Ammonium paratungstate (APT) is a white, crystalline powder that is commonly used in the production of tungsten metal and alloys. It is formed by the reaction of ammonium and tungstate ions in aqueous solution, which leads to the formation of a polyoxometalate compound.
APT is widely used in the tungsten industry as a raw material for the production of pure tungsten metal and various tungsten alloys, such as high-speed tool steels, superalloys, and electrical contacts. It is also used in the production of tungsten carbide powder, which is a key component in cutting tools, drilling bits, and wear-resistant coatings.