2024 - Sustainable Industrial Processing Summit
SIPS 2024 Volume 16. Intl. Symp on Electrochemistry, Molten Salts, Corrosion, Recycling and Battery
| Editors: | F. Kongoli, C.A. Amatore, R. Fehrmann, G. Kipouros, I. Paspaliaris, G. Saevarsdottir, R. Singh, R. Gupta, M. Halama, D. Macdonald, F. Wang, M. Barinova, F. Ahmed, C. Gaidau, X. Guo, K. Kolomaznik, H. Ozgunay, K. Tang, N.N. Thanh, S. Yefremova, K. Aifantis, Z. Bakenov, C. Capiglia, V. Kumar, A. U. H. Qurashi, A. Tressaud, R. Yazami |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2024 |
| Pages: | 243 pages |
| ISBN: | 978-1-998384-34-1 (CD) |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
CD shopping page
ELECTRICAL CONDUCTIVITY OF MULTICOMPONENT MOLTEN MIXTURES BASED ON LiCl-KCl EUTECTIC
Alexander Salyulev1; Alexei Potapov1;1INSTITUTE OF HIGH TEMPERATURE ELECTROCHEMISTRY, Ekaterinburg, Russian Federation;
Type of Paper: Regular
Id Paper: 170
Topic: 13
Abstract:
During the pyrochemical processing of spent nuclear fuel, multicomponent molten mixtures are formed based on the LiCl-KCl eutectic, containing UCl3, PuCl3 and a large number of chlorides of elements - fission fragments (CeCl3, NdCl3, SrCl2, BaCl2, CdCl2, CsCl, RbCl, etc.). Electrochemical methods are supposed to be used to separate fission products. Therefore, it is important to know the electrical conductivity of such melts. However, obtaining experimental data for many various multicomponent mixtures is practically insurmountable challenge. Therefore, it is necessary to find a way to reliably estimate their electrical conductivity.
To develop a model and semi-empirical method for assessing the electrical conductivity of multicomponent melts of arbitrary composition with good accuracy, a fairly wide base of experimental data is required. To expand this base, we measured the electrical conductivity of a large number of binary, ternary and various multicomponent, including uranium-containing molten mixtures in wide ranges of temperatures and concentrations, using capillary quartz cells with platinum electrodes and the AC-bridge method. The density of such mixtures was estimated and the molar electrical conductivity was calculated. The results are systematized, and some of the results are published in [1–4].
In all cases, the electrical conductivity of molten mixtures increases with increasing temperature. When heavy cations are added to the molten LiCl-KCl eutectic, the formation of complex chloride anions, which are less mobile than individual ions, occurs. This leads to a decrease in the concentration of current carriers Li+, K+ and, especially, Cl–, and as a result, a decrease in the electrical conductivity of the melt.
The electrical conductivity of molten mixtures is a highly non-additive property. Its deviations from the additive sum of electrical conductivities of individual components can reach tens of percent. The stronger the interaction in the system, the greater the deviation of the molar electrical conductivity from additivity.
We propose to evaluate the electrical conductivity of multicomponent mixtures as an additive sum of the electrical conductivities of binary mixtures. We have shown that in this case, the electrical conductivities of molten ternary and quaternary mixtures differ from the experimentally found values by no more than 2%, that is, within the experimental error, since deviations from additivity have been already taken into account in binary mixtures analysis. In other words, we bring the multicomponent molten mixture closer to the ideal one by variation of the subsystems (components of the mixture).