Alumina Solubility in Na3AlF6-K3AlF6-AlF3 Molten Salt System Prospective for Aluminum Electrolysis at Lower Temperature

Chemical Research in Chinese Universities ›› 2012, Vol. 28 ›› Issue (1): 142-146.

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Alumina Solubility in Na₃AlF₆-K₃AlF₆-AlF₃ Molten Salt System Prospective for Aluminum Electrolysis at Lower Temperature

LI Jie, YUAN Chang-fu, TIAN Zhong-liang*, WANG Jia-wei, LAI Yan-qing, LIU Ye-xiang

School of Metallurgical Science and Engineering, Central South University, Changsha 410083, P. R. China

Received:2011-02-23 Revised:2011-04-01 Online:2012-01-25 Published:2011-12-27
Contact: Zhong-Liang TIAN E-mail:tianzhongliang@126.com
Supported by:
Supported by the National Basic Research Program of China(No.2005CB623703) and the National High-Tech Research and Development Program of China(No.2008AA030503).

Abstract

Abstract: The alumina solubility in the title system within the composition range of KR{m(K₃AlF₆)/[m(K₃AlF₆)+ m(Na₃AlF₆)]} 10%―50%, a ternary Na₃AlF₆-K₃AlF₆-AlF₃ molten system with 23%―29%(mass fraction) AlF₃ was investigated by measuring the mass loss of a rotating sintered corundum disc. And the following empirical equation was derived when superheat degree was no more than 60 ℃: w(Al₂O₃)_sat=A×(T/1000)^B, where A= –1.85774+ 26.754234w(AlF₃)^–0.3683–0.00783KR^2.363+0.010266KR^2.3048+0.7902w(AlF₃)^0.00652, B=112.4625–53.2567w(AlF₃)^0.4236+ 5.1079w(AlF₃)^0.9241+0.01542w(AlF₃)^1.3540. Considering both higher alumina solubility and not too high superheat degree are required, alumina solubility of different compositions at not the same temperature but the same superheat degree was studied, which will be more industrial helpful for selecting prospective compositions. The results show that the composition deserved to be further tested in lower temperature cells is 10%―30% KR and 23%―26%(mass fraction) AlF₃.

Key words: Alumina solubility, Lower temperature electrolyte, Na₃AlF₆-K₃AlF₆-AlF₃ molten salt system, Aluminum electrolysis

LI Jie, YUAN Chang-fu, TIAN Zhong-liang, WANG Jia-wei, LAI Yan-qing, LIU Ye-xiang. Alumina Solubility in Na₃AlF₆-K₃AlF₆-AlF₃ Molten Salt System Prospective for Aluminum Electrolysis at Lower Temperature[J]. Chemical Research in Chinese Universities, 2012, 28(1): 142-146.

References

[1] Thonstad J., Rolseth S., Trans. Inst. Min. Metall., Sect. C, 2005, 114,188 [2] Wang J. W., Lai Y. Q, Tian Z. L., Li J., Liu Y. X., Proc. TMS-AIME,Light Met., 2007, 525 [3] Solheim A., Rolseth S., Skybakmoen E., St?en L., Sterten ?., St?reT., Proc. TMS-AIME, Light Met., 1995, 452 [4] Grjotheim K., Welch B. J., Aluminum Smelter Technology―APure and Applied Approach, 2nd Ed., Aluminum-Verlag, Düsseldorf,1988, 52 [5] Danielik V., Gabèová J., J. Therm. Anal. Calorim., 2004, 76, 763 [6] Barton C. J., Bratcher L. M., Grimes W. R.; Ed.: Thoma R. E.,Phase Diagrams of Nuclear Reactor Materials., US AT. EnergyComm., Oak Ridge, 1959, 32 [7] Wang J. W., Lai Y. Q., Tian Z. L., Li J., Liu Y. X., Proc.TMS-AIME, Light Met., 2008, 513 [8] Huang Y. G., Lai Y. Q., Tian Z. L., Li J., Liu Y. X., Li Q., Proc.TMS-AIME, Light Met., 2008, 519 [9] Meng Q., Kan S., Lu S., Ding H., Zhang X., Chinese Journal ofRare Metals, 2010, 34, 905 [10] Zhou C., Ma S., Li G., Sheng J., Non Ferrous Metals, 1998, 50, 81 [11] Fenerty A., Hollingshead E. A., J. Electrochem. Soc., 1960, 107, 993 [12] Xiao L., George L., Wills S. F., Valerie A., Proc. TMS-AIME, LightMet., 1994, 359 [13] Foster P. A. Jr., J. Am. Ceram. Soc., 1975, 58, 288 [14] Skybakmoen E., Solheim A., Sterten ?., Metall. Mater. Trans. B,1997, 28B, 82 [15] Skybakmoen E., Solheim A., Sterten ?., Proc. TMS-AIME, LightMet., 1990, 317 [16] Yang J., Graczyk D. G., Wunsch C., Hryn J. N., Proc. TMS-AIME,Light Met., 2007, 537 [17] Levich V. G., Physicochemical Hydrodynamics, Prentice-Hall, Inc.,Englewood Cliffs, New Jersey, 1962, 172 [18] Kryukovsky V. A., Frolov A. V., Tkatcheva O. Y., Redkin A. A.,Zaikov Y. P., Khokhlov V. A., Apisarov A. P., Proc. TMS-AIME,Light Met., 2006, 411 [19] Robert E., Oslen J. E., Danek V., Tixon E., Ostvold T., Gilbert B., J.Phys. Chem. B, 1997, 101, 9447 [20] Grjotheim K., Kvande H., Introduction to Aluminum Electrolysis―Understanding the Hall-Héroult Process, 2nd Ed., Aluminum-Verlag, Düsseldorf, 1993, 48

Alumina Solubility in Na₃AlF₆-K₃AlF₆-AlF₃ Molten Salt System Prospective for Aluminum Electrolysis at Lower Temperature

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