| In oil sands mining operations, water-based mixtures containing coarse sand grains and fine mineral solids (including clays) are ubiquitous. The clay fraction can have a detrimental effect on the separation of bitumen from the oil sand matrix, on the hydrotransport pipelines, and on water recycle. As such, the particle size and concentration of the colloidal clay particles and the rheology of aqueous suspension of these particles must be monitored.;The Particle Size Distribution (PSD), along with pH and ion concentration in the continuous phase, govern particle-particle and particle-continuous phase interactions. These interactions in turn dictate the overall behavior of mixtures containing clays. Therefore, any factor that can bias or alter the clay PSD of the mineral solids must be investigated. For example these mixtures are typically exposed to sonication before particle size analyses are conducted. In this study, the effect of sonication on the kaolinite clay PSD - as an analog of the clays found in the oil sands - was examined. The size measurements were carried out using a Flow Particle Image Analyzer (Sysmex FPIA-3000). This study demonstrates that sonication results in a reduction of the number of large particles and also an increase in the proportion of the smallest particles. Results of experiments conducted on slurries having different pH, electrolyte concentrations and solids concentrations showed that these factors, along with sonication time and power, have a significant effect on the extent of the particle size reduction. |
