Kaolin
Kaolin;
Since kaolin is an economical and very common raw material, it is widely used in many sectors besides the ceramics industry.
It is mainly used in ceramics, glass, frit, agriculture, rubber, plastic, food, paper, cement.
Kaolin is used in the ceramic industry to provide plastic and to benefit from its buoyant properties due to its fine grain.
For the ceramics industry, kaolins that are white in color, have casting properties and have high buoyancy are preferred.
Although kaolin has many forms of formation, it generally has a rocky structure. Its main characteristics are silica and alumina.
As the aluminum oxide ratio increases, the quality of kaolin increases, but in some sectors the opposite may be desired. Generally, the SiO2 ratio varies between 60-85% and the Al2O3 ratio varies between 15-35%.
Koalin is also burned at 800-1000 C to produce calcined kaolin. The Al2O3 ratio in calcined kaolin can increase to 50%. Especially in porcelain production, calcined kaolin can contribute to the increase in quality.
Again, in the ceramics industry, organics and impurities in raw kaolin are filtered out by precipitation and filtering methods to obtain better quality filtered kaolin.
By preferring filtered kaolin in ceramic Angob and glazes, glaze errors called holes and pinholes that may occur on the surface are prevented.