, which were part of the following extracted species:

{({B u}_{3} M e N)}_{2} (U O_{2} {C l}_{4})

and

{{({B u}_{3} M e N)}_{2})}_{2} (P u {C l}_{6})

;

{({M e}_{3} B u N)}_{2} (U O_{2} {C l}_{4})

and

{{({M e}_{3} B u N)}_{2})}_{2} (P u {C l}_{6})

;

{({H e x}_{3} (T e t r a d e c y l) P)}_{2} (U O_{2} {C l}_{4})

and

{({H e x}_{3} (T e t r a d e c y l) P)}_{2} (P u {C l}_{6})

. The NTf₂^- anion was found to be exchanged from the ionic liquid phase to aqueous phase conforming to an 'anion exchange' mechanism. In the case of Am³⁺, the extraction predominantly proceeded via a 'solvation' mechanism with 1:1 Am-ionic liquid stoichiometry. The maximum separation factor for Pu over U was estimated as ∼3.0 (β_Pu/U) at 8 M HCl; while the same for plutonium over americium was 6.5 (β_Pu/Am) for Bu₃MeN.NTf₂; those for Me₃BuN.NTf₂ and (C₆)₃C₁₄P.(C₁)₃C₅POO were estimated as 2.6 (β_Pu/U), 14 (β_Pu/Am) and 1.8 (β_Pu/U), 25 (β_Pu/Am), respectively. The extraction processes were found to be spontaneous and exothermic in nature. Complexants viz. 0.5 M sodium carbonate, oxalic acid and EDTA were found to be successful in back extraction of more than 90 % U, Pu and Am, respectively from the loaded ionic liquid phase in a single contact. These solvent systems exhibited moderate radiolytic stability upto 500 kGy of γ ray exposure.

查看原文

微信好友朋友圈 QQ好友复制链接

本刊更多论文

本手稿展示了利用离子液体正丁基三甲基双(三氟甲基磺酰基)亚胺(BuMe3N-NTf2)从盐酸介质中无配体萃取四价、六价和三价锕系元素（Pu4+、UO22+ 和 Am3+）的过程；甲基-三正丁基双(三氟甲磺酰基)亚胺铵盐 (Bu3MeN-NTf2) 和三正己基十四烷基双(2,4,4) 三甲基-正戊基膦酸盐 ((C6)3C14P.(C1)3C5POO）。观察到的锕系元素萃取趋势是对于特定的离子液体，DPu > DU > DAm；而对于特定的锕系元素，观察到的萃取趋势是：(C6)3C14P.发现从 7 M HCl 进料中萃取 UO22+ 和 Pu4+ 是通过阴离子氯络合物进行的，这些络合物是以下萃取物的一部分：(Bu3MeN)2UO2Cl4 和 (Bu3MeN)2)2PuCl6; (Me3BuN)2UO2Cl4 和 (Me3BuN)2)2PuCl6; (Hex3TetradecylP)2UO2Cl4 和 (Hex3TetradecylP)2PuCl6。研究发现，NTf2- 阴离子从离子液体相交换到水相符合 "阴离子交换 "机制。在 Am3+ 的情况下，萃取主要通过 "溶解 "机制进行，Am-离子液体的化学计量为 1:1。在 8 M HCl 条件下，钚对铀的最大分离系数估计为 ∼ 3.0 (βPu/U)；而在 Bu3MeN.NTf2；Me3BuN.NTf2 和 (C6)3C14P.(C1)3C5POO 的估计值分别为 2.6 (βPu/U), 14 (βPu/Am) 和 1.8 (βPu/U), 25 (βPu/Am)。萃取过程为自发放热。络合剂（即 0.5 M 碳酸钠、草酸和乙二胺四乙酸）可在一次接触中成功地从负载离子液体相中萃取出超过 90% 的铀、钚和镅。在 500 kGy γ 射线照射下，这些溶剂系统表现出适度的放射性稳定性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文去求助

来源期刊

Journal of Molecular Liquids 化学-物理：原子、分子和化学物理

CiteScore

10.30

自引率

16.70%

发文量

2597

审稿时长

78 days

期刊介绍： The journal includes papers in the following areas: – Simple organic liquids and mixtures – Ionic liquids – Surfactant solutions (including micelles and vesicles) and liquid interfaces – Colloidal solutions and nanoparticles – Thermotropic and lyotropic liquid crystals – Ferrofluids – Water, aqueous solutions and other hydrogen-bonded liquids – Lubricants, polymer solutions and melts – Molten metals and salts – Phase transitions and critical phenomena in liquids and confined fluids – Self assembly in complex liquids.– Biomolecules in solution The emphasis is on the molecular (or microscopic) understanding of particular liquids or liquid systems, especially concerning structure, dynamics and intermolecular forces. The experimental techniques used may include: – Conventional spectroscopy (mid-IR and far-IR, Raman, NMR, etc.) – Non-linear optics and time resolved spectroscopy (psec, fsec, asec, ISRS, etc.) – Light scattering (Rayleigh, Brillouin, PCS, etc.) – Dielectric relaxation – X-ray and neutron scattering and diffraction. Experimental studies, computer simulations (MD or MC) and analytical theory will be considered for publication; papers just reporting experimental results that do not contribute to the understanding of the fundamentals of molecular and ionic liquids will not be accepted. Only papers of a non-routine nature and advancing the field will be considered for publication.