( Water washed process )

The processing of kaolin varies greatly from company to company, each kaolin producer uses different equipment and methods. Also, companies that use identical methods may use them at different points during processing.

A good example of the extensive processing of kaolin is found in those products intended for the paper industry. The greatest demand for kaolin-based pigments comes from the paper industry, which uses them to coat and fill papers and boards. There are many ways to produce these pigments. One of the methods used is called the "water washed process."

Generally, in the processing of water washed clays, water is used as a transport and process medium involving the following:

•         Blunging

•         De-gritting

•         Centrifuging

•         Brightness Enhancement: delamination, filtering & drying, additional processing, packaging & shipping

Blunging

The kaolin is mixed with water and chemical dispersants to create milk-shake-like slurry. Slurry is simply the water and dispersed clay mixture, which puts the clay particles in suspension.

De-gritting

The slurried kaolin is usually transported through pipelines to degritting facilities, where sand, mica and other impurities are extracted with the help of gravity.