Kaolin is useless in food. In the old society and the three-year difficult period, the poor often lived by eating Guanyin soil. This kind of soil can satisfy hunger, but it cannot be digested and absorbed by human body. After eating, it is abdominal distension, difficult defecation, and a small amount is not fatal. Although you won't be hungry, people will die because of lack of nutrition. During the famine years, countless people were unable to defecate and suffocated because of eating Guanyin soil.

Kaolin (Guanyin soil) is the name of soil rich in kaolinite, which is mainly composed of alumina and silica. Kaolin is widely distributed in Gaoling area of Jingdezhen, Jiangxi Province, hence the name.

Composition of Kaolin: Kaolin minerals are composed of kaolinite, dickite, nacrite and halloysite, with kaolinite as the main mineral component.

The crystal chemical formula of kaolinite is 2SiO2●Al2O3●2H2O, and its theoretical chemical composition is 46.54% SiO2, 39.5% Al2O3, 13.96% H2O. Kaolin mineral belongs to 1: 1 layered silicate, and its crystals are mainly composed of silica tetrahedrons and octahedrons, in which the silica tetrahedrons are connected in two-dimensional directions in the form of vertex angles to form a hexagonal grid layer, and the common sharp oxygen of each silica tetrahedron faces one side; The unit layer of 1: 1 consists of spiral oxygen and oxygen-absorbing octahedral layer of common silicon-oxygen tetrahedron layer.

Its pure kaolin is white and delicate, soft and earthy, and has good physical and chemical properties such as plasticity and fire resistance. Its mineral composition is mainly composed of kaolinite, halloysite, hydromica, illite, montmorillonite, Yingshi, feldspar and other minerals. Kaolin has a wide range of uses, mainly used in papermaking, ceramics and refractories, followed by coatings, rubber fillers, enamel glazes and white cement raw materials, and a small amount used in plastics, paints, pigments, grinding wheels, pencils, daily cosmetics, soaps, pesticides, medicines, textiles, petroleum, chemicals, building materials, national defense and other industrial sectors.