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:

Centrifuging The centrifuge separates the fine kaolin particles from coarse particles.
Fine particles, still in the form of slurry, move on for further processing to enhance brightness.

With both the fine and coarse kaolin particle fractions, brightness is enhanced through one or move processes including bleaching, magnetic separation, flocculation, ozonation, flotation, and oxidation, which will remove iron, titanium, organic, and other undesirable materials.

• Delamination

  For customers who want a delaminated clay product suited for lightweight coating applications, coarse particles are used. Delamination occurs as the coarse particles of kaolin ­ which when magnified appear as "booklets" ­ are broken into thin platelets.

After delamination, the brightness of the coarse particles may be enhanced through one or more of the same processes used in the fine particle fraction.