Kaolin, also known as porcelain clay powder; Kaolinite; Kaolin; Sericite; White clay; Porcelain clay; White soil; Ge Tu Fen et al. Molecular formula: H2 Al 2 O 8 Si 2 Molecular weight of H2 O: 258.16 pure white, generally gray or light yellow with impurities, dense or loose powder, with earthy taste. After absorbing water, it appears dark and has a special clay texture. The relative density is 2.54~2.60, and the melting point is about 1785 ℃. Has good smoothness. Do not burn. Insoluble in water, ethanol, dilute acids, and lye. After adding water and kneading, it has plasticity.

There are five major kaolin mining areas in China:

1) Jiepai Town, Hengyang County, Hunan Province is rich in mineral resources. The reserves of kaolin, feldspar, potassium feldspar, and quartz stone reach 200 million tons, and there are nearly 40 mining and mineral product processing enterprises. The Dapailing mining area (mainly composed of kaolin ore) has the highest single ore reserves in Asia, reaching 80 million tons. The annual mining volume of the entire town is over 500000 tons, supplying hundreds of ceramic factories nationwide.

2) The kaolin in the Maoming region belongs to the accumulation rock weathering residual subtype deposit in the Maoming Basin, with a sand content of more than 50% such as quartz. Therefore, it is called a sandy kaolin deposit. In terms of genesis, Maoming kaolin is formed through weathering residual - transfer self grinding—— There are three further stages of weathering, and the kaolin is thoroughly weathered, with single flake shaped crystals and fine particle size. The primary material is papermaking coating material.

3) Longyan kaolin is a weathered residual type kaolin deposit. Due to its iron content below 0.3%, titanium content below 0.02%, and a certain amount of low-temperature solvent element (Li2O), it is an ideal material for electric porcelain, high-end daily use, and art porcelain.

4) The Yangshan kaolin deposit in Gusu is a hydrothermal altered type of kaolin. The chemical composition of the pure Gusu Yangshan mud is very close to the theoretical composition of Kaolinite. The content of Al2O3 can reach about 39.0%, and the color is white and the particles are delicate. Mainly used as catalyst carriers and chemical materials.

5) Hepu kaolin: It belongs to the weathered residual type kaolin deposit. Primarily used for building ceramic materials.

6) Northern coal series kaolin: It is a type of accumulated kaolin, mainly distributed in coal areas in China, and can be used for construction, coatings, paint, and paper coatings - coal series kaolin.

The output value of the six major production areas mentioned above accounts for over 80% of China's total output value, and they also have primary representativeness in terms of resource types.