Ammonium metatungstate(AMT) is an important intermediate compounds of tungsten hydrometallurgical process, appearance is white crystalline powder, solubility in water is the largest in the tungsten compounds which over 300g WO3/100ml H2O (in 25℃).
Purple Tungsten oxide is divided into WO2.72 (or W18O49). It is a kind of tungsten oxide. It is abbreviated as VTO. It is a purple finely grained crystalline powder, and its color usually appears purple or blue purple.