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Vanadium

DESIGNATIONS

CAS No.: 7440-62-2 1314-62-1
Registry name: Vanadium Vanadium pentoxide
Chemical name: Vanadium Vanadium pentoxide
Synonyms, Trade names: Vanadium Vanadium(V)oxide, divanadium pentoxide, vanadic acid anhydride, vanadic anhydride, vanadium pentaoxide
Chemical name German): Vanadium Vanadium pentoxid
Chemical name (French): Vanadium Pentoxyde de vanadium, anhydride vanadique, pentaoxyde de vanadium
Appearance: steely grey, ductile metal yellow to orange, crystalline powder or dark grey to brown lumps; odourless and tasteless

BASIC CHEMICAL AND PHYSICAL DATA

Empirical formula: V V2O5
Rel. molecular mass: 50.94 g 181.88 g
Density: 6.11 g/cm3 at 18.7C 3.357 g/cm3
Relative gas density:    
Boiling point: 3380C 1750C (decomposition)
Melting point: 1930C 690C
Flash point:   not combustible; promotes the combustion of other combustible substances
Solvolysis/solubility: insoluble in water, hydrochloric and sulphuric acid as well as in alkali lye at normal temperature, soluble in hydrofluoric and nitric acid 0.005 g/l at 20C in water, soluble in concentrated acids and lyes

ORIGIN AND USE

Usage:
Roughly 90% of vanadium compounds are used as alloying elements (80% in the form of ferrous vanadium and 9% as non-ferrous compounds in the aerospace industry). The pure metal serves as jacket material for nuclear fuel elements. Further use is as a catalyst, especially V2O5 in the production of sulphuric acid.

Origin/derivation:
Vanadium is found throughout the world and makes up 0.015% of the Earth's crust. The largest natural deposits are found in South Africa (42.2%), Russia (39.2%) and China (12.7%). Depending on location, the geogenic concentration in water fluctuates between 0.2 and 100 m g/l in freshwater and between 0.2 and 29 g/l in seawater. The ocean bed serves as a long-term sink. Natural deposits in coal and crude oil vary between 1 and 1500 mg/kg (WHO, 1987). It is estimated that some 65,000 t are released into the environment each year by natural emissions (volcanoes, etc.) and 200,000 t by human activities (chiefly in metalworking).

Production figures:

1979: 29,700 t acc. DVGW, 1985
1981: 35,000 t acc. WHO, 1987
1980-84: 34-46,000 t acc. WHO, 1988
1984 33,300 t acc. RMPP, 1988

The principal producers are Chile, Finland, Namibia, Norway, South Africa, Russia and the USA.

Toxicity

Vanadium pentoxide:
Mouse LD50 23.4 mg/kg, oral acc. WHO, 1988
Rat LC50 70 mg/m3, inhalation acc. WHO, 1988
Rat LD 10 mg/kg, oral acc. WHO, 1988
Cat LC50 500 mg/m3, inhalation acc. WHO, 1988
Rabbit LC 205 mg/m3, inhalation acc. WHO, 1988
Ammonium vanadate:
Mouse LD50 10 mg/kg, oral acc. WHO, 1988
Vanadium trichloride:
Mouse LD50 24 mg/kg, oral acc. WHO, 1988
Vanadium dibromide:
Mouse LD50 88 mg/kg, oral acc. WHO, 1988
Vanadium sulphate:
Rat LD 10 mg/kg, oral acc. WHO, 1988
Rabbit LD50 59.1 mg/kg, subcutaneous acc. WHO, 1988
Guinea pig LD 800 mg/kg, subcutaneous acc. WHO, 1988
Guinea pig LD50 560 mg/kg acc. WHO, 1988

Characteristic effects:

Humans/mammals: Vanadium pentoxide irritates the skin and mucous membranes (0.1 mg/m3 after 8 hours) and acts as a blood, liver and kidney poison. Symptoms of chronic exposure are bronchitis, pneumonia, anaemia, liver and kidney damage (concentrations of 0.1 - 0.4 mg/m3 during 10 years may result in changes in the nasal mucous membranes, chronic bronchitis and discolouration of the tongue; acc. HORN, 1989). The effect depends on the particle size: aerosols > 5 m m cannot penetrate the lungs. 40-60% are excreted via the kidneys after 1-3 days with 10-12% being excreted via the intestines. Vanadium pentoxide inhibits enzymes and prevents the synthesis of ascorbic and fatty acids in addition to affecting DNA (HORN, 1989).

ENVIRONMENTAL BEHAVIOUR

Water:
Vanadium compounds are denser than water and sink to the bottom. Vanadium pentoxide slowly dissolves in a large volume of water and forms toxic mixtures. Vanadium trichloride, vanadium tetrachloride and vanadium oxytrichloride react with water when exposed to heat to form toxic and irritating hydrochloric acid vapours which in turn form a white mist over the water surface.

Air:
The atmosphere represents a transport medium. Vanadium pentoxide is a reactive solid which promotes the combustion of other combustible substances. Vanadium trichloride forms toxic mixtures in air which decompose vigorously in contact with moisture and form corrosive hydrogen chloride. Decomposition to chlorine gas or hydrogen chloride gas occurs at high temperatures. Vanadium tetrachloride and vanadium oxytrichloride are corrosive, non-combustible liquids, which, when exposed to heat, likewise form corrosive mists made up of vanadium pentoxide, hydrogen chloride gas or hydrochloric acid. These are denser than air and creep along the ground. Vanadium tetrachloride reacts vigorously in water to form corrosive vanadium trichloride, vanadium oxytrichloride and hydrochloric acid.

