2016-Sustainable Industrial Processing Summit
SIPS 2016 Volume 9: Molten Salts and Ionic Liquids, Energy Production
| Editors: | Kongoli F, Gaune-Escard M, Turna T, Mauntz M, Dodds H.L. |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2016 |
| Pages: | 390 pages |
| ISBN: | 978-1-987820-24-9 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Electrochemistry and Separation of UF4 in LiCl-KCl Eutectic
Tiejian Zhu1;1SHANGHAI INSTITUTE OF APPLIED PHYSICS, CHINESE ACADEMY AND SCIENCES, Shanghai, China;
Type of Paper: Regular
Id Paper: 156
Topic: 13
Abstract:
The electrochemistry of UF4 in LiCl-KCl eutectic on tungsten electrode was studied at 723K. Both cyclic and square wave voltammetry showed that U4+ was reduced to U0 via two steps. Firstly, U4+ underwent a reversible and diffusion controlled reduction to form U3+ followed by a subsequent three-electron reduction to metallic uranium on tungsten electrode around -1.6V(vs Ag/AgCl, 5mol%), the latter of which is quasi reversible due to the negative shift of the reduction potential as the sweep rate increases. Cyclic voltammetry and chronopotentiometry were employed to determine the diffusion coefficients both U3+ and U4+ in the presence of F- ions in LiCl-KCl eutectic, which indicates the influence of F- on the diffusion process of uranium cations in comparison to the previously published data obtained in chloride molten salts. Based on the above experimental results, separation of uranium fluoride from LiCl-KCl molten salt was carried out using pulse current electrolysis, which revealed that up to 98% uranium could be removed from molten salt. Our experimental investigation demonstrates the possibility of direct separation of UF4 from LiCl-KCl molten salt by using electrochemical methods.