Abstract
The softening effect of more than 200 bentonite samples has been studied. The softening index, cation exchange capacity (CEC), adsorption, mineral composition and amount of soluble silica were examined.
It was found that, in general, the softening effect was not a function of CEC but depended on the crystallinity of montmorillonite. Furthermore, the experimental results on various samples with classified fractions indicated that bentonite is characterized by the coexistence of cristobalite and montmorillonite and the crystallinity of montmorillonite is probably related to this coexistence.
