9918. Vanadium

Nomenclature

CAS number: 7440-62-2

Description and references

V; at. wt 50.9415; at. no. 23; valencies 2, 3, 4, 5. Group VB(5). Two naturally occurring isotopes: 51V (99.75%); 50V (0.25%); the latter is radioactive: T 6 × 1015 years. Artificial isotopes: 46-49; 52-54. Abundance in earth's crust: 0.01% by wt. Widespread in nature; over 65 minerals known including patronite (polysulfide), vanadinite (9PbO.3V2O5.PbCl2), roscoelite [2K2O.2Al2O3.(Mg,Fe)O.3V2O5.10SiO2.4H2O] and carnotite (K2O.2U2O3.V2O5.3H2O). [Carnotite is also an important source of uranium]. Discovered by Selstrm in 1830; prepd by Roscoe in 1869. Prepn: Prandtl, Manz, Z. Anorg. Allg. Chem. 79, 209 (1912); Marden, Rich, J. Ind. Eng. Chem. 19, 786 (1927); McKechnie, Seybolt, J. Electrochem. Soc. 97, 311 (1950); Gregory, Lilliendahl, ibid. 98, 395 (1951); Handbook of Preparative Inorganic Chemistry vol. 2, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1965) pp 1252-1255. Review: Clark, “Vanadium” in Comprehensive Inorganic Chemistry vol. 3, J. C. Bailar, Jr. et al., Eds. (Pergamon Press, Oxford, 1973) pp 491-551. Review of toxicology and human exposure: Toxicological Profile for Vanadium and Compounds (PB93-110880, 1992) 130 pp.

Properties

Light gray or white lustrous powder, fused hard lumps or body-centered cubic crystals; not tarnished in air and not appreciably affected by moisture at ordinary temp. mp 1917°. d18.7 6.11. Sp heat (20-100°) 0.12 cal/g/°C. Electrical resistivity 24.8 microhms/cm. Insol in water. Not attacked by hot or cold hydrochloric acid, by cold sulfuric acid. Reacts with hot sulfuric acid, hydrofluoric acid, nitric acid, aqua regia. Not attacked by bromine water, or by aq alkalies. The metal precipitates gold, silver and platinum from their salts; reduces mercuric salts to mercurous, ferric salts to ferrous.

Caution

Potential symptoms of overexposure to dust or fumes are irritation of eyes, skin, throat; green tongue, metallic taste, eczema; cough; fine rales, wheezing, bronchitis; dyspnea. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 328.

Use

Alloying agent in manuf of rust-resistant vanadium steel.