Composition of kaolin
Kaolin minerals are composed of kaolinite, kaolinite, pearlite, halloysite and other kaolinite minerals. The main mineral composition is kaolinite.
The crystal chemical formula of kaolinite is 2SiO2 Al2O3 2H2O, and its theoretical composition is 46.54% SiO2, 39.5% Al2O3, 13.96% H2O. Kaolin minerals belong to the 1:1 type layered silicate. The crystals are mainly composed of silicon oxy tetrahedron and eight - heoxo - hydroxide. The silicon oxygen tetrahedron is connected in the way of the common top angle to form a six square arrangement of grid layers. The oxygen level of the eight surface layer, the silicon dioxide tetrahedral layer, forms the unit type 1:1.