Publication Date:
2017-06-06
Description:
Based on the phase equilibria of the CaO-SiO 2 -VO x system determined experimentally at 1873K and the oxygen partial pressure of 6.9×10 -11 atm, the isothermal section diagram of the system was constructed. Apart from the simple oxides SiO 2 and V 2 O 3 , three complex crystal phases CaV 2 O 4 , Ca 2 SiO 4 dissolving V 2 O 3 and CaVO 3 dissolving SiO 2 were found in the present investigated composition range. The solubility of V 2 O 3 in Ca 2 SiO 4 phase can reach 5 mass %, and the CaVO 3 phase dissolves about 5% mass SiO 2 . Furthermore, the thermodynamic activities of VO x and SiO 2 in the determined single liquid region were measured by equilibrating the melts with liquid copper. The activity coefficient of SiO 2 decreases linearly with the increase of the basicity of the melts and is almost irrelevant to the total content of vanadium oxides. The activities of vanadium oxides increase slightly with the increase of the basicity but are mainly determined by the total content of vanadium oxides in the melts. With the increase of the basicity, the activity coefficient of VO 1.5 increases almost linearly, whereas those of VO 2 and VO 2.5 decrease gradually. This article is protected by copyright. All rights reserved.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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