Cadmium tungstate (CWO) is a scintillation crystal. There is currently no mass production company in my country.

Cadmium tungstate, with the chemical formula CdWO4, or CWO for short, is an inorganic compound that appears as colorless or white or yellow crystals. It is irritating, basically insoluble in water, insoluble in dilute acids, and soluble in ammonium hydroxide solution, Cyanide base solution. Cadmium tungstate is a typical self-activating material and an important scintillation crystal with excellent photoluminescence properties. It has the advantages of strong radiation resistance, large ray absorption coefficient, high luminous efficiency, and low afterglow. .

Cadmium tungstate has a large X-ray absorption coefficient and plays an important role in the field of X-ray imaging equipment. It can make X-ray fluorescent screens, scintillation detectors, etc.; it is irreplaceable in the field of scintillator and can make scintillation counters and detect gamma rays. etc.; it can emit fluorescence under ultraviolet irradiation and can be used as color-developing materials, color-changing materials, and in production fields such as fluorescent coatings; it can be used as an organic reaction catalyst and is a good carrier for constructing efficient photocatalytic composite materials. An important use of cadmium tungstate is to manufacture medical CT and industrial CT. It is widely used in disease diagnosis and treatment, industrial non-destructive testing, port container detection, laboratories and other fields.

The preparation methods of cadmium tungstate mainly include liquid phase synthesis method, pull method, crucible descent method, etc. The liquid phase synthesis method can be used to prepare cadmium tungstate polycrystalline materials, but the quality cannot meet the requirements of scintillator; the Czochralski method can be used to grow cadmium tungstate single crystals with high transparency and large size, which can be used as scintillator materials, but this method Growth is difficult, and crystals are prone to problems such as inclusions, cracks, and coloration. The current mainstream preparation method for cadmium tungstate single crystals is the crucible descent method, which can grow single crystals with high purity and large size to meet the needs of scintillator manufacturing.

Divided according to purity, cadmium tungstate includes 99% (2N), 99.9 (3N), 99.99% (4N), 99.999% (5N) and other grade products. The higher the purity, the stricter the technical process requirements of the manufacturer. According to Cadmium Tungstate (CWO) Industry Depth from 2022 to 2026 released by the Industrial Research Center Market Research and Investment Strategy Recommendations Report shows that currently, globally, the main manufacturers of cadmium tungstate monocrystals include American Elements, Dynasil of the United States, and Saint-Gobain of France. , British NANOSHEL, Japanese Hamamatsu, etc. Due to high technical barriers, there are currently no mass-producers of cadmium tungstate single crystals in my country, and market demand relies on imports.

Industry analysts said that scintillator is indispensable in X-ray imaging equipment, and its function is to absorb X-rays and convert them into fluorescence signals. Against the background of the continuous improvement of my country’s independent research and development and production capabilities of medical CT and industrial CT, the independent supply capability of scintillator needs to be enhanced urgently. Yirui Technology is my country’s representative X-ray imaging equipment manufacturer. In order to achieve independent control of core raw materials, it plans to raise investment to build a scintillator material industrialization project, including cadmium tungstate crystals. In the future, my country’s cadmium tungstate supply capacity will gradually increase, and import substitution will gradually be achieved.