| Symbol: | Zr |
| Melting point: | 1,855'C |
| Electron configuration: | [Kr]5s24d2 |
| Atomic number: | 40 |
| Atomic mass: | 91.224±0.002u |
| Symbol: | Hf |
| Melting point: | 2,231'C |
| Electron configuration: | [Xe]4f145d26s2 |
| Atomic number: | 72 |
| Atomic mass: | 178.49±0.02u |
| Ore | Common Name | Formula |
|---|---|---|
| Silicate | Zircon | ZrSiO4 |
Zirconium is similar in its properties with titanium. Zircon is the important mineral containing zirconium. Zircon is a silicate mineral. Zircon is found in beach sands along with rare earth minerals. It is also found in some granitic rocks as semi transparent yellow crystals. These are also used as semiprecious gem stones. Zirconium is produced by reduction of zirconium oxide with magnesium. The oxide is produced by fusing zircon with potassium fluoride and treating with hydrochloric acid. Zirconium is mechanically weak at high temperature. Under high temperature it is rapidly corroded by water vapor and carbon dioxide. It is used in nuclear reactor as an alloy with tin, iron, nickel, and chromium. It is known as zircaloys. Zircon is superior to beryllium in corrosion resistance. It is also used in magnesium and titanium based alloys. Zirconium powder is compacted with lead to make lighter materials. It is used in photographic flash bulb. Zirconium is used as scavenger in steel making since it removes traces of both oxygen and sulphur. It is used in the form of ferro-zirconium and ferro-silico-zirconium. It refines the grain in steel and increases the strength of some alloy steel.
The major producers of zircon and zirconium metal are Australia, USA, South Africa, Russia, and India. Zirconium compounds are used as catalyst and a component in solid state devices. The zirconium oxide is used as refractory material. It is also used as abrasive materials and used in enamels. Zirconium is also used in copper alloys. It is used for electrical applications. Copper containing small amounts zirconium and chromium provide better strength after heat treatment. These alloys are used for their thermal and electrical conductivities. These are used in rocket nozzles and resistance welding electrodes.
Hafnium is a rare element. It is used as partial replacement for zircon. It is used in control rods in submarine nuclear reactors. It is also used in Hafnium-Columbium carbide. This alloy is used in making of cutting tools. Hafnium is found in association with zircon and zirconium bearing minerals