Zirconium

Zirconium, chemical element, symbol Zr; for physical constants, see Periodic Table. Zirconium is mentioned in biblical writings as the mineral zircon. In 1789 Martin Heinrich Klaproth isolated the oxide of zirconium from zircon. The impure metal was first isolated by Jöns J. Berzelius in 1824. Zircon (zirconium silicate) is the principal ore of zirconium. Zirconium is produced commercially by reduction of the chloride with magnesium. It is a grayish-white, lustrous metal resistant to corrosion by acids, alkalis, sea water, and other agents. It is superconductive at low temperatures. The metal has a low absorption cross section for neutrons. Most zirconium is used in nuclear reactors. Zirconium oxide is a refractory material and is used in furnaces and in the glass and ceramic industries.