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. - ZrCl4 MIXTURES
Alexei Potapov1; Alexander Salyulev1;1INSTITUTE OF HIGH TEMPERATURE ELECTROCHEMISTRY, Ekaterinburg, Russian Federation;
Type of Paper: Regular
Id Paper: 110
Topic: 13
Abstract:
To perfect the technological processes of electrodeposition and electrorefining of zirconium, information on the electrical conductivity of ZrCl4 solutions in molten alkali metal chlorides is needed. Most of ZrCl4-containing melts have a high vapor pressure and, hence, are not suitable for industrial applications. Only two concentration windows in each MCl-ZrCl4 system (M is an alkali metal) are suitable. These are the high and low temperature ranges with 0-30 or 55-70 mol. %; ZrCl4, respectively, where the vapor pressure above the melt is less than 1 atm. Previously, we carried out a series of experiments on the study of the electrical conductivity of such melts [1–4].
In this work, for the first time the electrical conductivity of molten mixtures (LiCl-KCl)eut.-ZrCl4 have been measured in the ZrCl4 concentration range of 0-30 mol. %; and in a wide temperature range (652–1075 K). The measurements were carried out in a capillary-type quartz cell of a special design [5]. The use of a low-melting solvent (LiCl-KCl eutectic) made it possible to significantly (by hundreds of degrees) lower the melting temperature and, accordingly, the saturation vapor pressure of molten mixtures.
It was found that the electrical conductivity of molten mixtures (LiCl-KCl)eut.-ZrCl4 (0.9-2.8 S/cm) is close to the electrical conductivity of high-temperature ZrCl4 melts with the same concentration of chlorides of various alkali metals (0.6-3.5 S/cm). We studied these melts earlier [3, 4]. The obtained values of electrical conductivity are much higher than the electrical conductivity of low-melting, more concentrated (55–75 mol.%; ZrCl4) molten mixtures (0.1–0.5 S/cm) [1, 2].
The experimental results are discussed taking into account the available spectroscopic data on the structure of ZrCl4-containing molten mixtures. In particular, it was noted that with an increase in the concentration of ZrCl4, the concentration of its relatively low-mobile complex groups ZrCl62- increases proportionally. In this complex, all 6 chloride ions are strongly bound to the tetravalent zirconium cation. This leads to a decrease in the concentration of the main current carriers: K+, Li+, Cl– and to a decrease in the electrical conductivity of the melts.
The liquidus line in the (LiCl-KCl)eut.-ZrCl4 quasi-binary system has been constructed for the first time.
Keywords:
Chloride; Conductivity; Ion; Lithium; Mixtures; Moltensalt; Potassium; LiCl-KCl; ZrCl4References:
[1] A.B. Salyulev, V.A. Khokhlov, A.A. Redkin, Russ. Metallurgy (Metally) 2014 (2014) 659-663.[2] A.B. Salyulev, A.M. Potapov, Z. Naturforsch. 73a (2018) 259-263.
[3] A.B. Salyulev, A.M. Potapov, Z. Naturforsch. 74a (2019) 925-930.
[4] A.B. Salyulev, A.M. Potapov, Z. Naturforsch. 77a (2022) 941-948.
[5] A.B. Salyulev, V.A. Khokhlov, N.I. Moskalenko, Russ. Metallurgy (Metally) 2017 (2017) 95-99.