This paper presents results of studies on structural parameters and settling rates of aggregates formed during bench- and pilot-scale paraffinic froth treatment (PFT) at about 80 degrees C, during extraction of bitumen from the oil sands. The structures of individual aggregates were investigated using light microscopy, and their composition was estimated on the basis of image analysis. In addition, the settling velocities and dimensions of the aggregates were measured. It was found that the energy input during mixing of solvent and froth (proportional to mixing speed and duration) during PFT influenced the composition and settling velocity of the aggregates. Greater energy input resulted in higher concentrations of mineral particles (DS) in the aggregates. In bench-scale experiments, the concentration of minerals in the aggregates increased from 10 wt % to about 65 wt % with increasing energy input. The corresponding settling velocities of the aggregates increased from about 50 mm/min to above 700 mm/min. In pilot-scale tests, the average mineral content of aggregate samples was around 70 wt %, while the settling velocity ranged from 600 to 900 mm/min. It was found that the aggregates formed at higher temperature had relatively dense, nonporous structures consisting mainly of minerals and precipitated asphaltenes, and they settled rapidly. The average density of aggregates formed during pilot-scale tests, estimated on the basis of settling tests, was reaching 2000 kg/m(3).