AskDefine | Define vanadium

Dictionary Definition

vanadium n : a soft silvery white toxic metallic element used in steel alloys; it occurs in several complex minerals including carnotite and vanadinite [syn: V, atomic number 23]

User Contributed Dictionary

see Vanadium

English

Noun

  1. A chemical element, (symbol V) with an atomic number of 23; it is a transition metal, used in the production of specialist steels.

Synonyms

Translations

External links

For etymology and more information refer to: http://elements.vanderkrogt.net/elem/v.html (A lot of the translations were taken from that site with permission from the author)

Extensive Definition

Vanadium () is a chemical element that has the symbol V and atomic number 23. A soft and ductile element, vanadium naturally occurs in about 65 different minerals and is used mainly to produce certain alloys. It is one of the 26 elements found in most living organisms.

Notable characteristics

Vanadium is a soft and ductile, silver-grey metal. It has good resistance to corrosion by alkalis, sulfuric and hydrochloric acid. It oxidizes readily at about 933 K (660 C). Vanadium has good structural strength and a low fission neutron cross section, making it useful in nuclear applications. Although a metal, it shares with chromium and manganese the property of having valency oxides with acid properties.
Common oxidation states of vanadium include +2, +3, +4 and +5. A popular experiment with ammonium vanadate NH4VO3, reducing the compound with zinc metal, can demonstrate colorimetrically all four of these vanadium oxidation states. An oxidation state of +1 is rarely seen.

Applications

Approximately 80% of vanadium produced is used as ferrovanadium or as a steel additive. Other uses:

History

Vanadium (named after Vanadis, the Scandinavian goddess of beauty) was originally discovered by Andrés Manuel del Río (a Spanish-born Mexican mineralogist) in Mexico City, in 1801. He discovered the element after being sent a sample of "brown lead" ore (now named vanadinite). Through experimentation, he found it to form salts with a wide variety of colors, so he named the element panchromium (Greek: all colors). He later renamed this compound erythronium, since most of the salts turned red when heated. The French chemist Hippolyte Victor Collet-Descotils incorrectly declared that del Río's new element was only impure chromium. Del Río thought himself to be mistaken and accepted the statement of the French chemist that was also backed by del Río's friend Baron Alexander von Humboldt.
In 1831, Sefström of Sweden rediscovered vanadium in a new oxide he found while working with some iron ores and later that same year Friedrich Wöhler confirmed del Río's earlier work. Later, George William Featherstonhaugh, one of the first US geologists, suggested that the element should be named "rionium" after del Río, but this never happened.
Metallic vanadium was isolated by Henry Enfield Roscoe in 1867, who reduced vanadium(III) chloride VCl3 with hydrogen. The name vanadium comes from Vanadis, a goddess in Scandinavian mythology, because the element has beautiful multicolored chemical compounds.. Nonetheless, there is no evidence that vanabins carry oxygen, in contrast to hemoglobin and hemocyanin. A form of vanadium, vanadyl sulfate, seems to improve glucose control in people with type 2 diabetes.
Several species of macrofungi, namely Amanita muscaria and related species, are known as effective accumulators of vanadium (up to 500 mg/kg in dry weight). Vanadium is present as an organometallic compound (called amavadine) in fungal fruit-bodies. However, the biological importance of the accumulation process is unknown.

Mineral supplement in drinking water

Most continental waters show a vanadium concentration of less than 3 ppb. However, the groundwater of Mt. Fuji contains a very high concentration of vanadium—up to 150 ppb. This vanadium is solubilized from the basalt by the groundwater. The vanadium content in Mt. Fuji becomes higher at places nearer the summit and deeper in the ground. Recently this high-vanadium water of Mt. Fuji has been sold by many companies as an agent to cope with diabetes. However, there is no concrete evidence for its efficacy. The rainbow trout living in the Mt. Fuji water showed much higher accumulation of vanadium in kidneys and bone.

