| 摘要 |
<p>Process for Recovering a Solid Bitumen Product from Tar Sands A principal object of the invention is to provide an economically feasible process for recovering bitumen from tar sands. The process comprises subjecting the tar sand having a particle size not in excess of about minus 1 inch to a drum leach with a light relatively volatile hydrocarbon solvent, centrifuging the resulting slurry to separate the bitumen loaded solvent from sand and distilling the pregnant solvent to recover a solid flaked bitumen product with almost complete recovery of solvent. As shown in the drawing, the solids from the centrifuging step are further processed in a series of successive agitation leach and centrifuging steps as recovered solvent and make up solvent are added to the system, the bitumen loaded solvent from the second centrifuging step being returned to the first leaching step. Solids from the final centrifuging step are thermally distilled and the recovered solvent returned to the system. As a result of the further processing, a high recovery of bitumen is obtained and the pregnant solution sent to solvent and bitumen separation for final solid bitumen recovery is substantially free of fines and particles.</p> |
