Surface chemistry, rheology, consolidation and shear behaviours of kaolin: alumuna/silica sheet contribution and cation and flocculant effects

[Truncated] Kaolinite clay is an invaluable mineral used in numerous applications. It is also a waste material found in mineral tailings. Due to its heterogeneous particle surface charges and poor consolidation behaviours, extensive research has been carried out to understand the properties of these particles that could resultantly allow improvements in their consolidation behaviours within mineral tailings.

Despite the extensive research carried out on kaolin, paucity in literature exists concerning the possibilities of kaolin particles, in as-received conditions, carrying different elemental compositions that can substantially alter the kaolin particle surface charge, rheology and consolidation behaviours even prior to any manipulation to the particles or slurries. In Chapter 4, it was aimed to display if and how these kaolin particle behaviours alter due to concentrations of elements found naturally and in sufficiently high concentrations on the particle. Results showed that the commercially produced Unimin kaolin particle carries sufficiently high Ca²⁺ concentrations that caused its zeta potential-pH, yield stress-pH and sedimentation behaviours to vary from that usually displayed by most, pristine kaolin slurries. This result exposes the potential surface charge, rheological and consolidation variability that can exist between commercially produced kaolin powders to suggest that particle characterisation via elemental analysis is required prior to experimental research on the kaolin particles in response to changing conditions.