The Preparation of Vanadium Tetrachloride from Vanadium Dichloride Oxide and Vanadium Trichloride and the Hydrogen Reduction Process of Vanadium Tetrachloride

Article abstract of DOI:10.1246/bcsj.53.2843

The reactions of VCl2O and VCl3 with chlorine, and the reaction of VCl3O, formed by the chlorination of VCL2O, with chlorine in the presence of carbon were examined.The products formed by the reaction between gaseous VCl4 and hydrogen at various temperatures, and the behavior of VCl3 and VCl2 on heating in a hydrogen stream were examined.The reaction between VCl2O and chlorine occurs above ca. 120 deg C and proceeds markedly above ca. 170 deg C to form VCl3O.VCl4 can be obtained by passing the gaseous VCl3O together with chlorine through a carbon bed held at ca. 700 deg C.The reaction between VCl3 and chlorine occurs above ca. 80 deg C and proceeds markedly above ca. 170 deg C to form VCl4.The hydrogen reduction process of VCl4 in the vapor phase may be represented as follows: The reaction between VCl4 and hydrogen, 2VCl4(g) + H2(g) -> 2VCl3(s) + 2HCl(g), proceeds above ca. 500 deg C to form VCl3.Subsequently, the hydrogen reduction of the VCl3, 2VCl3(s) + H2(g) -> 2VCl2(s) + 2HCl(g), and the disproportionation of the VCl3, 2VCl3(s) -> VCl4(g), proceed to form VCl2.Above ca. 620 deg C, the reaction between the VCl2 and hydrogen, VCl2(s) + H2(g) -> V(s) + 2HCl(g), proceeds to form vanadium.