Rheological Evaluation and Aggregation of Suspensions of Large Glass Spheres in Aqueous Media

Abstract

The rheology of suspensions is of critical importance in mineral processing operations where solid materials are often transported as suspensions in pipelines. Consequently a knowledge of suspension rheology is essential for efficient plant operations. The flow properties of the suspension determine the energy requirements for pumping, the minimum rate of flow which must be maintained to prevent sedimentation, and the dynamics of start-up processes involved after a period of no flow during which the solids may have settled (Condolis and Couratin, 1972). The rheology of dilute suspensions is relatively well understood but dilute suspensions are of limited technological interest. Concentrated suspensions, on the other hand, are of great importance, but are much less well understood, principally because they behave as non-Newtonian fluids and their rheology is influenced by many variables. This study investigates the rheology of concentrated suspensions of large (d50 = 70μ) glass spheres, looking at the dependence of plastic viscosity on volume fraction and temperature. Modifying the spheres was also investigated to determine the relative importance of factors which contribute to the rheology of coarse suspensions.KeywordsConcentrate SuspensionGlass SpherePlastic ViscosityBarium NitrateMaximum Packing FractionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.