Vanadium

Symbol: V Density: 6 g/cm^3 Atomic Number: 23 Melting point: 3470 °F

Vanadium is a solid, ductile transition metal with a silvery gray appearance. It has good corrosion resistance to alkalis, sulfuric acid, hydrochloric acid, and salt waters. The metal oxidizes readily above 660°C to form V 2 O 5. Industrially, most vanadium produced is used as an additive to improve steels.
 * Brief description:**

Vanadium is a steel-grey, corrosion-resistant metal, which exists in oxidation states ranging from -1 to +5. Metallic vanadium does not occur in nature, and the most common valence states are +3, +4, and +5. The pentavalent form (VO3-) predominates in extracellular body fluids whereas the quadrivalent form (VO +2 ) is the most common intracellular form. Because of its hardness and its ability to form alloys, vanadium (i.e., ferrovanadium) is a common component of hard steel alloys used in machines and tools. Although most foods contain low concentrations of vanadium (< 1 ng/g), food is the major source of exposure to vanadium for the general population. High air concentrations of vanadium occur in the occupation setting during boiler-cleaning operations as a result of the presence of vanadium oxides in the dust. The lungs absorb soluble vanadium compounds (V 2 O 5 ) well, but the absorption of vanadium salts from the gastrointestinal tract is poor. The excretion of vanadium by the kidneys is rapid with a biological half-life of 20-40 hours in the urine. Vanadium is probably an essential trace element, but a vanadium-deficiency disease has not been identified in humans. The estimated daily intake of the US population ranges from 10-60 micrograms V. Vanadyl sulfate is a common supplement used to enhance weight training in athletes at doses up to 60 mg/d. In vitro and animal studies indicate that vanadate and other vanadium compounds increase glucose transport activity and improve glucose metabolism. In general, the toxicity of vanadium compounds is low. Pentavalent compounds are the most toxic and the toxicity of vanadium compounds usually increases as the valence increases. Most of the toxic effects of vanadium compounds result from local irritation of the eyes and upper respiratory tract rather than systemic toxicity. The only clearly documented effect of exposure to vanadium dust is upper respiratory tract irritation characterized by rhinitis, wheezing, nasal hemorrhage, conjunctivitis, cough, sore throat, and chest pain. Case studies have described the onset of asthma after heavy exposure to vanadium compounds, but clinical studies to date have not detected an increased prevalence of asthma in workers exposed to vanadium.

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, Na 2 CO 3, at about 850°C gives sodium vanadate, NaVO 3. 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, "V 2 O 5 ". Reduction of vanadium pentoxide with calcium, Ca, gives pure vanadium. An alternative suitable for small scales is the reduction of vanadium pentachloride, VCl 5, with hydrogen, H 2 , or magnesium, Mg. 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, "V 2 O 5 ", with crude iron. This produces ferrovanadium suitable for further work.
 * Isolation:**

Andres Manuel de Rio discovered it in 1801 while creating brown lead, and named it erythronium. In 1831, Nils Gabriel Stefstroem rediscovered it, and then it became an official element. In addition, in 1867, Henry E. Roscoe was the first person to completely isolate the metal (before this it hadn't been observed in its pure form).
 * History:**

Vanadium was first used as one of the components in the Ford Model T. It was, and still is used as a ferrovanadium or a steel additive. It significantly increases the strength in steel. Vanadium is compatible with iron and titanium, therefore vanadium foil is used in [|cladding] titanium to steel. [|[34]] The moderate [|thermal neutron-capture cross-section] and the short half-life of the isotopes produced by neutron capture makes vanadium a suitable material for the inner structure of a [|fusion reactor]. [|[35]] [|[36]] Several vanadium alloys show superconducting behavior. The first [|A15 phase] superconductor was a vanadium compound, V3Si, which was discovered in 1952. [|[37]] [|Vanadium-gallium] tape is used in [|superconducting] magnets (17.5 [|teslas] or 175,000 [|gauss] ). The structure of the superconducting A15 phase of V3Ga is similar to that of the more common [|Nb3Sn] and [|Nb3Ti]. All Vandaium compounds should be considered toxic. inhalation of vanadium can have a adverse affect on the respiratory system. 35 mg/m 3 of vanadium is considered extremely dangerous and exposure to this much of the chemical can cause serious health problems or death.
 * Applications:**
 * Toxicity:**

