As per Harman and Fraulini, the ionic exchange capacity, permeability, heat of wetting and drying shrinkage are not directly related to grain size. However permeability depend on both the apparent and the true surface, particularly on the pore space, which in turn depends on the packing density.
If the individual clay minerals are converted to the K forms by electro dialysis macromolecular compounds can be attached to them. By this means the unoccupied lattice position can be blocked in such a way that they are no longer capable of taking up water. Clays treated in this manner have a low shrinkage and give rise to a very porous biscuit, which is an interested material for insulation medium.
To be contd……
