| Description |
This research project concentrates on the design and development of a pilot plant to extract bitumen from Utah tar sands with the minimum loss of water, taking into consideration the environmental parameters of this area through a modified hot water process. Although the hot water process is being used in Canada for the extraction of bitumen, the basic differences in the overall properties between the two tar sands, rule out the application of the Canadian hot water process to Utah tar sands, and warrant an appropriately modified hot water process technology specifically suitable to process Utah tar sands. Accordingly, a new process has been suggested to achieve the research goals and obviating the necessity of a tailings pond. To recover maximum water, solids are divided into two streams of +65 mesh and 65 mesh and dewatered separately. This modified process envisages the use of major equipment in the form of a new three-product, open-top hydrocyclone, a high-density thickener, and a spiral classifier. Three-product hydrocyclone is a new unit. An 11-inch plastic model of a new three-product, open-top hydrocyclone was conceived and constructed primarily to determine the flow pattern. This was tested with sand and water. The flow pattern was determined using a pitot tube. It was distinctly observed that unlike the two-product conventional hydrocyclone, where a free-vortex pattern exists, forced-vortex pattern for tangential component of velocity was confirmed. In the pilot plant, a 30-inch diameter three-product, open-top hydrocyclone was constructed and tested with a slurry containing bitumen, water, and sand. Bitumen has a specific gravity very close to one, it is very difficult to separate it from water. Since bitumen is known to have an affinity for attachment to air, fine bubbles of air were injected in the feed pipe of the three-product, open-top hydrocyclone to alter its specific gravity. The air thus injected attached to the bitumen and caused it to float in subsequent steps. More than 90% bitumen was recovered in the overflow and middling streams. Injection of air caused more bitumen to report at the overflow stream. |
