BITUMEN-SAND INTERACTION IN OIL SAND PROCESSING

Bitumen-sand interaction was studied as a function of pH, particle size. temperature and solvent addition to bitumen. Sand particles can be easily detached from the bitumen surface at pH > 6, At pH < 6. strong attachment between bitumen and sand is observed. The bitumen-sand interaction is also particle-size dependent: the finer the particles, the stronger the attachment. The detachment of coarse particles from bitumen can be achieved by increasing the alkalinity of the solution, but not for fine particles. indicating that the particle size is one of the critical factors affecting liberation of bitumen from sand. Increasing temperature has two effects: it is not only reduces the viscosity to facilitate bitumen liberation, but also increases the electrostatic repulsion between sand and bitumen. This is confirmed by the DLVO theory and is in agreement with the batch extraction results on real oil sands.