Electrochemical reduction of zirconium dioxide in chloride-oxide melts

Omel’chuk, АО
Gritsai, LV
Dopov. Nac. akad. nauk Ukr. 2019, 1:63-71
https://doi.org/10.15407/dopovidi2019.01.063
Section: Chemistry
Language: Ukrainian
Abstract: 

It is shown that the electrochemical reduction of zirconium dioxide in molten electrolyte mixtures that are based on calcium and magnesium compounds on a liquid gallium cathode can be used to obtain a finely divided zirconium powder of high purity. The recovery degree depends on the cation composition of the electrolyte mixture. The best performance is provided by a melt based on compounds of calcium and sodium chloride.

Keywords: electrochemical reduction, finely divided zirconium powder, molten electrolytes, zirconium dioxide
References: 

1. Elinson, C. V. & Petrov, K. I. (1960). Zirconium. Physical and chemical methods of analysis. Moscow: Atomizdat (in Russian).
2. Adamson, R. B. (Ed.) (2010). Zirconium production and technology: the Kroll Medal papers 1975—2010. Michigan: ASTM International. doi: https://doi.org/10.1520/RPS2-EB
3. Xu, L., Xiao, Y., van Sandwijk, A., Xu, Q. & Yang, Y. (2015). Production of nuclear grade zirconium: A review. J. Nucl. Mater., 466, pp. 21-28. doi: https://doi.org/10.1016/j.jnucmat.2015.07.010
4. Mohandas, K. S. (2011, November). Direct electrochemical conversion of metal oxides to metal by molten salt electrolysis: An overview. Proceedings of the Fray International Symposium Metals and Materials Processing in a Clean Environment. Vol. 3: Molten Salts & Ionic Liquids (pp. 195-217). Cancun: QC FLOGEN. doi: https://doi.org/10.13140/2.1.2610.4969
5. Mohandas, K. S. & Fray, D. J. (2009). Electrochemical deoxidation of solid zirconium dioxide in molten calcium chloride. Metall. Mater. Trans. B, 40, Iss. 5, pp. 685-699. doi: https://doi.org/10.1007/s11663-009-9263-x
6. Abdelkader, A. M., Daher, A., Abdelkareem, R. A. & El-Kashif, E. (2007). Preparation of zirconium metal by the electrochemical reduction of zirconium oxide. Metall. Mater. Trans. B, 38, Iss. 1, pp. 35-44. doi: https://doi.org/10.1007/s11663-006-9016-z
7. Pat. 111779 UA. IPC С25С 3/26, С22В 34/14, Method for the zirconium obtaining by electrolysis of melts, Оmel’chuk, А.А., Gritsai, L.V., Savchuk, R.N., Publ. 10.06.2016 (in Ukrainian).
8. Savchuk, R. N., Gritsai, L. V. & Omel’chuk, A. A. (2016). Solubility of calcium and zirconium oxides in melts CaO—(CaCl2—MCl)eut and CaO—CaCl2—MCl (M—Li, Na, K). ECS Transactions, 75, Iss. 15, pp. 373-377.
doi: https://doi.org/10.1149/07515.0373ecst
9. Freidina, E. B. & Fray, D. J. (2000). Study of the ternary system CaCl2—NaCl—CaO by DSC. Thermochim. Acta, 354, pp. 59-62. doi: https://doi.org/10.1016/S0040-6031(00)00454-8
10. Data from All Phase Diagrams. Retrieved from http://www.crct.polymtl.ca/fact/documentation/FS_All_PDs.htm
11. Barin, I. (1995). Thermochemical data of pure substances. 3rd ed. Weinheim; New York; Basel; Cambridge; Tokyo: VCH. doi: https://doi.org/10.1002/9783527619825
12. Delimarsky, Yu. K. (1986). Theoretical bases of ionic melts electrolysis. Moscow: Metallurgiya (in Russian).
13. Zhang, Y. (1982). Electronegativities of elements in valence states and their applications. 2. A scale for strengths of Lewis acids. Inorg. Chem., 21, pp. 3889-3893. doi: https://doi.org/10.1021/ic00141a006