The effect of normal load on the shear yield stress of suspensions

A.D. Stickland*, E. Höfgen, The University of Melbourne, Australia

Understanding the rheological behaviour of suspensions is crucial for the design and operation of processes involving mineral slurries and wastewater treatment sludges, and for the formulation and product performance of coatings and ceramics, for example. The solid particles in concentrated suspensions form continuous particulate networks that can withstand an applied force and behave as a soft elastic solid. Suspensions flow or collapse if the force exceeds the network strength at a given volume fraction f. The yield point in shear is often naïvely described by the shear yield stress, although this has been shown to vary with applied rate. In solid-liquid separation processes, a compressional load is applied to just the solid phase of the suspension. This is the applied pressure in filtration or the buoyant weight of the particles in sedimentation. If the load exceeds the compressive yield stress, the solid phase consolidates or densifies, that is, it forms a filter cake or a sediment. Consolidation continues until the network strength is equal to the applied load....

.... We have developed two new techniques and demonstrate that, upon confinement of the particles and application of a normal load...

Session: L2 - Particle, Slurry and Cake Characterization
Day: 22 October 2019
Time: 14:45 - 16:00 h

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