Gh. Meeten, SHEAR AND COMPRESSIVE YIELD IN THE FILTRATION OF A BENTONITE SUSPENSION, Colloids and surfaces. A, Physicochemical and engineering aspects, 82(1), 1994, pp. 77-83
A suspension of compressive yield stress P0 will not be filtered unles
s the differential filtration pressure P exceeds P0. Measurements show
ing this pressure threshold are reported for a bentonite clay suspensi
on. The cumulative filtrate volume for the suspension is found to vary
as P0.215-P-0(0.215), from which P0 is obtained. The shear yield stre
ss tau0 of the suspension is obtained from analyses of conventional sh
ear rheological data. A friction angle alpha for bentonite, given by a
rcsin(tau0/P0), is closely similar in magnitude to literature data for
similar clays in plastic deformation. Interpreted as an elastic prope
rty, tau0/P0 gives a Poisson ratio for the floc network which is numer
ically close to that of an elastic polymeric network.