University Colleges of Science & Technology, Calcutta
The exchange isotherms of Ni-, Co-, and Cr-clays were obtained against Na, K, NH4, H, Mg and Al ions. In general, the following order of release is shown: Co=Ni > Cr. The sequence of adsorption is the reverse of it. These sequences are more or less in agreement with the lyotrope series. The exchange behaviour of H ion is anomalous, as has often been observed in the case of similar colloidal reactions. The exchange behaviours of NH4 and K, and Co and Ni ions, each pair having nearly identical radii, are nearly the same.
