Kaolin
Kaolinite is a hydrated aluminosilicate mineral whose chemical formula is Al2Si2O5(OH)4and is a clay mineral composed of plate-like sheets that commonly appear as "stacked books". These platelets are on the order of 1 to 50 microns (0.001 to 0.050 mm) long and seven angstroms (molecular scale measurement) thick. The kaolinite occurs in the kaolin group of clay minerals, along with halloysite, which is also found on i-minerals Helmer-Bovill property. Aggregates of kaolinite, commonly termed kaolin, are typically soft and earthy with purer varieties being white. Kaolinite is commonly a product of chemical weathering, typically from the alteration of feldspar such as that in the Thatuna granodiorite in the Helmer-Bovill area. Kaolinite is hydrophilic, meaning that it can be relatively easily dispersed in water, a property desirable for many of its uses.Uses
Particle size and brightness are primary attributes that determine kaolin's value. The brightness is a measure of the amount of light kaolin reflects back. The higher the reflective characteristics of kaolin and the smaller the particle size, the greater the number of uses it has. Kaolin minerals long have been the basic raw materials used in the ceramic industry, especially in fine porcelains. They can be easily molded, have a fine texture, and are white when fired. Large quantities of kaolin are used in paper coating, filler, paint, plastics, fiberglass, catalysts, and other specialty applications. It can also be used as an ingredient in pesticides to replace toxic chemical pesticides in organic farming applications.
