The influence of solid type and content on the rheological behaviour of coagulated slurries and their bearing on the consolidation by pressure filtration

Abstract

The present work is part of a model study aimed at upgrading the technique of creating porosity within a ceramic body via the incorporation of organic particles, used in traditional ceramics, exploring at the same time the colloidal processing from coagulated slurries. The method described by Lange et al., based on the manipulation of short-range repulsive (lubricating) hydration force and long-range attractive van der Waals force, was used to pack to a high density a bimodal mixture of submicron ceramic particles (matrix) and larger organic particles (inclusions) during consolidation by pressure filtration of dispersed suspensions coagulated by added electrolyte. The results reported show how the rheological behaviour of dispersed ceramic slurries changes through coagulation by added electrolyte, the role played by added organic particles and how they affect the coagulation state, bearing on the conceptual relation between interparticle potential and the observed rheological behaviour. (C) 1996 Elsevier Science Limited.