Kaolin is a kind of soft clay mineral deposit and non clay mineral deposit mainly composed of Kaolinite sub group mineral deposit. Kaolinite mineral deposits mainly consist of μ The fine lamellar or tubular Kaolinite group deposits in the form of Al4 [Si4O10] (OH) 8. Kaolin has many special properties that ordinary mineral deposits do not possess due to its hydrated aluminosilicate chemical composition, layered structure, and particulate nature. The widespread use of kaolin is inseparable from its excellent physical functions.

Pure kaolin has high whiteness, soft texture, and is easily suspended in water. It has outstanding plasticity and high adhesion, excellent electrical insulation function, outstanding acid resistance solution, low cation exchange capacity, and high fire resistance.

The drying function of kaolin refers to the function of kaolin mud during the drying process. Including dryness shortening, dryness intensity, and dryness sensitivity.

Kaolin dry shortening refers to the shortening of kaolin clay after dehydration and drying. Kaolin clay generally dehydrates and becomes dry at temperatures ranging from 40-60 ℃ to no more than 110 ℃. Due to the discharge of water, the particle distance is shortened, and the length and volume of the sample are shortened. Dry shortening is divided into line shortening and body shortening, expressed as the percentage change in length and volume of kaolin mud after drying to constant weight. The drying line of kaolin is generally shortened by 3-10%. The finer the particle size, the larger the specific surface area, the better the plasticity, and the greater the dry shortening. The shortening of the same type of kaolin varies depending on the amount of water added, with more having a greater shortening. In ceramic technology, if the dry shortening is too large, the body is prone to deformation or cracking.

The drying strength of kaolin refers to the flexural strength of the mud after being dried to constant weight.

The dryness sensitivity of kaolin refers to the degree to which deformation and cracking tendencies may occur when the green body is dry. High sensitivity, easy to deform and crack during dry processes. Generally, kaolin with high dry sensitivity (dry sensitivity coefficient K>2) is prone to defects; The lower (dry sensitivity coefficient K<1) is safer in dry environments.