All vanadium compounds should be considered toxic. Tetravalent VOSO 4 has been reported to be over 5 times more toxic than trivalent V 2 O 3. 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. Vanadium compounds are poorly absorbed through the gastrointestinal system. Inhalation exposures to vanadium and vanadium compounds result primarily in adverse effects on the respiratory system. Quantitative data are, however, insufficient to derive a subchronic or chronic inhalation reference dose. Other effects have been reported after oral or inhalation exposures on blood parameters, on liver, on neurological development in rats, 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, although the interpretation of the results has recently been disputed. Vanadium has not been classified as to carcinogenicity by the United States Environmental Protection Agency. Vanadium traces in diesel fuels present a corrosion hazard; it is the main fuel component influencing high temperature corrosion. During combustion, it oxidizes and reacts with sodium and sulfur, yielding vanadate compounds with melting points down to 530 °C, which attack the passivation layer on steel, rendering it susceptible to corrosion. The solid vanadium compounds also cause abrasion of engine components.
 * Safety**

Vanadium metal is important in a number of areas. Its structural strength and neutron cross section properties makes it useful in nuclear applications. The metal is used for producing rust-resistant springs and steels used for making tools. About 80% of the vanadium now produced is used as ferrovanadium or as a steel additive. Vanadium foil is used as a bonding agent in biding titanium to steel The pentoxide V 2 O 5 is used in ceramics and as a chemical catalyst. Vanadium compounds are used for dyeing and printing fabrics. A vanadium-gallium mixture is used in producing superconductive magnets.
 * Uses**

Most vanadium is used as an alloy called ferrovanadium as an additive to improve steels. Ferrovanadium is produced directly by reducing a mixture of vanadium oxide, iron oxides and iron in an electric furnace. Vanadium-bearing magnetite iron ore is the main source for the production of vanadium. The vanadium ends up in pig iron produced from vanadium bearing magnetite. During steel production, oxygen is blown into the pig iron, oxidizing the carbon and most of the other impurities, forming slag. Depending on the used ore, the slag contains up to 25% of vanadium. Vanadium metal is obtained via a multistep process that begins with the roasting of crushed ore with NaCl or Na 2 CO 3 at about 850 °C to give sodium metavanadate (NaVO 3 ). An aqueous extract of this solid is acidified to give "red cake", a polyvanadate salt, which is reduced with calcium metal. As an alternative for small-scale production, vanadium pentoxide is reduced with hydrogen or magnesium. Many other methods are also in use, in all of which vanadium is produced as a byproduct of other processes. Purification of vanadium is possible by the crystal bar process developed by Anton Eduard van Arkel and Jan Hendrik de Boer in 1925. It involves the formation of the metal iodide, in this example vanadium(III) iodide, and the subsequent decomposition to yield pure metal. 2 V + 3 I 2 2 VI 3
 * Production**

Symbol: V Atomic Number: 23 Atomic Mass: 50.9415 amu Melting Point: 1890.0 °C (2163.15 K, 3434.0 °F) Boiling Point: 3380.0 °C (3653.15 K, 6116.0 °F) Number of Protons/Electrons: 23 Number of Neutrons: 28 Classification: Transition Metal Crystal Structure: Cubic Density @ 293 K: 5.8 g/cm3 Color: Silverish
 * Basic Properties:**

**Atomic Structure**

Isotopes

 * ** Isotope ** || ** Half Life ** ||
 * V-48 || 15.98 days ||
 * V-49 || 337.0 days ||
 * V-50 || 1.4E17 years ||
 * V-51 || Stable ||
 * V-52 || 3.76 minutes ||

Quick Facts

 * Date of Discovery:** 1830
 * Discoverer:** Nils Sefstrom
 * Name Origin:** After Vanadis (Scandinavian goddess)
 * Uses:** catalyst, dye, color-fixer
 * Obtained From:** minerals (patronite, vanadinite) (Examples of where one could find vanadium would be mainly in the Earth's crust. But also vanadium can be found in iron ores and phosphate rocks.)