Occurrence

Vanadium is never found unbound in nature but it does occur in about 65 different minerals among which are patronite VS4, vanadinite Pb5(VO4)3Cl, and carnotite K2(UO2)2(VO4)2.3H2O.
By far the greatest proportion of the world's vanadium production is sourced from vanadium-bearing magnetite found in ultramafic gabbro bodies. From these ores vanadium can be calcined to form ferrovanadium, or can be recovered from the vanadium steel smelting process which is widely used in Russia and China.
Vanadium is also present in bauxite, and in carbon containing deposits such as crude oil, coal, oil shale and tar sands. Vanadium has also been detected spectroscopically in light from the Sun and some other stars.
Much of the vanadium metal being produced is now made by calcium reduction of V2O5 in a pressure vessel. Vanadium is usually recovered as a by-product or co-product, and so world resources of the element are not really indicative of available supply.

Isolation

Vanadium is available commercially and production of a sample in the laboratory is not normally required. Commercially, routes leading to metallic vanadium as main product are not usually required as enough is produced as byproduct in other processes.
In industry, heating of vanadium ore or residues from other processes with salt NaCl or sodium carbonate Na2CO3 at about 850°C gives sodium vanadate NaVO3. This is dissolved in water and acidified to give a red solid which in turn is melted to form a crude form of vanadium pentoxide V2O5. Reduction of vanadium pentoxide with calcium gives pure vanadium. An alternative suitable for small scales is the reduction of vanadium pentachloride VCl5 with hydrogen or magnesium. Many other methods are also in use.
Industrially, most vanadium is used as an additive to improve steels. Rather than proceed via pure vanadium metal it is often sufficient to react the crude of vanadium pentoxide V2O5 with crude iron. This produces ferrovanadium suitable for further work.

Compounds

Vanadium pentoxide V2O5 is used as a catalyst principally in the production of sulfuric acid. It is the source of vanadium used in the manufacture of ferrovanadium. It can be used as a dye and color-fixer.
Vanadyl sulfate VOSO4, also called vanadium(IV) sulfate oxide hydrate, is used as a relatively controversial dietary supplement, primarily for increasing insulin sensitivity and body-building. Whether it works for the latter purpose has not been proven, and there is some evidence that athletes who take it are merely experiencing a placebo effect.
Anhydrous VCl4 is a liquid at room temperature and reacts violently with water; it can be used, in conjunction with an appropriate nitrogen compound, for vapour deposition of hard VN layers http://www3.interscience.wiley.com/cgi-bin/abstract/109609704/ABSTRACT. Vanadium pentafluoride is an extremely powerful fluorinating agent, capable of perfluorinating chloroalkanes http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TGD-4D5KSCG-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0e95853a43997369cb00b05980e7f894, and has been proposed (eg http://www.isrd.tpu.ru/english/orion/html/11-2.htm) as a safe and economical substitute for XeF2; it is also liquid at room temperature.
Orthovanadate VO43- is used in biochemistry as a phosphate analogue; in protein crystallography it can be used to make phosphate binding sites very visible in electron density.
Vanadium forms polyoxometalate cluster compounds, including V10 O24.

Toxicity of vanadium compounds

The toxicity of vanadium depends on its physico-chemical state; particularly on its valence state and solubility. Tetravalent VOSO4 has been reported to be more than 5 times as toxic as trivalent V2O3 (Roschin, 1967). Vanadium compounds are poorly absorbed through the gastrointestinal system. Inhalation exposures to vanadium and vanadium compounds result primarily in adverse effects to the respiratory system (Sax, 1984; ATSDR, 1990; Ress et al., 2003; Worle-Knirsch et al., 2007). Quantitative data are, however, insufficient to derive a subchronic or chronic inhalation reference dose. Other effects have been reported on blood parameters after oral or inhalation exposures (Scibior et al., 2006; Gonzalez-Villalva et al., 2006), on liver (Kobayashi et al., 2006), neurological development in rats (Soaso and Garcia, 2007), and other organs.
There is little evidence that vanadium or vanadium compounds are reproductive toxins or teratogens. Vanadium pentoxide was reported to be carcinogenic in male rats and male and female mice by inhalation in an NTP study (Ress et al., 2003), although the interpretation of the results has recently been disputed (Duffus, 2007). Vanadium has not been classified as to carcinogenicity by the U.S. EPA (1991a).

