Ammonium paratungstate（APT）is white crystalline salt, with the chemical formula (NH₄)₁₀(H₂W₁₂O₄₂)•4H₂O. It is the most important raw material for most of tungsten products. Intermediates such as tungsten trioxide, tungsten blue oxide, tungstic acid, can be obtained from APT, either by thermal decomposition or chemical conversion.

Tungsten alloy shielding plate is used to absorb X-rays scattered and transmitted by a CT scanner. You know, some X-rays could enter the surrounding environment through scattering and transmission during CT scanning, which may affect the health of operators, patients and their accompanying family members.

Ammonium paratungstate (APT) is regarded as an important precursor of many tungstic product. A major product from thermal decomposition of APT is tungsten trioxide (Wo₃), which is the active phase in tungsten-based catalysts. Furthermore, it is applied in varied field of gas sensors, catalysis, electrochemistry, and photocatalysis owing to its excellent gasochromic, acidity, electrochromic and photochromic properties. Meanwhile, tungsten trioxide, with a band gap between 2.4 and 2.8 eV, is a visible light response catalyst with stability under acidic conditions, which makes it a suitable choice for the photocatalytic oxidation of organic pollutants under solar irradiation.

Tungsten alloy radiation shield is an essential protection part on CT machine. The radiation shield made of high density tungsten-based alloys may be a tungsten alloy plate, a tungsten alloy tube or a tungsten alloy shielding device. You know, CT examination is X-ray examination, which produces ionizing radiation. In order to minimize the radiation to the patient, a tungsten alloy shield with excellent X-ray absorption shielding effect is necessary.