Soil:
Vanadium compounds are geogenic and ubiquitous. Vanadium is an essential trace element whose compounds are absorbed by plants and incorporated into their growth process. Vanadium thus finds its way from the soil into the food chain.

Degradation, decomposition products, half-life:
When exposed to light and heat, most vanadium compounds decompose to form corrosive vapours or gases. Contact with water usually produces vigorous reactions in which corrosive vapours and gases are likewise formed.

Food chain:
Plants and animals incorporate vanadium as an essential trace element. The daily intake with foodstuffs is estimated at 100 m g for humans with most of the vanadium being excreted again without resorption.

ENVIRONMENTAL STANDARDS

Medium/
acceptor
Sector Country/organ. Status

Value

Cat. Remarks Source
Water: Surface D

G

0.05 mg/l

  For treatment (DVGW, 1985)
Irrigation USA  

10 mg/l

  Short-time value (DVGW, 1985)
Soil:   D G

50 mg/kg

    (KLOKE, 1988)
Air: Emiss. D L

5 mg/m3

  mass flow > 25 g/h1) acc. TA Luft, 1986
  DDR (L)

0.002 mg/m3

  V2O5, long-time value acc. HORN et al., 1989
Workp AUS (L)

0.05 mg/m3

  V2O5 (smoke) acc. MERIAN, 1984
Workp B (L)

0.05 mg/m3

  V2O5 (smoke) acc. MERIAN, 1984
Workp D L

0.05 mg/m3

MAK V2O5 (fine dust) acc. BAUM, 1988
Workp CH (L)

0.1 mg/m3

  V2O5 (smoke) acc. MERIAN, 1984
Workp CS (L)

0.1 mg/m3

  V2O5 (smoke), average acc. MERIAN, 1984
Workp CS (L)

0.3 mg/m3

  V2O5 (smoke), short term acc. MERIAN, 1984
Workp CS (L)

1.5 mg/m3

  Dust acc. WHO, 1988
Workp DDR (L)

0.1 mg/m3

  V2O5 (smoke) acc. HORN et al., 1989
Workp DDR (L)

0.5 mg/m3

  V2O5 (dust), short time acc. HORN et al., 1989
Workp DDR (L)

0.002 mg/m3

  V2O5 (dust), long time acc. HORN et al., 1989
Workp H (L)

0.1 mg/m3

  V2O5 (smoke) acc. WHO, 1988
Workp I G

0.015 mg/m3

  V2O5 (smoke) acc. MERIAN, 1984
Workp J (L)

0.1 mg/m3

  V2O5 (smoke) acc. MERIAN, 1984
Workp NL (L)

0.05 mg/m3

  V2O5 (smoke) acc. WHO, 1988
Workp RO (L)

0.1 mg/m3

  V2O5 (smoke), short time acc. WHO, 1988
Workp S (L)

0.5 mg/m3

  V2O5 (dusts) acc. ACGIH, 1982
Workp S (L)

0.05 mg/m3

  V2O5 (smoke) acc. MERIAN, 1984
Workp SF (L)

0.05 mg/m3

  V2O5 (smoke) acc. MERIAN, 1984
Workp SU (L)

0.002 mg/m3

  24 h, V2O5 acc. STERN, 1986
Workp SU (L)

0.1 mg/m3

  V2O5 (smoke) acc. MERIAN, 1984
Workp SU (L)

0.5 mg/m3

  V2O3 acc. KETTNER, 1979
Workp USA (L)

0.05 mg/m3

TWA V2O5 (smoke/ dusts) acc. ACGIH, 1986
Workp YU (L)

0.1 mg/m3

  V2O5 (smoke) acc. WHO, 1988

Note:
Limit and approximate values generally exist for the sum total of all vanadium compounds and are given in V2O5
1) dustlike V and its compounds, stated as V

Comparison/reference values

Medium/origin Country Value Source
Water:
Lake Constance (berlingen, 1973-74)   1.1-1.9 g/l acc. DVGW, 1985
Rhine (Mannheim, 1971-74)   0.9-11.6 g/l acc. DVGW, 1985
Rhine (Mainz, 1971-74)   1.6- 3 g/l acc. DVGW, 1985
Rhine (Wiesbaden, 1971-74)   0.1-10.3 g/l acc. DVGW, 1985
Main (Ottendorf, 1971-73)   0.2-9.6 g/l acc. DVGW, 1985
Main (Kostheim, 1971-73)   0.9-16 g/l acc. DVGW, 1985
Ruhr (Echthausen, 1983)   0.2-1.2 g/l acc. DVGW, 1985
Seawater   0.2-29 g/l acc. DVGW, 1985
Drinking water (USA, 1962, 100 cities)   n.d.--70 g/l acc. DVGW, 1985
Soil/sediment:
Various soils (mean)   100 mg/kg acc. DVGW, 1985
Various soils   1-680 mg/kg acc. WHO, 1988
Coal (mean)   30 mg/kg acc. DVGW, 1985
Oil (mean)   50 mg/kg acc. DVGW, 1985
Air:
South Pole   0.001-0.002 ng/m3 acc. WHO, 1988
Rural areas CDN 0.21-1.9 ng/m3 acc. WHO, 1988
Outdoors   0.02-13 m g/m3 V2O5 acc. HORN, 1989
Animals:
Molluscs   0.7 mg/kg acc. WHO, 1988
Crustaceans   0.4 mg/kg acc. WHO, 1988
Insects   0.15 mg/kg acc. WHO, 1988
Fish   0.14 mg/kg acc. WHO, 1988
Mammals   0.4 mg/kg acc. WHO, 1988

Assessment/comments

There are still no clear-cut results on the effects of the majority of vanadium compounds. Therefore, attempts should be made to avoid any possible impacts caused by them.


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