metals

Zirconium

Building material for chemical plants

Zirconium, often zirconium, is a chemical element with the element symbol Zr and atomic number 40. Its name derives from zircon, the most common zirconium mineral. In the periodic table it is in the 5th period; it is the second element of the 4th group (obsolete 4th subgroup) or titanium group. Zirconium is a very corrosion resistant metal. Biological functions are unknown; it occurs in small amounts (4 mg/kg) in the human organism and is not toxic.[12]

An important use for zirconium is in the Zircaloy cladding of uranium fuel elements in nuclear power plants. This alloy consists of approx. 90% zirconium and small amounts of tin, iron, chromium or nickel, but must not contain any hafnium. The reason for choosing this element is the low capture cross-section for thermal neutrons described above, combined with high corrosion resistance, which also makes it suitable as a construction material for chemical plants, especially for special apparatus parts such as valves, pumps, pipes and heat exchangers. As an alloying addition to steel, it also increases corrosion resistance. Surgical instruments, among other things, are made from such alloys.

Since zirconium reacts with small amounts of oxygen and nitrogen, it can be used as a getter material in incandescent lamps and vacuum systems to maintain the vacuum. This property is also used in metallurgy to remove oxygen, nitrogen and sulfur from steel.