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| Atomic Number: | 21 | Atomic Symbol: | Sc | | Atomic Weight: | 44.9559 | Electron Configuration: | 2-8-9-2 | | Shells: | 2,8,9,2 | Filling Orbital: | 3d1 | | Melting Point: | 1539oC | Boiling Point: | 2832oC | | Uses: | stadium lighting |
History(L. Scandia, Scandinavia) On the basis of the Periodic System,
Mendeleev predicted the existence of ekaboron, which would have an atomic weight
between 40 of calcium and 48 of titanium.
The element was discovered by Lars Nilson in 1878 in the minerals euxenite
and gadolinite, which had not yet been found anywhere except in Scandinavia. By
processing 10 kg of euxenite and other residues of rare-earth minerals, Nilson
was able to prepare about 2g of highly pure scandium oxide. Later scientists
pointed out that Nilson's scandium was identical with Mendeleev's ekaboron.
SourcesScandium is apparently much more abundant (the 23rd most) in the
sun and certain stars than on earth (the 50th most abundant). It is widely
distributed on earth, occurring in very minute quantities in over 800 mineral
species. The blue color of beryl (aquamarine variety) is said to be due to
scandium. It occurs as a principal component in the rare mineral thortveitite,
found in Scandinavia and Malagasy. It is also found in the residues remaining
after the extraction of tungsten from Zinnwald wolframite, and in wiikite and
bazzite.
Most scandium is presently being recovered from thortveitite or is extracted
as a by-product from uranium mill tailings. Metallic scandium was first prepared
in 1937 by Fischer, Brunger, and Grienelaus who electrolyzed a eutectic melt of
lithium, and scandium
chlorides at 700 to 800C. zinc
served as the electrodes in a graphite crucible. Pure scandium is now produced
by reducing scandium fluoride with calcium metal.
The production of the first pound of 99% pure scandium metal was announced in
1960.
PropertiesScandium is a silver-white metal which develops a slightly
yellowish or pinkish cast upon exposure to air. A relatively soft element,
scandium resembles aluminum or aluminum, making it of interest to designers of spacecraft. Scandium
is not attacked by a 1:1 mixture of HNO3 and 48% HF.
CostsScandium oxide costs about $75/g.
UsesAbout 20 kg of scandium (as Sc2O3) are now being used yearly in the
U.S. to produce high-intensity lights, and the radiactive isotope 46Sc is used
as a tracing agent in refinery crackers for crude oil, etc.
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