Kaolin Clay belongs to silicate mineral. Its main component is silicon dioxide and aluminum dioxide. We have two types of kaolin clay which are washed kaolin clay and calcined kaolin clay. Washed kaolin clay is processed by simple washing and crushing from the raw kaolin ore. Calcined kaolin is derived from raw kaolin ore after high temperature calcination and grinding. The basic particle sizes of kaolin clay are from 325 mesh to 6000 mesh. The main application of kaolin clay are paper industry, ceramics, plastics, rubber filler and paint&coatings additives. Nowadays industries are still widening the usage of kaolin clay.
The color of kaolin filler is white, or close to white, with a maximum whiteness of over 95%. The color of kaolin slightly changes with different metal or organic matter contents, and it appears rose red and brown yellow when containing Fe2O3; When containing Fe2+, it appears light blue and light green; Contains Mno2 and appears light brown; When containing organic matter, it appears light yellow, blue, gray, black, etc. Kaolin is mostly a dense cryptocrystalline or earthy aggregate. Hardness 2.0~3.5, specific gravity 2.60~2.63, melting point 1780 ℃, good insulation, low plasticity.
Kaolin fillers are mainly used to make daily ceramics, industrial ceramics, building and sanitary ceramics, and refractory materials. They are also used as fillers or white pigments in papermaking, construction, coatings, rubber, plastics, textiles, and other industries. With the development of industry, agriculture, and science and technology, kaolin has become a necessity in industries such as medicine and national defense.