Electrical conductivity optimization of the Na3AlF6-Al2O3-Sm2O3 molten salts system for Al-Sm intermediate binary alloy production

Chun-fa Liao; Yun-fen Jiao; Xu Wang; Bo-qing Cai; Qiang-chao Sun; Hao Tang

doi:10.1007/s12613-017-1493-3

Volume 24 Issue 9

Sep. 2017

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Article Navigation > International Journal of Minerals, Metallurgy and Materials > 2017 > 24(9): 1034-1042

Chun-fa Liao, Yun-fen Jiao, Xu Wang, Bo-qing Cai, Qiang-chao Sun, and Hao Tang, Electrical conductivity optimization of the Na₃AlF₆-Al₂O₃-Sm₂O₃ molten salts system for Al-Sm intermediate binary alloy production, Int. J. Miner. Metall. Mater., 24(2017), No. 9, pp. 1034-1042. https://doi.org/10.1007/s12613-017-1493-3

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Chun-fa Liao, Yun-fen Jiao, Xu Wang, Bo-qing Cai, Qiang-chao Sun, and Hao Tang, Electrical conductivity optimization of the Na3AlF6-Al2O3-Sm2O3 molten salts system for Al-Sm intermediate binary alloy production, Int. J. Miner. Metall. Mater., 24(2017), No. 9, pp. 1034-1042. https://doi.org/10.1007/s12613-017-1493-3

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Research Article

Electrical conductivity optimization of the Na₃AlF₆-Al₂O₃-Sm₂O₃ molten salts system for Al-Sm intermediate binary alloy production

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Corresponding author:
Yun-fen Jiao E-mail: yyjyf@163.com
Received: 30 December 2016; Revised: 22 March 2017; Accepted: 23 March 2017

Abstract

Abstract

Metal Sm has been widely used in making Al-Sm magnet alloy materials. Conventional distillation technology to produce Sm has the disadvantages of low productivity, high costs, and pollution generation. The objective of this study was to develop a molten salt electrolyte system to produce Al-Sm alloy directly, with focus on the electrical conductivity and optimal operating conditions to minimize the energy consumption. The continuously varying cell constant (CVCC) technique was used to measure the conductivity for the Na₃AlF₆-AlF₃-LiF-MgF₂-Al₂O₃-Sm₂O₃ electrolysis medium in the temperature range from 905 to 1055℃. The temperature (t) and the addition of Al₂O₃ (W(Al₂O₃)), Sm₂O₃ (W(Sm₂O₃)), and a combination of Al₂O₃ and Sm₂O₃ into the basic fluoride system were examined with respect to their effects on the conductivity (κ) and activation energy. The experimental results showed that the molten electrolyte conductivity increases with increasing temperature (t) and decreases with the addition of Al₂O₃ or Sm₂O₃ or both. We concluded that the optimal operation conditions for Al-Sm intermediate alloy production in the Na₃AlF₆-AlF₃-LiF-MgF₂-Al₂O₃-Sm₂O₃ system are W(Al₂O₃) + W(Sm₂O₃)=3wt%, W(Al₂O₃):W(Sm₂O₃)=7:3, and a temperature of 965 to 995℃, which results in satisfactory conductivity, low fluoride evaporation losses, and low energy consumption.
- aluminium oxide;
- samarium oxide;
- molten salt;
- electrical conductivity;
- regression analysis;
- Al-Sm intermediate alloy

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