Vanadium is a monocrystal metal. It is grey and is a transition element. Vanadium has very high melting point 1890℃，boiling point 3380℃. The density of vanadium is 6.110 g/cm³ at room temperature. It is a refractory metal including niobium, tantalum, tungsten and molybdenum. Vanadium possesses quality of ductility, hard grain, nonmagnetic. It is not easy to oxidize in the air and it can dissolve in hydrofluoric acid, nitric acid and aqua regia. Furthermore, vanadium is resistant to corrosion and rather stable in alkali, sulfuric acid, hydrochloric acid. Vanadium is widely used in metallurgy, space navigation, chemical engineering and battery industries in the form of ferro-vanadium, vanadium compounds.
Our country extracts vanadium mostly from vanadium ore and stone coal, adopting technical process of sodium salt roasting--water immersion--acid deposition--alkaline bath--ammonium salt deposition--metavanadic acid ammonium pyrolysis. This technique exposes the main shortcoming is that during the process of roasting it generates great amount of hydrogen chloride, chlorine poisonous gas. In addition, the sewage water contains lots of salts that contaminate environment severely and vanadium conversion rare is low. To solve these issues, many experts did a large deal of research work. They also found out raw ore oxidation roasting--alkaline leaching, calcium salt roasting--ammonium carbonate leaching, raw ore acid leaching or boiling out-furnace carbonic acid leaching, bacterial leaching--sodium salt roasting--water leaching residues and etc. This new method obtains better results.
Vanadium is an important alloyed element mainly used in steel industry. The steel containing vanadium has great intensity, big tenacity, good abrasive resistance and other excellent performances. It can broadly supply in machineries, automobiles, shipbuilding, railways, aviation, bridges, electronic techniques, national defense and etc. These fields occupy 85% of vanadium consumption. Steel industry take the biggest percent of vanadium. Vanadium requests in steel field directly affects vanadium market. Approximately 10% of vanadium is used for producing titanium alloys in aerospace. Vanadium is a stabilizer and reinforcer in titanium alloys, which can titanium alloys have a good ductility and plasticity. In addition, Primarily vanadium can be used as catalyst and enhancer in chemical industry. Vanadium is also can used for producing rechargeable hydrogen or vanadium redox storage battery.