How tungsten is made

Tungsten melts at 3,422 °C, hotter than any other metal, so it is never melted and is pressed from powder.

stations: 6
things upstream: 4
raw sources: 3
steps from the ground: 2

The short version

Tungsten ore is crushed and concentrated, then dissolved and precipitated with ammonia to make a tungsten salt. The dried powder is heated into tungsten oxide and reduced with hydrogen to a gray metal powder. Since the metal's melting point is too high for casting, the powder is pressed and sintered into solid bars.

Crush and concentrate

The ores, wolframite and scheelite, are rarely more than 1.5 percent tungsten oxide. They are crushed, then scheelite is floated and wolframite is separated by gravity and magnets.

Goes in
Tungsten ore
Dissolve it as tungstate

The concentrate is dissolved into a water solution of tungstate. Ammonia is added, and a tungsten salt precipitates out and is filtered.
Dry it to an oxide

The precipitate is dried at 600 °C, and the result is a fairly pure tungsten oxide powder.

600 °C
Reduce it with hydrogen

The oxide is heated in a stream of hydrogen, which takes away the oxygen as water and leaves tungsten powder. Carbon is not used, because heating with coal makes tungsten carbide instead.

Goes in
Hydrogen
Press and sinter the powder

Tungsten melts at 3,422 °C, the highest of any metal. So the powder is pressed into bars and sintered, meaning heated until the grains fuse without liquefying. The product is somewhat porous.
Work it into wire and rod

Once purified, tungsten can be forged, drawn, rolled or extruded, though raw tungsten is brittle and hard to work. Drawn wire becomes light bulb filaments.

End of the lineTungsten Next it goes into incandescent light bulb, tungsten carbide, drill bit.

Worth repeating

Between 60 and 70 percent of the world's tungsten goes into cemented carbide, which is used for cutting tools, drills and wear parts.
The name means 'heavy stone' in Swedish, and wolfram, the name used in German, comes from the mineral wolframite.