Various oxidation states of vanadium ions

It is known that vanadium gets the oxidation states +2, +3, +4, +5. To observe the colours of these states, ammonium metavanadate (NH4VO3) can be used as a starting agent. It must be acidified beforehand so dioxovanadium(V) ion, VO2+ (yellow +5 oxidation number) is produced. In alkaline medium, the stable form of vanadium(V) state is VO3-.
Adding zinc powder and concentrated hydrochloric acid continuously, VO2+ is reduced into blue VO2+.
It can be seen that during the reaction, the mixture is green in colour as the original yellow of the +5 state and the blue of the +4 are present.
Continuously adding Zn powder and concentrated HCl, blue VO2+ is reduced to green V3+. V3+ is then reduced to violet V2+ by Zn powder and concentrated HCl again.

Isotopes

Naturally occurring vanadium is composed of one stable isotope 51V and one radioactive isotope 50V with a half-life of 1.5×1017 years. 24 artificial radioisotopes have been characterized (in the range of mass number between 40 and 65) with the most stable being 49V with a half-life of 330 days, and 48V with a half-life of 15.9735 days. All of the remaining radioactive isotopes have half-lives shorter than an hour, the majority of them below 10 seconds. In 4 isotopes, metastable excited states were found (including 2 metastable states for 60V).
The primary decay mode before the most abundant stable isotope 51V is electron capture. The next most common mode is beta decay. The primary decay products before 51V are element 22 (titanium) isotopes and the primary products after are element 24 (chromium) isotopes.

Precautions

Powdered metallic vanadium is a fire hazard, and unless known otherwise, all vanadium compounds should be considered highly toxic. Generally, the higher the oxidation state of vanadium, the more toxic the compound is. The most dangerous compound is vanadium pentoxide.
The Occupational Safety and Health Administration (OSHA) has set an exposure limit of 0.05 mg/m3 for vanadium pentoxide dust and 0.1 mg/m3 for vanadium pentoxide fumes in workplace air for an 8-hour workday, 40-hour work week.
The National Institute for Occupational Safety and Health (NIOSH) has recommended that 35 mg/m3 of vanadium be considered immediately dangerous to life and health. This is the exposure level of a chemical that is likely to cause permanent health problems or death.

