Kaolin clay is widely used industrial clay that has a variety of commercial applications such as like architectural and industrial coatings, paint, inks, construction, wire and cable, rubbers, plastics, packaging and papers. Also known as China Clay, Kaolin can be easily distinguished from other industrial clays owing to its fine particle size and pure white color. It is also regarded as an ideal pigment because of its ability to disperse in water. BASF Corporation, U.S.A is the principal Kaolin clay supplier globally as the world’s finest quality Kaolin clay deposits can be found in the southeast of the United States.
Often, people are found to be curious to understand the difference between Kaolin clay and Kaolinite clay. This is because the white colored, fine particles clay frequently finds a mention across several resources sometimes as Kaolin clay or sometimes as Kaolinite clay. This causes confusion amongst readers. The following section would help one understand how these two terms are different from each other or are related to each other.
Kaolin clay is derived from the mineral Kaolinite which comes from the Earth’s crust. It is a hydrous aluminum silicate formed by the decomposition of minerals such as feldspar and is represented by the chemical formula Al2Si2O5(OH)4, which is also alternatively represented by the formula AI2O3•2SiO2•2H2O. The mineral Kaolinite, also referred to as Kaolinite clay, is a layered silicate mineral and is soft, earthy, and usually white in color, produced by the chemical weathering of aluminum silicate minerals. Rocks that are rich in Kaolinite are also known as Kaolin or China Clay. This means the terms Kaolin clay and Kaolinite clay can be used interchangeably and this is what happens even in practice. Let us now understand the different forms and uses of Kaolin or Kaolinite clay.
Kaolinite clay undergoes a series of structural transformations upon thermal treatment in air at atmospheric pressure. For instance, under exposure to dry air and between 100 °C and about 550 °C, the liquid water gets removed from the Kaolinite and becomes dry. At subsequent higher temperatures, further transformation continues resulting in substantial increases in both structural strength and heat resistance.
BASF Corporation, which is one of the globally renowned Kaolinite clay suppliers, offers the product in several forms or categories to suit different applications. These categories include –
- Calcined – Calcined Kaolin clay is obtained by calcination of water-washed Kaolin at a very high temperature (usually above 1050 degree centigrade) causing loss of moisture.
- Hydrous Spray Dried – This is a water-washed variant of the clay that has been treated using an intensive process to a fine powder.
- Hydrous Pulverized – This is also another water-washed variant of the clay that is treated to produce a dry coarse powder.
- Surface Treated – Surface modified clays are produced by surface coating calcined clay with a chemical. This treatment may vary based on the application or intended purpose or use.
Leading Kaolin clay or Kaolinite clay suppliers across the world are sourcing the clay products from BASF Corporation as well as other globally renowned companies for a range of industrial and commercial applications.