Viscosity of concentrated clay suspensions: Effect of solids volume fraction, shear stress, and deflocculant content

Using the same clay, 28 concentrated clay suspensions were prepared with varied solids volume fractions and deflocculant contents. T he apparent viscosity of each suspension was determined at a range of shear stresses to produce flow curves. A functional relationship was derived based on the K rieger equation, describing the combined effect of solids volume fraction, deflocculant content, and shear stress on suspension viscosity when suspension behaviour is shear thinning. Intrinsic viscosity, a K rieger equation parameter, may be considered to be independent of deflocculant content. In contrast, intrinsic viscosity decreases significantly as shear stress rises, tending asymptotically to a constant value at high shear. Maximum solids volume fraction, the other K rieger equation parameter, rises as shear stress and suspension deflocculant content increase.