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U.S. Department of Energy
Office of Scientific and Technical Information

Two-stage tar sands extraction process

Patent ·
OSTI ID:5602277

A method is described for extracting bitumen from tar sands, wherein the tar sands contain at least 3 weight percent connate water, comprising initially contacting the bitumen with a specific solvent in a first extraction stage and thereafter contacting the bitumen with both a nonspecific solvent and a specific solvent in a second extraction stage, whereby a bitumen product low asphaltenes and fines is obtained. A method is also described for extracting bitumen tar sands, wherein the tar sands contain less than 3 weight percent connate water, comprising: (a) initially slurrying the tar sand with a nonspecific solvent to dissolve a substantial portion of the available bitumen in a first extraction stage; (b) separating the bitumen-containing solvent from the slurry solids; (c) contacting the bitumen-containing solvent with a specific solvent to precipitate asphaltenes and fines in a second extraction stage; (d) separating the fines and the asphaltenes from the bitumen-containing solvents; and (e) recovering the bitumen from the solvents.

Assignee:
Standard Oil Co., Chicago, IL
Patent Number(s):
US 4596651
OSTI ID:
5602277
Country of Publication:
United States
Language:
English