|University of Alberta
|Department of Chemical and Materials Engineering
|Bitumen Recovery; Oil Sands; Cationic Organic Dispersant
|Full text PDF:
The presence of fines deteriorates both bitumen recovery and froth quality due to slime coatings and entrainment of fines into the froth during bitumen extraction from oil sands. This thesis aims to understand the role of a commercially available cationic organic dispersant (COD) in bitumen flotation from mineable oil sands. COD dosage at 300 ppm was found to improve bitumen froth quality over 30% with a marginal reduction of 5% in bitumen recovery. Adsorption of the COD on both bitumen and kaolinite clay fines were confirmed by ξ–potential and QCM-D measurements. COD has a stronger affinity to fines than to bitumen based on the larger increment in ξ –potential value and the higher adsorption density of clays. COD adsorption makes the bitumen surface become less hydrophobic with a reduction in contact angle and an increase in the induction time between air bubble and bitumen. The improvement of bitumen froth quality was mainly attributed to the change in surface wettability of the oil sands solids due to COD adsorption, which led to a decrease in the hydrophobicity of oil sands solids.