Chemically related to vanadium are the two elements tantalum and columbium or niobium.
The pure metal may be obtained by reducing vanadium dichloride in hydrogen, the operation being exceedingly difficult (for details, see Roscoe's original papers).
Gin, L'Electricien, 1903, 2 5, p. 5); and by the electrolysis of vanadium trioxide when heated in an evacuated glass tube (W.
The distillate is freed from vanadium by digestion with sodium amalgam.
The principal exports are gold, silver, copper (bars, regulus and ores), cobalt and its ores, lead and its ores, vanadium ores, manganese, coal, nitrate of soda, borate of lime, iodine, sulphur, wheat and guano.
For other methods of obtaining vanadium and its compounds, see Cowper Cowles, Engin.
Anodic polarization in potassium chloride solution renders molybdenum, niobium, ruthenium, tungsten, and vanadium passive (W.
Ammonium metavanadate is obtained when the hydrated vanadium pentoxide is dissolved in excess of ammonia and the solution concentrated.
Chem., 1905, 45, p. 35 2); by electrolysis in a bath of fused fluorspar containing a steel cathode and an anode composed of carbon and vanadium pentoxide (M.
Many salts of oxy-acids of vanadium are known, but of the more common oxy-acids, metavanadic acid, HV03, and pyrovanadic acid, H 4 V 2 0 7, alone appear to have been isolated.