2023-Sustainable Industrial Processing Summit
Intl. Symp on Electrochemistry, Molten Salts, Corrosion and Recycling
| Editors: | F. Kongoli, R. Fehrmann, V. Papangelakis, I. Paspaliaris, G. Saevarsdottir, G. Kipouros, R. Singh, F. Wang, D. Macdonald, R. Gupta, M. Barinova, F. Ahmed, H. Ozgunay, K. Tang, N.N. Thanh, C. Gaidau, K. Kolomaznik |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2023 |
| Pages: | 114 pages |
| ISBN: | 978-1-989820-98-8 (CD) |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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ELECTRICAL CONDUCTIVITY of MOLTEN (LiCl-KCl)eut. - PbCl2 MIXTURES
Alexei Potapov1; Alexander Salyulev1;1INSTITUTE OF HIGH TEMPERATURE ELECTROCHEMISTRY, Ekaterinburg, Russian Federation;
Type of Paper: Regular
Id Paper: 102
Topic: 13
Abstract:
For the first time the electrical conductivity of 13 compositions of (3LiCl-2KCl) - PbCl2 molten mixtures has been measured. The measurements were carried out at the temperatures of 631-994 K in the concentration range of 0-100 mol. % with the increment of ~ 10 mol. % PbCl2 using capillary quartz cells with platinum electrodes [1] and the AC-bridge method at the input frequency of 75 kHz.
The electrical conductivity of all melts increased smoothly with temperature and decreased as the concentration of PbCl2 increased. Its deviations from the additive course did not exceed 3.5% at 750 K and 8% at 950 K. The maximum deviations are located near the PbCl2 concentrations of 30–40 mol. %. The specific electrical conductivity (κ, S/cm) of several molten mixtures is exemplified below:
κ = -5.1439 + 1.2565*10-2T - 4.5503*10-6T2 , (632-988 K) 4 mol.% PbCl2;
κ = -4.3114 + 1.0750*10-2T - 3.8926*10-6T2 , (662-976 K) 30 mol.% PbCl2;
κ = -4.9041 + 1.1759*10-2T - 4.4114*10-6T2 , (684-920 K) 70 mol.% PbCl2.
The density, molar volumes and molar conductivity of all studied molten mixtures were calculated. Relative deviations of molar volumes from additive values decreased with increasing temperature. The maximum deviations were observed at the PbCl2 concentration of about 20 mol. % (3.8% at 773 K and 2.9% at 923 K).
When PbCl2 is added to the LiCl-KCl melt, the divalent lead cation forms complex groups with chlorine anions that are somewhat stronger than the lithium cation. However, the difference between the ionic moments of Li+ and Pb2+ is small. Relatively free and mobile K+ ions are located in the second coordination sphere. The molar electrical conductivity polytherms of molten mixtures (3LiCl-2KCl) - PbCl2 are almost rectilinear over the entire concentration range, which also indicates a rather weak interaction in the system.
The data on electrical conductivity and molar volumes of the (3LiCl-2KCl) - PbCl2 melts are compared with those earlier obtained in our studies on the (3LiCl-2KCl) - CdCl2 [2] and (3LiCl-2KCl) - SrCl2 molten mixtures [3]. The results are discussed in terms of the structure of these melts.
Keywords:
Chloride; Conductivity; Density; Lithium; Mixtures; Moltensalt; Potassium;References:
[1] A.M. Potapov, L. Rycerz, M. Gaune-Escard, Z. Naturforsch. 62a (2007) 431-440.[2] A. Salyulev, A. Potapov, V. Shishkin, V. Khokhlov, Electrochim. Acta 182 (2015) 821-826.
[3] A. Salyulev, A. Potapov, J. Chem. Eng. Data 66 (2021) 4563-4571.