Canadian Journal of Chemical Engineering, Vol.87, No.1, 85-93, 2009
DISTRIBUTION OF CLAY MINERALS IN THE PROCESS STREAMS PRODUCED BY THE EXTRACTION OF BITUMEN FROM ATHABASCA OIL SANDS
This study investigates the affinity of clay minerals in oil sands for the water-continuous tailings and hydrocarbon-continuous froth streams produced from the extraction of bitumen from oil sands. Clay minerals in oil sands processing impact bitumen flotation in separation vessels, emulsion formation during froth treatment, and fine tailings behaviour. X-ray diffraction of oriented clay slides and random powder samples were used to quantify the clay minerals in the oil sands ore and process streams. Particle size distribution and clay activity balances were also conducted around the extraction process. The degree of partitioning during the conditioning and flotation stages in a batch extractor was determined by the surface properties of the clay minerals present. The water-continuous tailings stream was further separated into fine and coarse tailings fractions through sedimentation. The bulk of the clay minerals reported to the fine tailings stream. Illite and mixed layered illite-smectite partitioned less to the hydrocarbon-continuous froth than kaolinite. Also, the illite-smectite in the froth stream appeared to be different from the illite-smectite in the water continuous streams.