Zirconium is a hard, lustrous, silvery coloured metal which is extracted from its ores (the oxide or zircon, ZrSiO4) by conversion to the tetrahalide followed by reduction with magnesium. The metal is extremely corrosion resistant due to the formation of a stable oxide film and is unaffected by acids (with the exception of HF) and alkalis. As a result of its corrosion resistance, zirconium is widely used in the chemical industry where corrosive agents are used. Also, due to its excellent high temperature properties, coupled with its low neutron absorption, it is used in the construction of nuclear reactors. The pure metal is also used as a lining in jet engines. Zirconium is used as an alloying element, the resultant alloys having improved mechanical properties. The chemical properties of zirconium are very similar to those of hafnium. As a result, the normal chemical processes used for the extraction of zirconium will not remove hafnium, which can be present in commercial grades of zirconium at levels as high as 4.5%.
- Berlin, Germany, in 1789 by M.H. Klaproth, but was not isolated until 1824 by J.J. Berzelius in Stockholm, Sweden.
|Atomic / Molecular Weight||91.224||gmol-1||Clip|
|Crystal Structure||hcp / bcc at 1100K||Clip|
|Tensile strength||260e6 (annealed) 1e9 (hard drawn)||Nm-2||Clip|
|Specific heat capacity||276||Jkg-1K-1||Clip|
|Acoustic wave velocity (longitudinal bulk waves)||4650||ms-1||Clip|
|Acoustic wave velocity (Shear waves)||2250||ms-1||Clip|