Calcination is a thermal process by which a substance, such as minerals, clays or ceramic compounds, is heated at controlled temperatures to remove impurities such as gases, moisture and organic matter. This heating generally occurs at temperatures lower than those of complete firing, but high enough to cause chemical and physical changes in the material. Calcination transforms the chemical structure of the substance, making it more stable, less plastic and suitable for use.
In ceramics, this process is used to prepare minerals and oxides prior to their incorporation into glazes and clay bodys. The main objective is to avoid decomposition or the release of gases during the final firing, which could cause defects such as bubbles or cracking in the finished pieces. For example, calcined calcite is used in the formulation of ceramic glazes, ensuring a homogeneous and stable mixture during vitrification.
In addition, calcination improves the functional properties of certain ceramic materials by eliminating volatiles and reducing the risk of irregular shrinkage during firing. It is also a crucial step in the production of technical and refractory ceramics, where high thermal resistance and dimensional stability are required.
Interesting Fact
Calcination is also used in the production of cement and other construction materials to increase the strength and stability of the composites.
Helpful Tip
Be sure to handle calcined materials properly, as some of them, such as quicklime, can be irritating if not handled with proper precautions.
