Tungsten Metal Powder (WMP)
Tungsten, also known as wolfram, has the chemical symbol W and is element 74 of the periodic table. It has the highest melting point of all elements except Carbon, the lowest expansion coefficient of all metals and also excellent high temperature mechanical properties. In addition, with a density of 19.25 g/cm3, Tungsten is among the heaviest of metals.
To produce Tungsten metal powder, yellow or blue Tungsten oxide is reduced by hydrogen. The reduction is carried out in pusher furnaces, in which the powder passes through the furnace in boats, or in a rotary furnace, at 700 – 1000°C.
Tungsten is the key component of the following applications:
- Mill products such as lighting filaments, electrical and electronic contacts, wires, and rods
- Cemented Carbide and high speed steel tools
- Chemical uses, such as catalysts and sprays
- Television sets
- Magnetrons for microwave ovens
Tungsten Carbide Powder (WC)
Tungsten Carbide is quantitatively the most important Tungsten compound. Because of its hardness – close to that of a diamond – it is the main constituent in cemented Carbide.
Most of the Tungsten metal powder is converted to Tungsten Carbide (WC) by reaction with pure Carbon powder, e.g. Carbon black, at 900 - 2200°C in pusher or batch furnaces, a process called carburization.
Tungsten Trioxide (WO3)
Tungsten trioxide is well known as an intermediary compound in the process of converting tungstates to pure Tungsten. The compound is reduced to pure metal by using Carbon or hydrogen gas. Chemical applications for Tungsten trioxide includes catalysts, inorganic pigments (used in the ceramics industry), and high-temperature pigments.
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