VANADIUM
- Atomic Number: 23
- Atomic Symbol: V
- Atomic Weight: 50.9414
- Electron Configuration: -8-11-2
History:
-
(Scandinavian goddess, Vanadis) 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 chemists'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 1922.
Vanadium is found in about 65 different minerals among which are
carnotite, 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 ask hold promise as an important
source of the leement. 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 Seybair. Natural
vanadium is a mixture of two isotopes, 50V (0.24%) and 51V (99.76%).
50V is slightly radioactive, having a half-life of > 3.9 x 10^17
years. Nine other unstalbe 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 660C. 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, srping, and highspeed tools 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 ued in producing a superconductive magnet with a field of
175,000 gauss. Vanadium and its compounds are toxic and should be
handled with care. the maximum allowable concentration of V2O5 dust
in air is about 0.05 (8-hour time-weighted average - 40-hour week).
Ductile vanadium is commercially available. Commercial vanadium
metal, of about 95% purity, costs about $20/lb. Vanadium (99.9%)
costs about $100/oz.
Source: CRC Handbook of Chemistry and Physics, 1913-1995. David R. Lide, Editor in Chief. Author: C.R. Hammond
Copyright ©1995-1998
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