Vanadium - Properties and Applications of Vanadium

In 1801, del Rio discovered Vanadium (V), although a French chemist dismissed his discovery claiming he had merely found impure chromium. Believing the French chemist, del Rio accepted his finding. It was not until 1830, that Sefstrom rediscovered the element and named it after the Scandinavian goddess Vanadis, due to its attractive multicoloured compounds.

However it was not until 1867, that Roscoe reduced the chloride with hydrogen to isolate the first sample of vanadium. It took another 60 years before vanadium was produced with purities as high as 99.3 to 99.8%.

Occurrence

Vanadium is found in approximately 54 different minerals as well as phosphate rock, certain iron ores, some crude oils (in the form of complexes) and meteorites. Some of the more important minerals in which vanadium is found include carnotite, roscoelite, vanadinite and patronite.

Isotopes

Natural vanadium is comprised of two isotopes. V⁵¹ makes up 99.74% of vanadium, while V⁵⁰ makes up the balance, although seven other isotopes are recognised. V⁵⁰ is slightly radioactive possessing a half life of 6 x 10¹⁵ years.

Production of Vanadium

Commercially, vanadium is produced by reducing vanadium trichloride with magnesium metal or a mixture of magnesium and sodium or via the calcium reduction of V₂O₅ in a pressure vessel.

Health Aspects

Vanadium is toxic and care is required when handling vanadium and its compounds

Key Properties

Pure vanadium is:

•          Bright white in appearance
•          Soft
•          Ductile
•          Has good structural strength
•          Possesses good corrosion resistance to alkalis, sulphuric acid, hydrochloric acid and salt water
•          It oxidises readily at temperatures greater then 660°C
•          Has a low fission neutron cross section

Applications

The most important use of vanadium is as an additive for steel, with approximately 80% of vanadium going into ferrovanadium, a steel additive. It is used for the production of rust resistant, spring and high speed tool steels. It is also added to steels to stabilise carbides.

Vanadium foil is also used to bond titanium to steel.

Due to its low fission neutron cross section vanadium is also used in nuclear applications.

Vanadium compounds are also used in a number of applications such as:

•          Vanadium pentoxide as a catalyst in the ceramics industry
•          As a mordent in the printing and dyeing of fabrics
•          In the manufacture of aniline black

Source: AZoM.com