Footnotes

References

  • Los Alamos National Laboratory – Vanadium
  • High vanadium content in Mt.Fuji groundwater and its relevance to the ancient biosphere by Tatsuo Hamada in Vanadium in Environment. Part 1: Chemistry and Biochemistry. Edited by Jerome O. Nriagu. Page 97-123. 1998. John Wilen & Sons, Inc.
  • Duffus JH. Carcinogenicity classification of vanadium pentoxide and inorganic vanadium compounds, the NTP study of carcinogenicity of inhaled vanadium pentoxide, and vanadium chemistry. Regul Toxicol Pharmacol 2007 Feb;47(1):110-4.
  • Gonzalez-Villalva A, Fortoul TI, Avila-Costa MR, et al. Thrombocytosis induced in mice after subacute and subchronic V2O5 inhalation. Toxicol Ind Health 2006 Apr;22(3):113-6.
  • Kobayashi K, Himeno S, Satoh M, et al. Pentavalent vanadium induces hepatic metallothionein through interleukin-6-dependent and -independent mechanisms. Toxicology 2006 Dec 7;228(2-3:162-170.
  • Ress NB, Chou BJ, Renne RA, et al. Carcinogenicity of inhaled vanadium pentoxide in F344/N rats and B6C3F1 mice. Toxicol Sci 2003 Aug;74(2):287-96.
  • Scibior A, Zaporowska H, Ostrowski J. Selected haematological and biochemical parameters of blood in rats after subchronic administration of vanadium and/or magnesium in drinking water. Arch Environ Contam Toxicol 2006 Aug;51(2):287-95.
  • Soazo M, Garcia GB. Vanadium exposure through lactation produces behavioral alterations and CNS myelin deficit in neonatal rats. Neurotoxicol Teratol 2007 Jul-Aug;29(4):503-10.
  • Worle-Knirsch JM, Kern K, Schleh C, et al. Nanoparticulate vanadium oxide potentiated vanadium toxicity in human lung cells. Environ Sci Technol 2007 Jan 1;41(1):331-6.
vanadium in Afrikaans: Vanadium
vanadium in Arabic: فاناديوم
vanadium in Asturian: Vanadiu
vanadium in Bengali: ভ্যানাডিয়াম
vanadium in Belarusian: Ванадый
vanadium in Bosnian: Vanadijum
vanadium in Bulgarian: Ванадий
vanadium in Catalan: Vanadi
vanadium in Czech: Vanad
vanadium in Corsican: Vanadiu
vanadium in Danish: Vanadium
vanadium in German: Vanadium
vanadium in Estonian: Vanaadium
vanadium in Modern Greek (1453-): Βανάδιο
vanadium in Spanish: Vanadio
vanadium in Esperanto: Vanado
vanadium in Basque: Banadio
vanadium in Persian: وانادیوم
vanadium in French: Vanadium
vanadium in Friulian: Vanadi
vanadium in Manx: Vanaadjum
vanadium in Galician: Vanadio
vanadium in Korean: 바나듐
vanadium in Armenian: Վանադիում
vanadium in Hindi: वनडियम
vanadium in Croatian: Vanadij
vanadium in Ido: Vanadio
vanadium in Indonesian: Vanadium
vanadium in Icelandic: Vanadín
vanadium in Italian: Vanadio
vanadium in Hebrew: ונדיום
vanadium in Javanese: Vanadium
vanadium in Kannada: ವನಾಡಿಯಮ್
vanadium in Swahili (macrolanguage): Vanadi
vanadium in Haitian: Vanadyòm
vanadium in Kurdish: Vanadyûm
vanadium in Latin: Vanadium
vanadium in Latvian: Vanādijs
vanadium in Luxembourgish: Vanadium
vanadium in Lithuanian: Vanadis
vanadium in Lojban: jinmrvanadi
vanadium in Hungarian: Vanádium
vanadium in Malayalam: വനേഡിയം
vanadium in Marathi: व्हेनेडियम
vanadium in Dutch: Vanadium
vanadium in Japanese: バナジウム
vanadium in Norwegian: Vanadium
vanadium in Norwegian Nynorsk: Vanadium
vanadium in Occitan (post 1500): Vanadi
vanadium in Uzbek: Vanadiy
vanadium in Polish: Wanad
vanadium in Portuguese: Vanádio
vanadium in Romanian: Vanadiu
vanadium in Quechua: Wanadyu
vanadium in Russian: Ванадий
vanadium in Sicilian: Vanadiu
vanadium in Simple English: Vanadium
vanadium in Slovak: Vanád
vanadium in Slovenian: Vanadij
vanadium in Serbian: Ванадијум
vanadium in Serbo-Croatian: Vanadijum
vanadium in Finnish: Vanadiini
vanadium in Swedish: Vanadin
vanadium in Tamil: வனேடியம்
vanadium in Thai: วาเนเดียม
vanadium in Vietnamese: Vanađi
vanadium in Turkish: Vanadyum
vanadium in Ukrainian: Ванадій
vanadium in Chinese: 钒
Privacy Policy, About Us, Terms and Conditions, Contact Us
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2
Material from Wikipedia, Wiktionary, Dict
Valid HTML 4.01 Strict, Valid CSS Level 2.1