structural:reformatting
Drying

Below 100 °C, exposure to low humidity air will result in the slow evaporation of any liquid water in the kaolin. At low moisture content the mass can be described leather dry, and at near 0% moisture it is referred to as bone dry.

Above 100 °C any remaining free water is lost. Above around 400 °C hydroxyl ions (OH) are lost from the kaolinite crystal structure in the form of water: the material cannot now be plasticised by absorbing water. This is irreversible, as are subsequent transformations; this is referred to as calcination.