Swelling of Calcium Montmorillonite

WARKENTIN et al. 1 , following up earlier work of Schofield 2 , Bolt and Miller 3 , and others, showed that swelling pressures developed by suspensions of sodium montmorillonite on an ultra filter could be predicted satisfactorily from a diffuse ion layer model based on classical Gouy–Chapman theory. Warkentin et al. also reported results of preliminary experiments with calcium montmorillonite for which the same model appeared to be inappropriate. A significant result was the decrease in magnitude of reswelling observed as the peak pressure applied to the sample increased. They concluded that forces not taken into account in the calculation must be present. Recently, Aylmore and Quirk 4 , Greacen 5 and others have published discussions of these results which may now require reconsideration in view of further studies of calcium montmorillonite swelling.