AbstractIn the extraction of bitumen from Canada's oil sands reserves, bitumen droplet coalescence is an important factor in determining the efficacy of the separation process. In a simplified analysis of bitumen droplet interactions, the relative contributions of classical DLVO and non‐DLVO forces occurring between a bitumen droplet and surface‐treated planar collector were evaluated using the impinging jet cell technique. Initial experiments were conducted using a system consisting of silane‐treated silica particles and a hydrophobic collector. This system is known to exhibit attractive non‐DLVO interactions as was clearly demonstrated by the present study. The attachment of bitumen droplets onto two different hydrophobic collectors was then examined. Results of these experiments indicate that bitumen droplet interactions involve an additional repulsive force that may be attributable to the heterogeneous nature of the droplet surface.