Pressure filtration technique for complete characterization of consolidating suspensions

The behavior of suspensions in settling and compression is fully defined by two parameters: the compressive yield stress function P-y(phi) and the hindered settling function r(phi). The compressive yield stress quantifies the strength of the suspension network in compression and determines the maximum concentration achievable for any given applied force. The hindered settling function quantifies the hydrodynamic drag forces experienced by consolidating particles in the suspension and determines the settling velocity and the time scale for the consolidation process. Here, both P-y(phi) and r(phi) are determined using a constant pressure filtration device. The technique is explained and results for ZrO2 suspensions are presented. Using this single experiment, any consolidation process such as filtration or continuous thickening can be designed or optimized on the basis of the measured properties of the process suspension.