Chemical Fact Sheet
Vanadium
| Chemical Abstract Number (CAS #) | 7440-62-2 |
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| Analytical Methods | 200.7 - 200.8 - 6010 - 6020 |
| Molecular Formula | V |
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Synopsis
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Vanadium - (Scandinavian goddess, Vanadis), V; at. wt. 50.9415(1); at. no. 23; m.p. 1910 +/- 10 deg C; b.p. 3407 deg C; sp. gr. 6.11 (18.7 deg C); valence 2, 3, 4, or 5. Vanadium was first discovered by del Rio in 1801. Unfortunately, a French chemist incorrectly declared del Rio's new element was only impure chromium; del Rio thought himself to be mistaken and accepted the French chemist's statement. The element was rediscovered in 1830 by Sefstrom, who named the element in honor of the Scandinavian- goddess Vanadis because of its beautiful multicolored compounds. It was isolated in nearly pure form by Roscoe, in 1867, who reduced the chloride with hydrogen. Vanadium of 99.3 to 99.8% purity was not produced until 1927. Vanadium is found in about 65 different minerals among which are camotite, roscoelite, vanadinite, and patronite important sources of the metal. Vanadium is also found in phosphate rock and certain iron ores, and is present in some crude oils in the form of organic complexes. It is also found in small percentages in meteorites. Commercial production from petroleum ash holds promise as an important source of the element. High-purity ductile vanadium can be obtained by reduction of vanadium trichloride with magnesium or with magnesium-sodium mixtures. Much of the vanadium metal being produced is now made by calcium reduction Of V2O5 in a pressure vessel, an adaption of a process developed by McKechnie and Seybolt. Natural vanadium is a mixture of two isotopes, 50V (0.25%) and 51V (99.75%). 50V is slightly radioactive, having a long half-life. Seventeen other unstable isotopes are recognized. Pure vanadium is a bright white metal, and is soft and ductile. It has good corrosion resistance to alkalis, sulfuric and hydrochloric acid, and salt water, but the metal oxidizes readily above 660 deg C. The metal has good structural strength and a low fission neutron cross section, making it useful in nuclear applications. Vanadium is used in producing rust resistant, spring, and highspeed tool steels. It is an important carbide stabilizer in making steels. 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 cladding titanium to steel. Vanadium pentoxide is used in ceramics and as a catalyst. It is also used in producing a superconductive magnet with a field of 175,000 gauss. Vanadium and its compounds are toxic and should be handled with care. Ductile vanadium is commercially available. Commercial vanadium metal, of about 95% purity, costs about $50kg. Vanadium metal (99.7%) costs about $1.50/g or $700/kg. |
| Use | The principal use of vanadium is as an alloying addition to iron & steel, particularly in high strength steels &, to a lesser extent, in tool steels & castings. In the production of aerospace titanium alloys. TARGET MATERIAL FOR X-RAYS, VANADIUM CMPD, ESPECIALLY CATALYSTS FOR SYNTHETIC RUBBER In producing rust resistant, spring, & high speed tool steels. It is an important carbide stabilizer in making steels. Vanadium foil is used as a bonding agent in cladding titanium to steel. COMPONENT OF MICROSTRUCTURE & GAS CONTENT CONTROLLER IN COPPER ALLOYS; STRENGTH ENHANCER & HEAT RESISTOR IN ALUMINUM ALLOYS; COMPONENT OF OTHER ALLOYS-EG, PERMANENT MAGNET ALLOYS; CATALYST IN CERTAIN PETROCHEMICAL REACTIONS; COMPONENT OF INSTRUMENTS FOR EXPERIMENTAL PROGRAMS Interest in the intermetallic compound V3Ga for superconductor applications could lead to expanded use /of vanadium/ in the future. During the 1970s, vanadium alloys were considered for use as cladding material for the fuel in liquid metal cooled fast reactors. However, most development programs involving vanadium for this purpose have been reduced because of insufficient funding. |
| Consumption Patterns | COMPONENT OF FERROVANADIUM ALLOY, 87%; OTHER USES (INCL IN ALLOYS & AS METAL), 13% (1982) Major end use distribution was as follows: machinery & tools, 36%; transportation, 27%; building and heavy construction, 25%; and other, 12% (1988) Increased demand for vanadium products came mostly from the steel industry which had the highest 1st half shipments since 1980. Although all major steel consuming sectors increased purchases, the oil & gas industry reported the biggest change, up more than 120% from the same period in 1987. The extraordinary demand for vanadium created shortages of vanadium raw materials (1988). |
| Apparent Color | LIGHT GRAY OR WHITE LUSTROUS POWDER, FUSED HARD LUMPS OR BODY-CENTERED CUBIC CRYSTALS ; Pure vanadium is a bright white metal |
