Home - Periodic Tables
For zircon gemstone.
(Persian zargun, gold like) The name zircon probably originated from the Persion word
zargun, which describes the color of the gemstone now known as zircon, jargon, hyacinth,
jacinth, or ligure. This mineral, or its variations, is mentioned in biblical writings.
The mineral was not known to contain a new element until Klaproth, in 1789, analyzed a
jargon from from Ceylon and found a new earth, which Werner named zircon (silex
circonius), and Klaproth called Zirkonertz (zirconia). The impure metal was first isolated
by Berzelius in 1824 by heating a mixture of potassium and potassium zirconium fluoride in
a small decomposition process they developed.
Zirconium is found in abundance in S-type stars, and has been identified in the sun and
meteorites. Analysis of lunar rock samples obtained during the various Apollo missions to
the moon show a surprisingly high zirconium oxide content, compared with terrestrial
Naturally occurring zirconium contains five isotopes. Fifteen other isotopes are known
to exist. Zircon, ZrSiO4,
the principal ore, is pure ZrO2
in crystalline form having a hafnium content of about 1%. Zirconium also occurs in some 30
other recognized mineral species. Zirconium is produced commercially by reduction of
chloride with magnesium (the Kroll Process), and by other methods. It is a grayish-white
lustrous metal. When finely divided, the metal may ignite spontaneously in air, especially
at elevated temperatures. The solid metal is much more difficult to ignite. The inherent
toxicity of zirconium compounds is low. Hafnium is invariably found in zirconium ores, and
the separation is difficult.
Commercial-grade zirconium contains from 1 to 3% hafnium. Zirconium has a low
absorption cross section for neutrons, and is therefore used for nuclear energy
applications, such as for cladding fuel elements. Commercial nuclear power generation now
takes more than 90% of zirconium metal production. Reactors of the commercial size, now
being made, may use as much as a half-million linear feet of zirconium alloy tubing.
Reactor-grade zirconium is essentially free of hafnium. Zircaloy(R) is an important
alloy developed specifically for nuclear applications. Zirconium is exceptionally
resistant to corrosion by many common acids and alkalis, by sea water, and by other
agents. Alloyed with zinc, zirconium becomes magnetic at temperatures below 35oK.
It is used extensively by the chemical industry where corrosive agents are employed.
Zirconium is used as a getter in vacuum tubes, as an alloying agent in steel, in surgical
appliances, photoflash bulbs, explosive primers, rayon spinnerets, lamp filaments, etc. It
is used in poison ivy lotions in the form of the carbonate as it combines with urushiol.
With niobium, zirconium is superconductive at low temperatures and is used to make
superconductive magnets, which offer hope of direct large-scale generation of electric
power. Zirconium oxide (zircon) has a high index of refraction and is used as a gem
material. The impure oxide, zirconia, is used for laboratory crucibles that will withstand
heat shock, for linings of metallurgical furnaces, and by the glass and ceramic industries
as a refractory material. Its use as a refractory material accounts for a large share of
all zirconium consumed.
Zirconium of about 99.6% purity is available at a cost of about $150/kg.
Sources: CRC Handbook of Chemistry
and Physics and the American Chemical Society.
[an error occurred while processing this directive]