SHEAR YIELD STRESS OF PARTIALLY FLOCCULATED COLLOIDAL SUSPENSIONS

A general expression was derived for the shear yield stress of a flocc ulated suspension of particles that is able to describe the effect of particle-size distribution, solid loading, pH, and hence, electrokinet ics of the suspension. The model builds on an earlier model by incorpo rating the effect of the repulsive interaction between particles. Scal ing of the data to the maximum yield stress at a given volume fraction provides a means of removing particle-size- and volume-fraction-relat ed effects. The scaling process establishes that to a high level of pr ecision, concentrated dispersions act, in interparticle interaction te rms, as the sum of two-body interactions.