| Boiling Point | 3380 DEG C |
| Melting Point | 1917 DEG C |
| Molecular Weight | 50.9415 |
| Density | 6.11 AT 18.7 DEG C |
| Sensitivity Data | Extensive evidence exists that vanadium dust (usually the pentoxide) is severely irritating to the mucous membranes of the eyes, nose, throat and respiratory tract. Vanadium is a primary irrtant to the skin. |
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Chemical and Physical Properties |
TWO NATURALLY OCCURRING ISOTOPES: (51)V (99.75%): (50)V (0.25%); THE LATTER IS RADIOACTIVE: T1/2 6X10+15 YEARS; ARTIFICIAL ISOTOPES: 46-49; 52-54 PRECIPITATES GOLD, SILVER & PLATINUM FROM THEIR SALTS; REDUCES MERCURIC SALTS TO MERCUROUS, FERRIC SALTS TO FERROUS; NOT ATTACKED BY BROMINE WATER, OR BY COLD SULFURIC ACID Vanadium is resistant to attack by hydrochloric or dilute sulfuric acid & to alkali solutions. It is also quite resistant to corrosion by seawater but is reactive toward nitric, hydrofluoric, or concn sulfuric acids. Galvanic corrosion tests run in simulated seawater indicate that vanadium is anodic with respect to stainless steel & copper but cathodic to aluminum & magnesium. Vanadium exhibits corrosion resistance to liquid metals, eg, bismuth & low oxygen sodium. FORMS AN ALLOY WITH FE (FERROVANADIUM) IN WHICH THERE IS COMPLETE LIQUID SOLUBILITY; FORMS A VERY HARD AND STABLE CARBIDE, V4C3 IN CARBON AND MOST ALLOY STEELS. ACTS AS METAL OR NONMETAL; VALANCES 2, 3, 4, 5 When heated in air at different temperatures, it oxidizes to a brownish black trioxide, a blue black tetraoxide, or a reddish orange pentoxide. It reacts with chlorine at fairly low temperatures (180 deg C) forming vanadium tetrachloride & with carbon & nitrogen at high temperatures forming VC & VN, respectively. The pure metal in massive form is relatively inert toward oxygen, nitrogen, & hydrogen at room temperature. Lattice constant, 0.3026 nm; specific heat, 0.50 J/g at 20-100 deg C; latent heat of fusion, 16.02 kJ/mol; enthalpy, 5.27 kJ/mol at 25 deg C; entropy, 29.5 kJ/mol deg C at 25 deg C; thermal conductivity, 0.31 W/cm deg K at 100 deg C; electrical resistance, 24.8-26.0 microohm cm at 20 deg C; recrystallization temp, 800-1000 deg C; modulus of elasticity, (1.2-1.3)X10+5 MPa Pure vanadium is soft & ductile. Vanadium has good structural strength & a low fission neutron cross section, making it useful in nuclear applications. |
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Environmental Impact |
Occupational exposure to vanadium containing dusts is encountered in the mining of vanadium bearing ores. Most of the vanadium bearing ores in the United States come from Arkansas, Colorado, and Idaho while foreign sources include South Africa, Chile, and the USSR. In milling, exposure to vanadium containing dust can occur near the production sites of numerous vanadium compounds, particularly vanadium pentoxide and, to a lesser extent, the vanadates. Numerous exposures to vanadium compounds have occurred during the cleaning of oil fired burners, where the dust is generated from the residual oil ash of high vanadium content oil. Vanadium is present in all fuel oils & it remains in the residue after the more volatile fractions have been distilled. After combustion it appears as the pentoxide, which, when mixed with water, forms an acid solution irritating to the skin & eyes. The men who clean oil fired boilers & combustion chambers & the bricklayers who renew the firebrick linings are exposed to large amounts of dust, containing 6.1 to 12.7% of vanadium while those who clean the deposit on the outside of the heat exchanger tubes of gas turbines may be exposed to dust containing from 11-20% of vanadium. The toxic effects of vanadium in industry have occurred mainly through inhalation; possibly, though to a lesser extent, from ingestion of the pentoxide, sulfate or mixed vanadium dust. The exposure has usually occurred during the cleaning of oil fired burners or gas turbines, but has also been noticed in the extraction process of vanadium from vanadium containing ores; one of the earliest of these observations was published in 1911, but the conclusions have not been universally confirmed. |
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Environmental Fate |
