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Zirconium (Zr)

QUICK REFERENCE

  • Symbol: Zr
  • Atomic Number: 40
  • Atomic Weight: 91.224
  • Element Classification: Transition Metal
  • Discovered By: Martin Heinrich Klaproth
  • Discovery Date: 1789
  • Name Origin: From the Persian ‘zargun’, meaning gold-colored; named after the mineral zircon
  • Density(g/cc): 6.52
  • Melting Point: 1855°C
  • Boiling Point: 4409°C
  • Appearance: Silvery white, lustrous metal
  • Atomic Radius(pm): 206

Discovery

Zirconium was discovered by German chemist Martin Heinrich Klaproth in 1789. Klaproth identified a new element in a sample of zircon (zirconium silicate, ZrSiO₄) from Ceylon (now Sri Lanka). He named the element zirconium after the mineral from which it was derived. However, it wasn’t until 1824 that Jöns Jakob Berzelius, a Swedish chemist, successfully isolated the pure metal. Zirconium’s name is derived from the Persian ‘zargun’, meaning gold-colored, referring to the color of the zircon crystals.

Relation to Other Elements

Zirconium is a transition metal, located in group 4 of the periodic table, between yttrium and niobium. It shares characteristics with its group neighbors, such as high melting points and a strong resistance to corrosion. Zirconium is similar to hafnium, which is found in the same ore and has almost identical chemical properties due to the lanthanide contraction. This makes the separation of zirconium and hafnium challenging. Zirconium is known for its excellent corrosion resistance, particularly in high temperatures and corrosive environments, which makes it valuable in various industrial applications.

Natural Occurrence

Zirconium is not found in nature as a free metal but is primarily obtained from the mineral zircon (ZrSiO₄), the most significant source of zirconium, and to a lesser extent from baddeleyite (ZrO₂). These minerals are mined in various parts of the world, including Australia, South Africa, and the United States. Zirconium is relatively abundant in the Earth’s crust and is more plentiful than copper and lead.

Uses

Zirconium’s unique properties have led to various applications:

  • Nuclear Reactors: Zirconium alloys, especially zircaloy, are used in nuclear reactors as cladding for fuel rods due to their low neutron absorption cross-section and good resistance to corrosion at high temperatures.
  • Ceramics and Refractories: Zirconium dioxide (zirconia, ZrO₂) is used in ceramics, dental implants, and refractory materials, prized for its high melting point, strength, and resistance to wear and thermal shock.
  • Chemical Industry: Zirconium compounds are used as catalysts in chemical reactions, including the production of synthetic materials and polymers.
  • Aerospace and Military: Due to its resistance to heat and corrosion, zircon

ium is used in aerospace and military applications for high-temperature components such as jet engine parts and in the manufacturing of some missile parts.

  • Biomedical Applications: Zirconia is used for making dental crowns and bridges, as well as hip replacements, because of its biocompatibility and mechanical properties.
  • Jewelry and Consumer Goods: Cubic zirconia (ZrO₂), a synthesized form of zirconium dioxide, is widely used as a diamond simulant in jewelry. Zirconium is also used in deodorants, anti-perspirants, and in some metal alloys for watches and camera lenses.

The discovery and subsequent utilization of zirconium have significantly impacted various industries, from nuclear energy to medical technology, highlighting the material’s versatility and the critical role of transition metals in advancing technological and industrial capabilities.

Yttrium (Y)

Niobium (Nb)