The effect of calcium fluoride on extracting magnesium from magnesite and calcium carbonate by silicothermal reduction in flowing argon

  • Junhua Guo Northeastern University
  • Daxue Fu Northeastern University
  • Jibiao Han Northeastern University
  • Zonghui Ji Northeastern University
  • Yaosong Wang Northeastern University
  • Tingan Zhang Northeastern University
Keywords: Magnesium; Calcium fluoride; Magnesite; Dicalcium silicate; Silicothermal process

Abstract


At present, the production of magnesium is mainly carried out semi-continuously with ferrosilicon as reducing agent under high temperature and high vacuum. In order to continuously produce magnesium, a new method of extracting magnesium from low-grade magnesite and calcium carbonate by silicothermal method in flowing inert gas was proposed. The effects of calcium fluoride (CaF2) on decomposition rate, decomposition kinetics, reduction rate of magnesia, and crystal type of dicalcium silicate in reduction slag were investigated in the paper. The experimental results showed that calcium fluoride could accelerate the decomposition of carbonate, and had no side effect on the calcined products. In addition, the analysis results of DTA curves showed that calcium fluoride could reduce the decomposition reaction activation energy and the reaction temperature of carbonate in the prefabricated pellets. The results of reduction experiments showed that proper calcium fluoride could promote the reduction rate of magnesia, and in the temperature range of 1250℃ ~ 1350℃, with the same timeframe, the corresponding calcium fluoride contents were 5%, 3%, and 1% respectively when the reduction rate reached the maximum. Excessive calcium fluoride reduced the reduction rate of magnesia, but it promoted the transformation of dicalcium silicate to γ phase in the reduction slag.