It usually occurs in some oxidized form usually as a metal vanadate. Vanadium can also be found in trace amounts in fossil fuels. Vanadium does not occur in highly concentrated forms. This is true despite the fact that it is as abundant in the earth's crust as zinc & nickel & occurs in at least 50 different mineral species. Although ores containing small amounts of vanadium are rather widely distributed throughout the world, the most important ones are found in the Western Hemisphere. During the 1970s domestic USA sources (mine production & recovery) have been largely confined to four states, Colorado, Arkansas, Idaho, & Utah. The chief vanadium ores in uranium bearing sandstones are carnotite (K2O.2UO3.V2O5.3H2O), roscoelite (CaO.3V2O5.9H2O), & vanadinite (Pb(PbCl)(V2O4)). In all, more than 65 vanadium ores have been described, but all except 5 or 6 are of secondary origin formed by oxidation or weathering. Other potential sources are weathered shale, 1% vanadium pentoxide, & oil crudes, up to 3.72 ug vanadium/ml. Most of the approximately 20 primary vanadium-bearing minerals have been found in Canada while only a few of the secondary minerals occur. The primary minerals are generally associated with basic igneous rock, basic alkaline igneous rock, carbonatite complexes, titaniferous magnetite complexes and chromite, uranium, iron and manganese deposits. Vanadium, is present in coal and crude oil. Six samples of Albertan coal from various locations had an average vanadium content of 0.01% (100 mg/kg). One sample of Nova Scotia coal contained 0.08% (800 mg/kg) vanadium while the ash from six British Columbia coal samples contained an average of 0.04% (400 mg/kg) vandium. The weighted average of vanadium in USA coal is 25 mg/kg. In contrast, natural gas contains less than 50 mg V/kg. Petroleum & other naturally occurring hydrocarbons such as asphaltite contain appreciable quantities of vanadium. Vanadium does not occur naturally in highly concentrated forms. This is true despite the fact that it is as abundant in the earth's crust as zinc & nickel & occurs in at least 50 different mineral species. It usually occurs in some oxidized form usually as a metal vanadate. Vanadium can also be found in trace amounts in fossil fuels. Although ores containing small amounts of vanadium are rather widely distributed throughout the world, the most important ones are found in the Western Hemisphere. During the 1970s domestic USA sources (mine production & recovery) have been largely confined to four states, Colorado, Arkansas, Idaho, & Utah. The chief vanadium ores in uranium bearing sandstones are carnotite (K2O.2UO3.V2O5.3H2O), roscoelite (CaO.3V2O5.9H2O), & vanadinite (Pb(PbCl)(V2O4)). In all, more than 65 vanadium ores have been described, but all except 5 or 6 are of secondary origin formed by oxidation or weathering. Other potential sources are weathered shale, 1% vanadium pentoxide, & oil crudes, up to 3.72 ug vanadium/ml. A principal ore is patronite. The major point sources of atmospheric emission are metallurgical works (30 kg vanadium/ton vanadium produced), & oil & coal burning (0.2 to 2 kg/1000 tons & 30-300 kg/1X10+6 liters, respectively). Fossil fuel combustion is the largest source of air pollution by vanadium, partly as a result of the limited use of efficient flue gas cleaning. One kind of pollution from vanadium must be noted when considering water. Residues from the milling & mining of vanadium are often heaped on the ground or used as landfills, thus being exposed to rainfall & groundwater drainage, which could result in water pollution for many miles around. A relatively large amount of vanadium (some 30,000 metric tons/yr) enters the environment from man's activities, but no widespread detrimental effects have been identified. Vanadium concn in food reported in the literature differ widely. In older studies, the values are usually considerably higher than in more recent ones. As an example in a 1963 report a colorimetric method demonstrated 1.5 mg/kg (wet wt) in potatoes, whereas reports published in the late seventies using AAS or NAA gave concn ranging from 1 to 6 ug/kg. Similar variations exist for other vegetables & fruits, but are not so great.Concn in meat are approx 1 ug/kg. It is likely that vanadium concn in common food do not exceed a few ug/kg. Determination of vanadium content of selected foods showed that beverages, fats, oils, & fresh fruit & vegetables contained the least vanadium ranging from <0.001 to 0.005 mg/kg. Grains, seafood, meats, & dairy products were generally within the range of 0.005 to 0.03 mg/kg, prepared food within 0.011 to 0.093 mg/kg, while dill seed & black pepper contained 0.431 & 0.987 mg vanadium/kg, respectively. The aerial portions of most plants are not correlated to soil vanadium levels. Mean concn in higher plants were found to be 0.16 mg vanadium/kg (fresh wt). In freshwater plants concn of 0.4 to 80 mg vanadium/kg were reported with the maximum value accumulated by the pickerel weed (Pontedaris cordata). In cow milk, vanadium was found at levels from about 0.2 ug/kg (wet wt) according to a 1978 report to 10 ug/kg according to a 1963 report. The concentration of vanadium in human milk was determined to be 0.1-0.2 ng/g. An infant ingesting 1 liter of milk per day