Oil sands solids wettability and its relation to oil sands processability

One of the major steps in the extraction of bitumen from oil sands using the Clark Hot Water Extraction process is the liberation of bitumen from sand grains. In this study, flotation tests were performed to determine the processability of different oil sands ores and to isolate the solids from the oil sands. A jar shaking test was developed to quickly estimate the processability of the oil sand ores. The wettability of coarse solids (-250 +106 mum) and fine solids (-45 mum) was determined separately. The wettability of the coarse solids was measured by using a film flotation technique and an oil-water partitioning test. Coarse solids washed with both ethanol and toluene were less hydrophobic compared to those washed with ethanol or toluene alone, and drying increased the hydrophobicity of the coarse solids. The coarse solids washed with ethanol after drying were more hydrophobic than those washed with ethanol before drying. A water drop penetration test and an initial contact angle measurement were used to characterize the wettability of the fine solids. The wettability of the solids extracted from oil sands correlates well with the processability or bitumen recovery. In general, the more hydrophobic the solids are the poor, the processability of oil sands ore.