초록 ▼

There is described a process based on unit operations conventionally employed but modified to enable the use of chlorinated solvents, particularly methylene chloride as the preferred solvent for extraction of the bitumen from the tar sands or shale. The process in general constitutes: I. an extracti

There is described a process based on unit operations conventionally employed but modified to enable the use of chlorinated solvents, particularly methylene chloride as the preferred solvent for extraction of the bitumen from the tar sands or shale. The process in general constitutes: I. an extraction operation wherein the tar sand is contacted with the chlorinated solvent, particularly methylene chloride, to extract (dissolve) the bitumen from the sand; II. a separation of the sand from the solvent bitumen extract; III. (a) recovery of the bitumen free of extractant; (b) recovery of the sand free of extractant.

대표청구항 ▼

A process for recovering bitumen from tar sands which comprises: (1) extracting bitumen from tar sand by mixing in co-current flow the tar sand with chlorinated hydrocarbons which may contain bitumen, (2) withdrawing from said extracting step a chlorinated hydrocarbons bitumen extract containing fro

A process for recovering bitumen from tar sands which comprises: (1) extracting bitumen from tar sand by mixing in co-current flow the tar sand with chlorinated hydrocarbons which may contain bitumen, (2) withdrawing from said extracting step a chlorinated hydrocarbons bitumen extract containing from about 20 to 50 weight percent bitumen, (3) rinsing in a counter current manner the extracted tar sand with chlorinated hydrocarbons to remove residual bitumen and forwarding a portion of said rinse composition to step 1, (4) drying the sand from step 3 in a heated steam purged drying zone, (5) recovering the solvent vaporized in step 4 and returning it to the process, (6) recovering the extracting solvent from the solvent bitumen extractor by treating the extract of step 2 to remove sand fines, distilling the major portion of the solvent, and then mixing the resulting bitumen containing a small portion of the solvent with a higher boiling hydrocarbon while removing the chlorinated hydrocarbon thereby to obtain a bitumen substantially free of chlorinated hydrocarbon but containing sufficient hydrocarbon to be pumpable.