{"title":"Activity Coefficients and Solubility of Uranium in Liquid-Metal Pb–Sn Alloys","authors":"A. V. Novoselova, V. V. Smolenski, A. L. Bovet","doi":"10.1134/S0036029525701289","DOIUrl":null,"url":null,"abstract":"<p><b>Abstract</b>—The equilibrium potentials of liquid-metal U–M alloys (where М = Pb, Pb–Sn, and Sn) are measured in a U(М)<sub>(dil)</sub>|NaCl–2CsCl–UCl<sub>3</sub>||NaCl–2CsCl|C<sub>(s)</sub>, Cl<sub>2(g)</sub> electrochemical cell using open-cercuit potentiometry. The electromotive force (emf) of a U|NaCl–2CsCl–UCl<sub>3</sub>|M + UM<sub><i>x</i></sub> galvanic cell, in which the liquid-metal alloy corresponds to the two-phase region and UM<sub><i>x</i></sub> is an intermetallic compound, is measured to determine uranium solubility in the alloys. The experiments are carried out in a molten NaCl–2CsCl eutectic under an inert gas atmosphere. Reagents containing no impurities of moisture, oxygen, and their compounds are used in the experiments. All the main procedures are carried out in a dry glove box. The NaCl–2CsCl–UCl<sub>3</sub> melts are prepared in two stages. A NaCl–2CsCl–UCl<sub>4</sub> melt is prepared first by the chlorination of metallic uranium with gaseous chlorine, and then the prepared electrolyte is stored in contact with uranium to form a NaCl–2CsCl–UCl<sub>3</sub> solution. Uranium alloys with low-melting metals are prepared prior to experiment by the electrolysis of the NaCl–2CsCl–UCl<sub>3</sub> melt. The electrolysis time corresponds to conditions of one-phase or two-phase region formation. The high-temperature filtration of saturated alloys through a porous quartz filter is used to determine the uranium concentration in an alloy containing no intermetallic compounds. The dependences of the activity coefficients of γ-U in lead, tin, and Pb–Sn bimetallic alloy are detected. The temperature dependences of the emf of the galvanic cell are approximated by straight lines, and the values of emf depend on the nature of the alloy components and decrease in the order Sn > Pb–Sn > Pb. The solubility of uranium in the U–Pb, U–Pb–Sn, and U–Sn alloys is determined. The solubility of uranium is found to be low and almost independent of the alloy nature.</p>","PeriodicalId":769,"journal":{"name":"Russian Metallurgy (Metally)","volume":"2025 2","pages":"395 - 399"},"PeriodicalIF":0.3000,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Russian Metallurgy (Metally)","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1134/S0036029525701289","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"METALLURGY & METALLURGICAL ENGINEERING","Score":null,"Total":0}
引用次数: 0
Abstract—The equilibrium potentials of liquid-metal U–M alloys (where М = Pb, Pb–Sn, and Sn) are measured in a U(М)(dil)|NaCl–2CsCl–UCl3||NaCl–2CsCl|C(s), Cl2(g) electrochemical cell using open-cercuit potentiometry. The electromotive force (emf) of a U|NaCl–2CsCl–UCl3|M + UMx galvanic cell, in which the liquid-metal alloy corresponds to the two-phase region and UMx is an intermetallic compound, is measured to determine uranium solubility in the alloys. The experiments are carried out in a molten NaCl–2CsCl eutectic under an inert gas atmosphere. Reagents containing no impurities of moisture, oxygen, and their compounds are used in the experiments. All the main procedures are carried out in a dry glove box. The NaCl–2CsCl–UCl3 melts are prepared in two stages. A NaCl–2CsCl–UCl4 melt is prepared first by the chlorination of metallic uranium with gaseous chlorine, and then the prepared electrolyte is stored in contact with uranium to form a NaCl–2CsCl–UCl3 solution. Uranium alloys with low-melting metals are prepared prior to experiment by the electrolysis of the NaCl–2CsCl–UCl3 melt. The electrolysis time corresponds to conditions of one-phase or two-phase region formation. The high-temperature filtration of saturated alloys through a porous quartz filter is used to determine the uranium concentration in an alloy containing no intermetallic compounds. The dependences of the activity coefficients of γ-U in lead, tin, and Pb–Sn bimetallic alloy are detected. The temperature dependences of the emf of the galvanic cell are approximated by straight lines, and the values of emf depend on the nature of the alloy components and decrease in the order Sn > Pb–Sn > Pb. The solubility of uranium in the U–Pb, U–Pb–Sn, and U–Sn alloys is determined. The solubility of uranium is found to be low and almost independent of the alloy nature.
期刊介绍:
Russian Metallurgy (Metally) publishes results of original experimental and theoretical research in the form of reviews and regular articles devoted to topical problems of metallurgy, physical metallurgy, and treatment of ferrous, nonferrous, rare, and other metals and alloys, intermetallic compounds, and metallic composite materials. The journal focuses on physicochemical properties of metallurgical materials (ores, slags, matters, and melts of metals and alloys); physicochemical processes (thermodynamics and kinetics of pyrometallurgical, hydrometallurgical, electrochemical, and other processes); theoretical metallurgy; metal forming; thermoplastic and thermochemical treatment; computation and experimental determination of phase diagrams and thermokinetic diagrams; mechanisms and kinetics of phase transitions in metallic materials; relations between the chemical composition, phase and structural states of materials and their physicochemical and service properties; interaction between metallic materials and external media; and effects of radiation on these materials.