HYDROLYSIS OF ALKALI AND ALKALINE EARTH FORMS OF MONTMORILLONITE IN DILUTE SOLUTIONS

Abstract

The hydrolysis in pure water of montmorillonite in various homoionic forms is discussed. During normal preparation procedures nominally homoionic alkali metal and alkaline earth metal montmorillonite hydrolyzes to an extent governed by the nature of the counterions. The hydrolysis during preparation may remove as much as 16% of the initial counterions. The remaining capacity is taken up by exchangeable M and Al. Long-term water leaching experiments indicate that eventually not only hydrolysis but also decomposition reactions take place, with the result that the ion exchange capacity becomes reduced.