Chemical composition of cadmium red pigment

There are many types of pigments used in enamel and glass, including cadmium red pigment, cobalt blue pigment, chromium green pigment, cadmium yellow pigment, coffee pigment, melanin, etc. The chemical composition and manufacturing process of cadmium red pigment are mainly discussed here.

cadmium red pigment

Cadmium red is also known as red pigment, pigment red 108, big red pigment, including cadmium orange, dark cadmium red, medium cadmium red, light cadmium red, purple cadmium red and other varieties. They are all cadmium pigments, and their properties are similar to the production process. The chemical composition can be represented by the general formula nCdS•CdSe or Cd (SxSe1-x).
The color of cadmium red is very saturated and vivid, and the color spectrum ranges from yellow, orange to red to purple sauce. The higher the CdSe content in cadmium red, the stronger the red light and the darker the color. The more cadmium ions in cadmium sulfide are replaced by selenium ions, the more the color shifts to purplish red.
The shape of cadmium red particles is basically spherical, and its crystal structure is mainly hexagonal crystal type, but also cubic crystal type. The heat resistance of cadmium red is about 600°C, and it decomposes violently above 800°C. Cadmium red has excellent weather resistance and corrosion resistance, strong hiding power, insoluble in water, organic solvents, oils and alkaline solvents, and slightly soluble It is in weak acid, dissolves in strong acid and emits toxic gases H2Se and H2S.