Abstract
The reaction between MgO and graphite powders under flowing argon atmosphere was studied using a dynamic thermogravimetric method. In the temperature range 293 to 1973 K, the effects of compacting pressure, magnesia/carbon ratio, heating rate, Ar carrier-gas flow rate, and CO-partial pressure were investigated. An experimentally determined reaction mechanism was proposed and discussed. The reduction process could be divided into two stages. The first stage includes the direct reaction between MgO and graphite particles and partial gas-solid reaction at relatively low temperature (below 1750 K). The overall reaction rate depends on the solid phase-boundary reaction between magnesia and carbon particles. The second stage is the gas-solid reaction between CO and MgO, which determines the overall reaction rate. The apparent activation energies of the two stages were estimated to be 208.29 and 374.13 kJ/mol, respectively.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
B.L. Mordike and T. Ebert: Mater. Sci. Eng. A, 2001, vol. 302, pp. 37–45.
A. Froats: Light Metal, Metallurgical Society of AIME, New York, NY, 1980, pp. 969–79.
H. Baudson, F. Debucquoy, M. Huger, C. Gault, and M. Rigaud: J. Eur. Ceram. Soc., 1999, vol. 19, pp. 1895–1901.
G.D. Pickering and J.D. Batchelor: Am. Ceram. Soc. Bull., 1971, vol. 50, pp. 611–14.
J.Y. Shan, K. Okumura, M. Kuwabara, and M. Sano: Tetsu-to-Hagane-J. Iron Steel Inst. Jpn., 2001, vol. 87, pp. 635–42.
J. Yang, S. Ozaki, R. Kakimoto, K. Okumura, M. Kuwabara, and M. Sano: Iron Steel Inst. Jpn. Int., 2001, vol. 41, pp. 945–54.
D.J. Min, J.W. Han, and W.S. Chung: Metall. Mater. Trans. B, 1999, vol. 30B, pp. 215–21.
Naiyang Ma and N.A. Warner: Can. Metall. Q., 1999, vol. 38, pp. 165–73.
N.S. Sundar Murti and V. Seshadri: Trans. Iron Steel Inst. Jpn., 1982, vol. 22, pp. 925–33.
Y.K. Rao: Chem. Eng. Sci., 1974, vol. 29, pp. 1435–45.
Y.K. Rao: Metall. Trans, 1971, vol. 2, pp. 1439–47.
L. Hong, K. Okumura, and M. Sano: Metall. Mater. Trans. B, 1999, vol. 30B, pp. 1003–08.
D.R. Poirier and G.H. Geiger: Transport Phenomena in Materials Processing, 1st ed., TMS, Warrendale, PA, 1994, pp. 419–61.
W.J. Moore: Physical Chemistry, 3rd ed., Maruzen Co. Ltd., Tokyo, Japan, 1962, pp. 273–76.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Rongti, L., Wei, P. & Sano, M. Kinetics and mechanism of carbothermic reduction of magnesia. Metall Mater Trans B 34, 433–437 (2003). https://doi.org/10.1007/s11663-003-0069-y
Received:
Issue Date:
DOI: https://doi.org/10.1007/s11663-003-0069-y