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Electrical conductivity of systems based on Na3AlF6-SiO2 melt

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Abstract

The electrical conductivity of molten binary and ternary mixtures based on the NaF-AlF3-SiO2 system was investigated by means of a tube-cell (composed of pyrolytic boron nitride) with stationary electrodes. An impedance/gain-phase analyser (National Instruments; a high-performance modular chassis controlled by Labview™ software) was used for the cell impedance measurement. The conductivity was found to vary linearly with temperature in all the mixtures investigated. The concentration dependence of electrical conductivity (isotherms) thus obtained was divided into two parts. The first represents the concentration region of up to 10 mole % of SiO2, the second the region with a higher concentration of SiO2 (from 10 mole % to 40 mole %). While the conductivity decreased considerably with the concentration of SiO2 in the second part, it increased surprisingly in the low concentration range. From these results, the influence of electrolyte composition and temperature on the electrical conductivity was examined.

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References

  • Abramov, G. A., Vetyukov, M. M., Gupalo, I. P., Kostyukov, A. A., & Lozhkin, L. N. (1953). Teoreticheskie osnovy elektrometallurgii alyuminia (pp. 502–503). Moscow, USSR: Metallurgizdat. (in Russian)

    Google Scholar 

  • Apisarov, A. P., Redkin, A. A., Zaikov, Y. P., Chemezov, O. V., & Isakov, A. V. (2011). Electrical conductivity of molten fluoride-chloride electrolytes containing K2SiF6 and SiO2. Journal of Chemical & Engineering Data, 56, 4733–4735. DOI: 10.1021/je200717n.

    Article  CAS  Google Scholar 

  • Belyaev, A. I. (1947). Fiziko-khimicheskie protsessy pri elektrolize alyuminia. Moscow, USSR: Metallurgizdat. (in Russian)

    Google Scholar 

  • Belyaev, A. I., Zhemchuzhina, Ye. A., & Firsanova, L. A. (1957). Fyzicheskaya khimia rasplavlennykh solei. Moscow, USSR: Metallurgizdat. (in Russian)

    Google Scholar 

  • Elwell, D., & Feigelson, R. S. (1982). Electrodeposition of solar silicon. Solar Energy Materials, 6, 123–145. DOI: 10.1016/0165-1633(82)90014-4.

    Article  CAS  Google Scholar 

  • Elwell, D., & Rao, G. M. (1988). Electrolytic production of silicon. Journal of Applied Electrochemistry, 18, 15–22. DOI: 10.1007/bf01016199.

    Article  CAS  Google Scholar 

  • Fellner, P., & Matiašovský, K. (1973). Chemical reactions in molten Na3AlF6-SiO2-Al2O3-AlF3. Chemické Zvesti, 27, 737–741.

    CAS  Google Scholar 

  • Fellner, P., Kobbeltvedt, O., Sterten, Å., & Thonstad, J. (1993). Electrical conductivity of molten cryolite-based binary mixtures obtained with a tube-type cell made of pyrolytic boron nitride. Electrochimica Acta, 38, 589–592. DOI: 10.1016/j.bbr.2011.03.031.

    Article  CAS  Google Scholar 

  • Grjotheim, K., Matiašovský, K., Fellner, P., & Silný, A. (1971). Electrolytic deposition of silicon and of silicon alloys Part I: Physicochemical properties of the Na3AlF6-Al2O3-SiO2 mixtures. Canadian Metallurgical Quarterly, 10, 79–82. DOI: 10.1179/000844371795103224.

    Article  CAS  Google Scholar 

  • Grjotheim, K., Krohn, C., Malinovský, M., Matiašovský, K., & Thonstad, J. (1982). Aluminium electrolysis: Fundamentals of the Hall-Héroult process (2nd ed., chapter 5.3). Düsseldorf, Germany: Aluminium-Verlag.

    Google Scholar 

  • Hashishin, T., Kaneko, Y., Iwanaga, H., & Yamamoto, Y. (1999a). The synthesis of silicon nitride whiskers from SiO2-N2-Na3AlF6 system. Journal of Materials Science, 34, 2193–2197. DOI: 10.1023/a:1004596717922.

    Article  CAS  Google Scholar 

  • Hashishin, T., Kaneko, Y., Iwanaga, H., & Yamamoto, Y. (1999b). Silicon carbide whiskers synthesized from SiO2-CH4-Na3AlF6 system. Journal of Materials Science, 34, 2189–2192. DOI: 10.1023/a:1004544701084.

    Article  CAS  Google Scholar 

  • Hills, G. J., & Djordjević, S. (1968). Electrode polarization in conductance measurements, with special reference to molten salt systems. Electrochimica Acta, 13, 1721–1726. DOI: 10.1016/0013-4686(68)80156-2.