References

[1] Y. He, M. Jiang, Present situation of mining and utilization andexisting problems of magnesite resource of our country, Refractories &Lime, 37 (3) (2012) 25-28. https://doi.org/10.16425/j.cnki.1673-7792.2012.03.007
[2] L. Tian, A. Tahmasebi, J. L. Y, An experimental study on thermal decomposition behaviorof magnesite, Journal of Thermal Analysis and Calorimetry, 118 (2014) 1577-1584. https://doi.org/10.1007/s10973-014-4068-9
[3] Y. N. Zhao, G. C. Zhu, A technology of preparing honeycomb-like structure MgO from low grade magnesite, International Journal of Mineral Processing, 126 (10) (2014) 35-40. https://doi.org/10.1016/j.minpro.2013.11.006
[4] Q. J. Gao, G. Wei, X. Jiang, H. Y. Zheng, F. M. Shen, Characteristics of calcined magnesite and it’s application in oxidized pellet production, Journal of Iron and Steel Research International, 21 (4) (2014) 408-412. https://doi.org/10.13228/j.boyuan.issn1006-706x.2014.04.009
[5] Q. D. Hou, X. D. Luo, M. T. Li, D. An, Z. P. Xie, Non-isothermal kinetic study of high-grade magnesite thermal decomposition and morphological evolution of MgO, International Journal of Applied Ceramic Technology, 00 (2021) 1-8. https://doi.org/10.1111/ijac.13708
[6] C. Ghosh, A. Ghosh, H. S. Tripathi, J. Ghosh, M. K. Haldar, Studies on densification, mechanical, microstructural andstructure–properties relationship of refractory aggregates prepared from Indian magnesite by changing lime-silica ratio, Ceramics International, 40 (10B) (2014) 16791–16798. https://doi.org/10.1016/j.ceramint.2014.08.018
[7] A. Kumar, S. Kumar, N. K. Mukhopadhyay, Introduction to magnesium alloy processing technology and development of low-cost stir casting process for magnesium alloy and its composites, Journal of Magnesium and Alloys, 6 (3) (2018) 245-254. https://doi.org/10.1016/j.jma.2018.05.006
[8] R. E. Brown, Magnesium in the 21st century, Advanced Materials & Processes, 167 (1) (2009) 31-33.
[9] B. L. Mordike, T. Ebert. Properties-applications-potential, Materials Science and Engineering: A, 302 (1) (2001) 37-45. https://doi.org/10.1016/s0921-5093(00)0135 1-4
[10] J. D. Du, W. J. Han, Y. H. Peng, Life cycle greenhouse gases, energy and cost assessment of automobiles using magnesium from Chinese Pidgeon process, Journal of Cleaner Production, 18 (2) (2010) 112-119. https://doi.org/10.1016/j.jclepro.2009.08.013
[11] F. Cherubini, M. Raugei, and S. Ulgiati, LCA of magnesium production: Technological overview and worldwide estimation of environmental burdens, Resources, Conservation and Recycling, 52 (8-9) (2008) 1093-1100. https://doi.org/10.1016/j.resconrec.2008.05.001
[12] D. X. Fu, N. X. Feng, Y. W. Wang, J. P. Peng, Y. Z. Di, Kinetics of extracting magnesium from mixture of calcined magnesite and calcined dolomite by vacuum aluminothermic reduction, Transactions of Nonferrous Metals Society of China, 24 (3) (2014) 839–847. https://doi.org/10.1016/S1003-6326(14)63133-2
[13] Y. Tian, B. Q. Xu, B. Yang, C. B. Yang, T. Qu, D. C. Liu, Y. N. Dai, Magnesium production by carbothermic reduction in vacuum, Journal of Magnesium and Alloys, 3 (2015) 149-154. https://doi.org/10.1016/j.jma.2015.04.001
[14] C. B. Yang, Y. Tian, T. Qu, B. Yang, B. Q. Xu, Y. N. Dai, Magnesium vapor nucleation in phase transitions and condensation under vacuum conditions, Transactions of Nonferrous Metals Society of China, 24 (2) (2014) 561-569. https://doi.org/10.1016/S1003-6326(14)63096-X
[15] M. Abdellatif. Review of the development work on the Mintek thermal magnesium process (MTMP), Journal South African Institute Mining Metallurgy, 111 (2011) 393-399.
[16] T. A. Zhang, Z. H. Dou, Z. M. Zhang, Y. Liu, G. Z. Lv, J. C. He, A rapid and continuous process for magnesium production. CN104120282-B, 2015. [Patent].
[17] Y. W. Wang, J. You, N. X. Feng, W. X. Hu, Influence of CaF2 addition on vacuum aluminothermic reduction, Chinese Journal of Vacuum Science and Technology, 32 (10) (2012) 889-895. https://doi.org/10.3969/j.issn.1672-7126.2012.10.07
