EUKIM Ltd. is a manufacturing company highly active in industrial minerals and chemicals for the coating and plastic industries.
Calcined kaolin is used as a functional extender in paint. Calcined kaolin has proven to be an excellent extender for titanium dioxide (white) pigment in paint. Because Kaolin is chemically inert, has high covering power, gives desirable flow properties and reduces the amount of expensive pigments required.
Calcined kaolins are also useful in tuning the shrinkage and plasticity of slips (engobes) which are applied to wet or leather-hard ware. Engobes contain higher clay percentages than glazes and it is more important to control their drying shrinkage. Thus, like for glazes, they can be substituted for part of the raw kaolin to tune drying while maintaining fired properties.
Calcined kaolin is refractory and softens at about cone 35. It is thus useful in refractory castables and furniture, thermal insulation bodies, low expansion bodies, permeable ceramic compositions, and investment casting (see molochite).
If you are a potter you can make your own calcined kaolin by simply bisque firing any raw powdered kaolin (in a small enough bisque vessel and slow enough ramp that the heat penetrates well). Actually, roasting the powder at red heat is sufficient to destroy the plasticity. The material is a good example of how we can alter the mineralogy of a material to affect its working properties while maintaining the chemistry to retain fired properties.