    Article  CAS  Google Scholar 

  • Híveš, J., Thonstad, J., Sterten, A., & Fellner, P. (1996). Electrical conductivity of molten cryolite-based mixtures obtained with a tube-type cell made of pyrolytic boron nitride. Metallurgical and Materials Transaction B, 27, 255–261. DOI: 10.1007/bf02915051.

    Google Scholar 

  • Janz, J. G., Allen, B. C., Bansal, N. P., Murphy, R. M., & Tomkins, R. P. T. (1979). Physical properties data compilations relevant to energy storage. II. Molten salts: Data on single and multi-component salt systems. Washington, DC, USA: U.S. Government Printing Office. (NSRDS-NBS 61, Part II)

    Google Scholar 

  • Kim, K. B., & Sadoway, D. R. (1992). Electrical conductivity measurements of molten alkaline-earth fluorides. Journal of The Electrochemical Society, 139, 1027–1033. DOI: 10.1149/1.2069335.

    Article  CAS  Google Scholar 

  • Monnier, R., & Barakat, D. (1957). Contribution à l’étude du comportement de la silice dans les bains de cryolithe fondue. Helvetica Chimica Acta, 40, 2041–2045. DOI: 10.1002/hlca.19570400706.

    Article  CAS  Google Scholar 

  • Oishi, T., Watanabe, M., Koyama, K., Tanaka, M., & Saegusa, K. (2011). Process for solar grade silicon production by molten salt electrolysis using aluminum-silicon liquid alloy. Journal of The Electrochemical Society, 158, E93–E99. DOI: 10.1149/1.3605720.

    Article  CAS  Google Scholar 

  • Robbins, G. D. (1969). Measurement of electrical conductivity in molten fluorides. A survey. Journal of The Electrochemical Society, 116, 813–818. DOI: 10.1149/1.2412059.

    Article  CAS  Google Scholar 

  • Sokhanvaran, S., Thomas, S., & Barati, M. (2012). Charge transport properties of cryolite-silica melts. Electrochimica Acta, 66, 239–244. DOI:10.1016/j.electacta.2012.01.077.

    Article  CAS  Google Scholar 

  • Solheim, A., & Sterten, Å. (1997). Activity data for the system NaF-AlF3. In J. Thonstad (Ed.), Proceedings of the Ninth International Symposium on Light Metals Production, August 18–21, 1997 (pp. 225). Trondheim, Norway: NTNU.

    Google Scholar 

  • Šimko, F. (2012). Thermal analysis of (NaF/AlF3)-FeF3 and (NaF/AlF3)-FeO systems. Chemical Papers, 66, 235–238. DOI: 10.2478/s11696-011-0114-2.

    Article  Google Scholar 

  • Šimko, F., Macková, I., & Netriová, Z. (2011). Density of the systems (NaF/AlF3)-AlPO4 and (NaF/AlF3)-NaVO3. Chemical Papers, 65, 85–89. DOI: 10.2487/s11696-010-0074-y.

    Article  Google Scholar 

  • Thonstad, J., Fellner, P., Haarberg, G. M., Híveš, J., Kvande, H., & Sterten, Å. (2001). Aluminium electrolysis (3rd edition, chapters 1, 9, and 10.). Düsseldorf, Germany: Aluminium-Verlag.

    Google Scholar 

  • Tomkins, R. P. T., Janz, G. J., & Andalaft, E. (1970). The polarization correction in conductance measurements. Journal of The Electrochemical Society, 117, 906–907. DOI: 10.1149/1.2407670.

    Article  CAS  Google Scholar 

  • Wang, X., Peterson, R. D., & Tabereaux, A. T. (1992). Electrical conductivity of cryolitic melts. In Proceedings of the 121st TMS Annual Meeting, March 1–5, 1992 (pp. 481–488). San Diego, CA, USA: The Minerals, Metals & Materials Society.

    Google Scholar 

  • Weill, D. F., & Fyfe, W. S. (1964). The 1010° and 800°C isothermal sections in the system Na3AIF6-AI2O3-SiO2. Journal of The Electrochemical Society, 111, 582–585. DOI: 10.1149/1.2426187.

    Article  CAS  Google Scholar 

  • Yasuda, K., Nohira, T., Hagiwara, R., & Ogata, Y. H. (2007). Direct electrolytic reduction of solid SiO2 in molten CaCl2 for the production of solar grade silicon. Electrochimca Acta, 53, 106–110. DOI: 10.1016/j.electacta.2007.01.024.

    Article  CAS  Google Scholar 

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Correspondence to Michal Korenko.

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Korenko, M., Priščák, J. & Šimko, F. Electrical conductivity of systems based on Na3AlF6-SiO2 melt. Chem. Pap. 67, 1350–1354 (2013). https://doi.org/10.2478/s11696-013-0393-x

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