Zirconium, the metal extracted from the mineral, zircon, may not be well-known, but its remarkable properties make it indispensable in nuclear power, the chemical industry, medicine and more. Since ancient times, zircon - a word believed to have originated from the Persian zargun, meaning gold-like - has been used in jewellery and decorations.
1. Zirconium is a shiny silver-grey metal
It is highly ductile and extremely resistant to corrosion and heat. Its symbol in the periodic table is Zr, and its atomic number is 40. It melts at 1855 degrees Celsius (°C) and boils at 4409 °C, and it is not corroded by acids, alkalis or seawater.
2. The mineral zircon is relatively widespread on the Earth's surface
Zirconium is primarily extracted from the mineral zircon which is often found in the sands of coastal waters. The mineral is not contained in concentrated deposits, but rather broadly dispersed inside the ground. Today, the major producers of zirconium include Australia, China, Indonesia, South Africa and Ukraine. Beyond Earth, the element has been identified in the stars, including the Sun, and in lunar rocks.
3. Zirconium was discovered in 1789
Zirconium was identified by German chemist Martin Klaproth in a zircon stone brought from Sri Lanka. Pure zirconium - metal not mixed or alloyed with other elements - was first produced in 1925. But it was not widely used in industry until the end of the 1940s when it became an important engineering material used in producing nuclear energy.
4. Zirconium is mainly used in nuclear power
Zirconium is indispensable in the production of nuclear energy, particularly as a cladding for long cylindrical fuel rods inside nuclear reactors. There are several reasons why zirconium is an optimal material to surround uranium pellets: the metal is exceptionally resistant to corrosion and high temperatures, and it absorbs very few of the neutrons produced by a nuclear fission reaction. The latter is essential for the chain reaction to run effectively inside the reactor's core and to sustain the production of energy.
By cladding uranium fuel, zirconium also helps protect the coolant, typically water flowing through the reactor core, from contamination. It is estimated that up to 90 per cent of zirconium produced in the world is used for nuclear power.
5. While most zirconium is used in the nuclear field, it is not limited to that
Being tremendously resistant to corrosion by many acids and alkalis, it is broadly employed in the chemical industry. Zirconium compounds are used in ceramics, abrasives, lamp filaments, jet engines and space shuttle parts. In the medical field, zirconium dioxide, also known as zirconia, is applied as a material for dental and surgical implants due to its biocompatibility and durability. Zirconia is also used as a gemstone - cubic zirconia - a synthesized material that can be a substitute for diamonds and other precious stones.