[18] C. Wang, C. Zhang, S. J. Zhang, L. J. Guo, The effect of CaF2 on the magnesium production with silicothermal process, International Journal of Mineral Processing, 142 (2015) 147-153. https://doi.org/10.1016/j.minpro.2015.04.017
[19] T Zhang. Investigation on the reaction between MgO-CaO-CaF2 and Al-C powders to extract magnesium under atmospheric pressure, Journal of Magnesium and Alloys, 7 (2) (2019) 328-334. https://doi.org/10.1016/j.jma.2019.03.001
[20] J. H. Guo, T. A. Zhang, D. X. Fu, J. B. Han, Z. H. Ji, Z. H. Dou, Research on properties of prefabricated pellets of silicothermic process after calcination in flowing argon atmosphere, Magnesium Technology, (2020) 303-307. https://doi.org/10.1007/978-3-030-36647-6_45
[21] M Wen, T. A. Zhang , Z. H. Dou, Y. Guan, R. Zhang, Two-stage calcination of dolomite pellets for mg-extraction by silicothermic reduction in vacuum, Chinese Journal of Vacuum Science and Technology, 34 (11) (2014) 1242-1245. https://doi.org/10.13922/j.cnki.cjovst.2014.11.19
[22] D. X. Fu, T. A. Zhang, L. K. Guan, Z. H. Dou, M. Wen,., Magnesium production by silicothermic reduction of dolime in pre-prepared dolomite pellets, JOM, 68 (12) (2016) 3208-3213. https://doi.org/10.1007/s11837-016-2034-7
[23] J. H. Guo, D. X. Fu, J. B. Han, Z. H. Ji, Z. H. Dou, T. A. Zhang, Kinetics of extracting magnesium from prefabricated pellets by silicothermic process under flowing argon atmosphere, Journal of Mining and Metallurgy Section B-Metallurgy, 56 (3) (2020) 379-386. https://doi.org/10.2298/JMMB200712031G
[24] Y. S. Che, Z. H. Hao, J. P. Zhu, Z. H. Fu, J. He, J. X. Song, Kinetic mechanism of magnesium production by silicothermy in Argon Flowing, Thermochimica Acta, 681 (2019) 178397. https://doi.org/10.1016/j.tca.2019.178397
[25] S. Vyazovkin, Computational aspects of kinetic analysis. Part C. The ICTAC Kinetics Project - The light at the end of the tunnel?, Thermochimica Acta, 355 (2000) 155-163. https://doi.org/10.1016/S0040-6031(00)00445-7
[26] A. K. Burnham, Computational aspects of kinetic analysis. Part D: The ICTAC Kinetics Project-Multi-thermal-history model-fitting methods and their relation to isoconversional methods, Thermochimica Acta, 355 (2000) 165-170. https://doi.org/10.1016/S0040-6031(00)00446-9
[27] Y. Tian, H. X. Liu, B. Yang, T. Qu, Y. N. Dai, P. Peng, Magnesium extraction from magnesia by carbothermic reduction in vacuum, Chinese Journal of Vacuum Science and Technology, 32 (9) (2012) 814-819. https://doi.org/10.3969/j.issn.1672-7126.2012.04.08
[28] I. M. Morsi, K. A. E. Barawy, M. B. Morsi, S. R. Adbel-Gawad, Silicothermic reduction of dolomite Ore under inert atmosphere, Canadian Metallurgical Quarterly, 41 (1) (2002) 15-28. https://doi.org/10.1179/cmq.2002.41.1.15
[29] I. M. Pritts, K. E. Daugherty, The effect of stabilizing agents on the hydration rate of β-C2S, Cement and Concrete Research, 6 (6) (1976) 783-795. https://doi.org/10.1016/0008-8846(76)90008-9
[30] M. Regourd, Crystal chemistry of Portland cement phases, Applied Science Publishers, New York, 1983.
[31] X. J. Feng, S. Z. Long, Effect of minor ions on the stability of β-C2S and its mechanism, Journal of the Chinese Ceramic Society, 13 (4) (1985) 424-431.
[32] Z. Y. Wang, M. Wang, Z. J. Wen, W. Zhang, Progress on study of dicalcium silicate and low calcium cement with dicalcium silicate as a main mineral composition, Materials Review, 30 (1) (2016) 73-78. https://doi.org/10.11896/j.issn.1005-023X.2016.01.012
[33] K. Fukuda, I. Maki, S. Ito, T. Miyake, Structural change in phosphorus-bearing dicalcium silicate, Journal of the Ceramic Society of Japan, 105 (2) (1997) 117-121. https://doi.org/10.2109/jcersj.105.117

Published
2022/01/19
How to Cite
Guo, J., Fu, D., Han, J., Ji, Z., Wang, Y., & Zhang, T. (2022). The effect of calcium fluoride on extracting magnesium from magnesite and calcium carbonate by silicothermal reduction in flowing argon. Journal of Mining and Metallurgy, Section B: Metallurgy, 58(1), 19-28. Retrieved from https://aseestant.ceon.rs/index.php/jmm/article/view/31384
Issue
Vol. 58 No. 1 (2022)
Section
Original Scientific Paper

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