would thus have a daily intake of 0.1-0.2 ug vanadium (assumes 1 l milk weighs 1 kg). Inhalation is the main pathway of exposure in the work environment (production of vanadium & its compounds, boiler cleaning). Exposure of the general population by way of food & air is low. Estimated average daily dietary intake of the metal is 20 ug. The 2 mg estimated to be the daily average intake of vanadium is probably incorrect. Other studies have been conducted which provide reasonable suggestions concerning the typical daily dietary intake by humans. The vanadium content of nine institutional diets were ascertained and it was found that they would supply 12.4 to 30.1 ug of vanadium daily (average, 20 ug). from these studies it is concluded that "It can be estimated that the daily dietary intake is of the order of a few tens of micrograms, though it may vary over wide limits". Assuming that 20 cu m is inhaled daily, ambient air would contribute 0.2% to 6% to the total daily intake of vanadium in some regions & cities in the USA. In some eastern cities, ambient air would contribute as much or more vanadium as the typical diet. However, in regions other than the eastern US, ambient air would contribute probably less than 0.1% to the total daily intake of vanadium. Assuming a daily intake of 2 liters of water, data indicate that typical drinking water sources would contribute between negligible amounts & 140 ug of vanadium daily. The average contribution is probably near 8 ug of vanadium daily which would be 40% of the amount of vanadium derived from ususal dietary source. In some instances, the contribution of drinking water to the daily intake of vanadium may be much greater than the contribution of the diet. For example, if the drinking water contained 33 ug of vanadium per liter, it would contribute 3 times as much vanadium as a typical diet. It is estimated that the total body content of vanadium in healthy, adults humans is approx 100 ug. The vanadium concentration in lung, pulmonary lymph nodes, blood, and urine of coal miners (USA) all show values well elevated above corresponding samples from resident nonminers, and far above those from individuals living away from such sources. Content in coal miners lungs ranged from 9.9 to 99 ug vanadium/g; pulmonary lymph nodes values were from 20 to 43 ug/g, compared to lungs of nonminers residing in the area of 0.7 to 11 ug/g, and with the highest lung values among residents of USA cities, less than 0.01 to 0.95 ug vanadium/g. The concentration of vanadium in human milk was determined to be 0.1-0.2 ng/g. An infant ingesting 1 litre of milk per day would thus have a daily intake of 0.1-0.2 ug vanadium (assumes 1 l milk weighs 1 kg). A survey was made in five countries of the levels of 21 trace elements in human fingernails. More than 500 samples from Japan, India, Poland, Canada, and the United States were analyzed, and possible geographic, age, or sex differences were explored. Trace elements included, vanadium. Only trace or subtrace levels (0.05 to 5 ppm) were found for some elements including vanadium. Vanadium levels decreased with increasing age in both males and females. Use of tin coated iron and aluminum cookware was probably responsible for higher levels of aluminum and iron in Indian samples. Nonsmokers had higher levels of manganese in Japan and of selenium in Canada, Poland, and the United States. Results suggest that significant differences occur in trace element distributions for populations of different origin, and a survey such as this can be useful in establishing the impact of dietary and living habits on trace element distribution in devitalized human tissues. |
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Disposal |
At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices. Waste material contaminated with vanadium shall be disposed of in a manner not hazardous to employees. The disposal method must conform with applicable local, state, and federal regulations and must not constitute a hazard to the surrounding population or environment. The following wastewater treatment technologies have been investigated for vanadium: Concentration process: chemical precipitation. |
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Atmosphere |
Background vanadium concentrations in unpolluted air range from 0.02 to 2.0 ng V/cu m. Rural sites may have vanadium levels as high as 65 ng V/cu m (average range <1-40 ng/cu m) while industrialized urban centers with a high consumption of residual fuel oil may have maximum levels up to 10,000 ng V/cu m (average range 500-2000 ng/cu m). Occupational exposure to vanadium may involve exposure to mg/cu m levels of vanadium or roughly 106 times the background level. |
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