In India most of the mines are open cast type and the clay excavated after removing the over burden is directly sent to different end users.
In some parts of India the excavated clay is blunged with water, passed through sieves and the clay is stored in separate settling tanks. The clear water is removed and the clay is allowed to dry into the settling tank itself. In some places the clay slurries are passed through filter presses and the cakes are dried in open sun heat.
The ball clay recovery rate is very high compared to china clay since it contains very low quantity of free silica and other impurities.
Ball clay is graded into different grades based on its plasticity like high plastic, medium plastic and low plastic. Different ceramic applications need different varieties and according to their requirements, the end users buy the clay from the manufacturers.
