Zirconium
Zirconium was first isolated by Jöns Jakob Berzelius, a Swedish chemist, in 1824. Zirconium got its name from the Persian word zargun, meaning gold-like. It is never found as a native metal, but is instead obtained mainly from the minerals zircon and baddeleyite.
Zirconium is a lustrous, very strong, malleable, ductile, silver gray metal. It is solid at room temperature, though it becomes hard and brittle at lower purities. Lighter than steel, its hardness is similar to copper, and it is extremely resistant to heat and corrosion by alkalis, acids, salt water and other agents. It will dissolve in hydrochloric and sulfuric acid, especially when fluorine is present. When it is finely divided, it can spontaneously ignite in air.
Applications of Zirconium:
- Energy: Ninety per cent of all zirconium produced is used in nuclear reactors because of its low neutron-capture cross-section and resistance to corrosion. It is the primary component in the zirconium aluminum alloy zircaloy.
- Science and Medical: Zirconium is often used as an alloying agent in materials that are exposed to corrosive agents because of zirconium's resistance to corrosion (e.g. surgical appliances, explosive primers, vacuum tube getters, filaments, performance pumps and valves). Zirconium dioxide, or zirconia, is used in laboratory crucibles, metallurgical furnaces and as a refractory material. Zirconium is a component in some abrasives, such as grinding wheels and sandpaper. It is also used as a hardening agent in alloys, especially steel, and in catalytic converters and percussion caps. Stabilized zirconia is used for surgically implanted artificial joints. Zirconium alloys are used in space vehicle parts for their resistance to heat: an important quality given the extreme heat associated with atmospheric re-entry.
- Jewellery: Zircon is faceted into gemstones for use in jewellery.
See Also: