The Effect of Lithium on the Cation Exchange Behaviour of Crystalline and Amorphous Clays

The amount of cations displaced by LiCl—LiOAc from standard clay minerals and soil clays was dependent on the concentration and pH of the replacing solution. Lithium was more effective in replacing monovalent ions than ammonium. Appreciable quantities of Li were adsorbed by replacement on the broken bonds of the clay surfaces, especially in the amorphous clays. Certain montmorillonite clays fixed some of the sorbed Li. In general, the cation exchange behaviour was highly dependent on the structure of the clay mineral and the nature of its surface. The sum of displaced cations can be taken as representing the exchange capacity of the clay at the experimental conditions, while the amount of retained Li provides supplemental information on the nature of the bonds.