Compressive yield stress of flocculated suspensions: Determination via experiment

The compressive yield stress Py(ϕ) is an extremely useful parameter for the characterization of concentrated flocculated suspensions. It is a measure of the strength of inter-particle bonds in a networked suspension structure and is used in process design and control of mineral colloidal suspension dewatering. Previous work developed a method for determining this compressive yield stress via the equilibrium sediment height technique using a centrifuge. Here justification for a simple approximate technique to obtain Py(ϕ) is discussed. A new more accurate iterative algorithm is also described. By generating synthetic data, where the exact Py(ϕ) is known, the accuracy of the two techniques can be evaluated properly for the first time. The relative merits and failings of the techniques are discussed. An example is given to show how these techniques work on real experimental data.