Electrochemical and Thermodynamic Properties of Uranium on the Liquid Bismuth Electrode in LiCl-KCl Eutectic

Abstract

This work presents the electrochemical behaviors of U on a liquid Bi electrode and the formation of Bi-U intermetallic compounds in LiCl-KCl eutectic. It was found that the deposition of U on the liquid Bi electrode was a two-step process. The activity coefficient of U in the liquid Bi was determined by coulometric titration and in-situ open circuit chronpotentiometry versus two different reference electrodes at the temperature range of 723 to 813K. The solubility of U in liquid Bi was evaluated by pulse electrolysis. Furthermore, thermodynamic properties of Bi-U intermetallic compounds were measured by open circuit chronopotentiometry. The linear dependence of the Gibbs free energy of formation as a function of temperature was obtained, from which the enthalpy and entropy of formation were also determined. The activities and partial molar Gibbs free energies of U in two phase coexisting states were calculated through the measurement of electromotive force. Galvanostatic electrolysis was then conducted to prepare Bi-U intermetallic compound in the LiCl-KCl-UCl 3 melt on a liquid Bi electrode. The phase composition and microstructure of the alloy was characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) with Energy Dispersive Spectroscopy (EDS).

Electrochemical preparation and properties of a Mg–Li–Y alloyviaco-reduction of Mg(ii) and Y(iii) in chloride melts

“…At the beginning of the curve, the oxidation signal (B 0 ) is related to the formation of Cl 2 . 16,38,39 At the end of the curve, the reduction signal A is attributed to the formation of metal Li, and the other oxidation signal (A 0 ) is related to the dissolution of metal Li. In the electrochemical window, the black curve that corresponds to puried blank salt shows no additional reaction signal.…”

Electrode reaction of Pr on Sn electrode and its electrochemical recovery fromLiCl‐KClmolten salt

“…[8][9][10][11][12][13] Since molten salt has some excellent characteristics, 14,15 for instance, radiation resistance, short cooling time, and antiproliferative properties, pyrometallurgical technology, employing molten salt as medium, is considered as a promising method in the field of separation and extraction of actinides, 16,17 which mainly includes reduction extraction in molten saltliquid metal system, 18,19 electrorefining, 20,21 and electrochemical extraction using reactive cathodes. [22][23][24][25][26] Wherein, electrochemical extraction is the most extensive pyrochemical separation process. As the electroextraction of U and minor actinides proceeds, lanthanides will continue to accumulate in the solvent.…”

“…The recovery of actinide elements by partitioning and transmutation, considered as one of the promising options for spent fuel management, can make full use of nuclear fuel and minimize nuclear wastes, 7 which is conducive to increase the utilization rate of nuclear energy 8‐13 . Since molten salt has some excellent characteristics, 14,15 for instance, radiation resistance, short cooling time, and antiproliferative properties, pyrometallurgical technology, employing molten salt as medium, is considered as a promising method in the field of separation and extraction of actinides, 16,17 which mainly includes reduction extraction in molten salt‐liquid metal system, 18,19 electrorefining, 20,21 and electrochemical extraction using reactive cathodes 22‐26 . Wherein, electrochemical extraction is the most extensive pyrochemical separation process.…”

Electroreduction of Dy(III) assisted by Zn and its co‐deposition with Zn(II) in LiCl–KCl molten salt

“…Therein, noble metals with low fusing point and boiling point are often used as liquid electrodes for two reasons: (i) a high diffusion rate of Lns in liquid electrodes benefiting the recovery of Lns and (ii) the easy separation of electrode materials and Lns using vacuum distillation. In the past few decades, the recovery of Lns from molten salts on liquid electrodes, for example, Zn, [ 7,9,10,12–17 ] Bi, [ 5,18–21 ] Ga, [ 22–24 ] Cd, [ 25–29 ] and Sn, [ 11,30 ] has been studied, which demonstrates the feasibility of recovering Lns from molten salts on liquid electrodes. Metallic Zn has a lower toxicity compared with Cd metal, and the recovery on liquid Zn electrode is safe and environmentally friendly.…”