Molten salt/liquid metal extraction: Electrochemical behaviors and thermodynamics properties of La, Pr, U and separation factors of La/U and Pr/U couples in liquid gallium cathode. (April 2022)

• Record Type: Journal Article
• Authors: Xu, Hengbin; Zhang, Wei; Wang, Changshui; Yang, Mingshuai; Yan, Taihong; Yan, Yongde; Zhang, Milin
• Is Part Of: Applied radiation and isotopes. Volume 182(2022)
• Publication Date: 2022-04
• Subjects: Thermodynamic properties -- Separation factor -- Lanthanides -- Uranium -- Liquid Ga; Radiology -- Periodicals; Radiation -- Industrial applications -- Periodicals; Nuclear chemistry -- Periodicals; Internet resource; Periodical; 660.298
• DOI: 10.1016/j.apradiso.2022.110149
• Languages: English
• ISSNs: 0969-8043

Abstract

Abstract: The electrochemical behavior of lanthanides (La, Pr) and actinide (U) on inert W and liquid Ga electrodes in LiCl–KCl molten salt as well as their related thermodynamic properties were experimentally determined for further Lns/Ans separation. The results indicate that the reductions of La 3+ and Pr 3+ in LiCl–KCl melts are both one-step process with three electrons exchanged, and the reactions are quasi-reversible processes at low scan rate. Temperature dependencies of apparent standard redox potentials of La(Ga), Pr(Ga) and U(Ga) alloys were determined by open-circuit chronopotentiometry versus Cl - /Cl2 reference electrode. The activity and activity coefficients of lanthanum, praseodymium and uranium on the liquid Ga electrode in the temperature interval 723–813 K were calculated. The separation factors for La/U and Pr/U on the liquid Ga electrode in the molten salt were determined by l o g θ U / L a = − 10.39 + 11440.69 T ± 0.0125 and l o g θ U / P r = − 5.84 + 7763.27 T ± 0.07 . The separation factors of La/U and Pr/U on the liquid Ga electrode indicate that lower temperature should be more effective for separating uranium. Highlights: 1. Electrochemical properties of La, Pr and U were determined on liquid Ga and W wire. 2. Thermodynamic of La, Pr and U were determined in La(Ga), Pr(Ga) and U(Ga) alloys. 3. Effect of temperature (723–813 K) on separation factors of La/U, Pr/U were studied. 4. The lower temperature should be more effective for separating uranium.