The pathways of the carbothermic reduction of V2O3 were investigated in the temperature range from 1373 to 1873 K by chemical and X-ray diffraction analyses.
In the case of a mixture of V2O3 and C in a molar ratio of 1/3 under pressures between 0.67 and 20 Pa, the VC-VO phase with low oxygen-concentrations is formed below 1373 K, and the VC-VO phase with medium oxygen-concentrations is formed above 1373 K. The former changes to the latter with increasing temperature. From the latter, the V2C phase and the VC-VO phase with high oxygen-concentrations are formed, and then the V4O phase is formed by the reaction of these two phases. Finally the vanadium phase is formed by the reaction between the V4O phase and the V2C phase.
In the case of a mixture of V2O3 and C in a molar ratio of 1/4 under pressures between 0.67 and 20 Pa, the final product is the V2C phase which is formed from the VC-VO phase with medium oxygen-concentrations.
In the case of a molar ratio of 1/5, the final product, the VC phase, is formed by two different paths under pressures between 0.67 and 20 Pa, while it is formed by a single path under a pressure of 1330 Pa.
(Received April 19, 1982)
* This paper was originally published in Japanese in J. Japan Inst. Metals, 46 (1982), 258.
** Department of Materials Science and Engineering, Himeji Institute of Technology, Shosya, Himeji 671-22, Japan.
*** Toyo High School affiliated to Toyo University, Himeji 671-22, Japan.
© 2002 The Japan Institute of Metals
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