Experimental study of the rheology of water-kaolinite suspensions

Abstract

How the added electrolyte condition and size of primary sediment particles, as well as the particle concentration, affect the rheological behaviours of water-sediment suspension remains to be of interest in the sediment field. In this work, rheological experiments of water- kaolinite suspensions with different electrolyte conditions, two particle sizes and 39 solid concentrations were performed. The Bingham fluid model has been adopted to fit the experimental data, and the viscosity and Bingham shear stress values were calculated for each suspension. It has been found that an increase in electrolyte concentration and/or valence leads to a larger viscosity value of the suspension, whereas an increase in electrolyte valence yields a smaller Bingham shear stress value. A simple interpretation based on DLVO theory was presented in this study. It has also been observed that a fine-grained kaolinite suspension corresponds to larger suspension viscosity and Bingham shear stress values. Additionally, some experimental information on the viscosity-solid concentration and Bingham shear stress-solid concentration relationships were also presented in this study. For the viscosity-solid concentration data, the Krieger and Dougherty formula provided the best fit, and a simple exponential relation showed a good fit for the measured shear stress-solid concentration data.