Rheological and Dispersing Properties of Calcite-Goethite Mixed Aqueous Suspension

Abstract

Based on flow and sedimentation measurements, rheological and dispersing properties of calcite-goethite mixed suspensions were evaluated and their mutual correlation was discussed. By applying Casson's equation to the results of flow measurements, two parameters, as and αβ, were calculated, whereas from sedimentation experiments the median diameter and the sedimentation volume were obtained and taken as the criteria of dispersity. These four parameters varied themselves parallel to each other with varying mixing composition of two solid components, total solid content being kept constant, and they showed maxima at the volume fraction of goethite approximately equal to 0.8. The parameter αβ was found to serve as a practical and yet well defined measure of interparticle forces in liquid media, even for a mixed suspension where heteroflocculation predominantly takes place.