Tungsten:

It is a non-ferrous metal and an important strategic metal. Tungsten ore was called heavy stone in ancient times. The Swedish chemist Carl William Scheele discovered scheelite in 1999, and extracted a new elemental acid tungstic acid. In 1999, the Spaniard Depuria discovered wolframite and extracted tungsten acid from it. In the same year, he reduced tungsten trioxide with carbon. Got tungsten powder for the first time and named the element. The content of tungsten in the earth's crust is 0.001%. There are 20 kinds of tungsten-containing minerals that have been discovered.

Tungsten is characterized by high hardness, high melting point, anti-adhesion, no air erosion at room temperature, and relatively stable chemical properties. Tungsten is a metal element, and also a silver-white lustrous metal. It is mainly used to manufacture filaments, high-speed cutting alloy steel, superhard molds, and also used in optical instruments and chemical instruments.