|Chemical Element||Tungsten (Wolfram)||Melting Point °C||3407|
|Chemical Symbol||W||Boiling Point °C||5700|
|Atomic Number||74||Density g/cm3||19.3|
|Atomic Weight||183.84||Oxide||WO2, W2O5, and WO3|
Tungsten is a lustrous and silvery-white metal that is a member of Group 6 of the Periodic Table, a group it shares with the lighter metals chromium and molybdenum. It is the 58th most abundant element within the Earth’s crust. Tungsten is the metal with the highest melting point, and the highest tensile strength at temperatures above 1300°C when it is red hot. The bulk metal resists attack by oxygen, acids and alkalis. Tungsten is a very dense element and also cheap, therefore is used in applications where a lot of weight is needed in a small space.
Evidence of use of tungsten dates back to the 1600’s: in China, porcelain manufacturers used tungsten as a peach-coloured pigment without actually knowing what it was. The discovery of tungsten is credited to two Spanish brothers,Juan Jose Elhuyar and Fausto Elhuyar, who came from northern Spain. In 1783, the brothers analysed two minerals, tungsten and wolframite, and by doing this, confirmed that they both yielded the same acidic metal oxide, some of which they were able to reduce to the metal itself.
The most commonly traded forms of tungsten include ammoniumpara tungstate (APT) and tungsten oxides, ferro tungsten and tungsten metal powder or bar. Interestingly, in its purest form, tungsten is relatively pliant and can easily be cut with a hacksaw, but usually it contains small concentrations of carbon and oxygen, which give tungsten metal its significant hardness.
In the past tungsten’s high strength and resistance to high temperatures has made it an important raw material in the weapons industry and during World War 2, Portugal was put under immense pressure by both the Allies and the Axis powers, as it was the main European source of thismaterial.
Today tungsten makes a significant contribution to the achievement of high productivity levels in mining, construction, metal and wood working and wear protection, through its use in cemented carbide and high speed steel tools.
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- Gray, Theodore. The Elements, A Visual Exploration of Every Known Atom in the Universe, Black Dog & Leventhal Publishers, Inc, NY, 2009
- Stwertka, Albert. A Guide to the Elements, 3rd Edition, Oxford University Press, 2012