Ceramic pigments are mineral pigments that are used in glazes, ceramic objects, sanitary ware, tiles and mosaics, granites, etc., and are resistant to high temperatures (1000 degrees Celsius and above). These pigments have chromophore ions that transfer color by dispersing and forming a heterogeneous mixture with the materials of the body of goods and ceramic devices or by glazing them.
Classification and characteristics of ceramic pigments:
Most ceramic pigments are metal salts or oxides of industrial chemical purity. Oxides, spinels, zirconates, aluminates and borates are examples of ceramic pigments. These pigments can be obtained both naturally and synthetically.
In general, ceramic pigments are placed in 3 classes: idiochromatic pigments such as uvite green (Ca3Cr2Si3O12) which has a color pigment, allochromatic compounds in which colorless minerals with metallic chromophores under Special reactions have been added to have coloring properties, such as zircon yellow ((Zr,Pr)SiO4) and composite pigments that are made of two phases and are divided into two groups: chemically absorbed pigments that color phase It is absorbed in the form of a film on the surface of the host structure, such as Baddelite yellow (V2O5-ZrO2) and included compounds in which the color phase particles are trapped in a stable and transparent phase, such as Cadmoselite red, in which cadmium sulfoselenide with Blocked zircon (ZrSiO4-CdSexS1-X). Cadmium sulfoselenide is the only ceramic pigment that can produce red and orange glazes.
Complex inorganic pigments or crystalline pigments are a group of ceramic pigments for glaze production, which are made by mixing oxides and silicates in the form of powders with suitable particle size and dispersion as a primary mixture, and then mixing them with a mixture. They combine mineral salts such as halides, borates, etc. To create a material with a suitable crystal structure, all materials are subjected to reaction in solution or reaction in solid state or even grinding. The final product can be idiochromic or allochromic. This group of pigments are chemically neutral and have high thermal resistance.