Vanadium Disilicide, VSi₂

Vanadium Disilicide, VSi₂, is prepared by reducing a mixture of vanadium trioxide and silicon with magnesium; vanadium pentoxide can also be employed with the addition of fluorspar to the mixture. Gin used a mixture of the pentoxide, silica, and coke. Vanadium disilicide is a very stable compound; it forms metallic prisms which melt at 1655° C., have a specific gravity of 4.42, and are hard enough to scratch glass. It is attacked by hydrofluoric acid, hydrogen chloride gas, and fused alkalis.

Hypovanadic oxide, VO₂, and vanadium pentoxide, V₂O₅, both dissolve in hydrofluosilicic acid to yield a vanadyl fluosilicate and a vanadium fluosilicate, both of doubtful composition.