Characterization of montmorillonite saturated with various cations

Emanation thermal analysis (ETA) supplemented by thermogravimetry (TG and DTG) and evolved gas analysis (water) were used for the characterization of the thermal behavior of montmorillonite samples saturated with lithium, sodium, magnesium and aluminum cations. The ETA revealed microstructure changes that occur during the gradual heating of the clay. These changes are associated with the dehydration, dehydroxylation and formation of an amorphous meta-montmorillonite phase, and its subsequent annealing and recrystallization. On the basis of the ETA results it was demonstrated that exchangeable metallic cations have a great effect on the thermal behavior of montmorillonite.