GB1498008A - Separation of bitumen from tar sands - Google Patents

Abstract

1498008 Separation of bitumen from tar sand MAGNA INTERNATIONAL Inc 23 Jan 1975 [24 Jan 1974] 3395/74 Heading C5E Tar sand is mixed with water to form a slurry, the slurry is agitated and diluted with water to form a pulp having a water content at least equal to the weight of the tar sand and a temperature of at least 35‹ C., the pulp is moved primarily horizontally within a separating zone at a speed which is low enough to allow gravity settling of bitumen-free sand to form a sand bed in contact with the horizontally moving pulp but high enough to prevent permanent settling of bitumen coated sand, so that the bitumen coated sand is freed from bitumen by tumbling along the upper surface of the bed, sand is withdrawn from the bottom of the separating zone and water containing fines and bitumen is removed from the upper portion of the separating zone. Fig. 1 illustrates an apparatus in which a mixer 2 is used to form a slurry of tar sand 1 in water 3. Freed oil is skimmed from the surface of the slurry at 5 and 6 and the remaining slurry passed into a shoot 8 which discharges it between the inner stationary casing 13 (which has vanes 13a) and the upper portion of the inner rotating conical member 11 (which has vanes 19). The slurry is then rotated around the annular chamber formed between the outer casing 12 and the lower surface 15 of the cone 11 by the vanes 16 on the cone 11. The cleaned sand collects in a bed 37 at the base of the chamber and descending sand is freed from adhering bitumen by being tumbled over the surface 38 of the sand bed 37 by the swirling motion. A flow of recycled water from line 31 upwardly through the sand bed and the annular chamber removes the freed bitumen together with some adhering sand from the top of the chamber and into a collecting trough 30. Separated oil is skimmed from the trough at 35 and bitumen nodules are removed by a foraminous belt 32 through which the water passes and is recycled via line 31. The cleaned sand is continuously removed from the bed 37 by a screw auger 20. The sand/water slurry is suitably fed to the separator at 35-75‹ F.; a more complete separation of the bitumen from the sand can be achieved by mixing 10-20% (based on the weight of bitumen) of a solvent, such as kerosene or naphtha, with the tar sand prior to forming the slurry. Fig. 2 (not shown) illustrates an apparatus similar to that of Fig. 1 but in which the cleaned sand is removed by an auger located within the central shaft of the rotating conical member. Fig. 3 (not shown) illustrates an apparatus similar to that of Fig. 2 but in which the recycled water passes down through the hollow shaft of the sandremoving auger. Fig. 4 (not shown) illustrates an apparatus similar to that of Fig. 3 but in which the upper portion of the annular chamber shown in Fig. 1 is replaced by a very high turbulence slurry feed device.