Ammonium paratungstate is a kind of tungstate. Commonly known as APT, the English name is ammonium paratungstate. The molecular formula is 5(NH4)2wo 35 H2O. Clean white crystal, slightly soluble in water, stable in air at room temperature, and begins to decompose into WO3 at 25℃. The main producing provinces are Jiangxi, Hunan and Fujian. The main export areas are Europe, Japan and the United States.