Extraction of Uranium(VI) and Plutonium(IV) by New Tri Alkylcarbamides. Issue 3 (16th April 2022)

• Record Type: Journal Article
• Authors: Berger, Clémence; Moreau, Ella; Marie, Cécile; Guillaumont, Dominique; Beillard, Audrey; Berthon, Laurence
• Is Part Of: Solvent extraction and ion exchange. Volume 40:Issue 3(2022)
• Page Start: 290
• Page End: 311
• Publication Date: 2022-04-16
• Subjects: Liquid-liquid extraction -- uranium -- plutonium -- alkylcarbamide; Solvent extraction -- Periodicals; Ion exchange -- Periodicals; 660.284248
• DOI: 10.1080/07366299.2021.1920167
• Languages: English
• ISSNs: 0736-6299

Abstract

ABSTRACT: The use of tri-alkylcarbamides (TrAC) as novel extractants for the separation of uranium(VI) and plutonium(IV) by solvent extraction from spent nuclear fuels is investigated. The comparison between extraction properties of different tri-alkylcarbamides and tetra-alkylcarbamides indicates their higher ability to co-extract uranium(VI) and plutonium(IV). Moreover, tri-alkylcarbamides present very high separation factors SFU/Pu (up to 100) at lower nitric acid concentration showing that they are good candidates for U(VI)/Pu(IV) separation without redox chemistry. The addition of branched 2-ethylhexyl chains induces a decrease of distribution ratios and U/Pu separation factor. Due to the formation of intermolecular hydrogen bond between carbonyl and -NH functions, the viscosity of tri-alkylcarbamides is higher compared to tetra-alkylcarbamides. Nevertheless, the introduction of branched alkyl chains decreases the viscosity of the solvent and increases the limit organic concentration (LOC) for uranium(VI), preventing from third phase formation.