Process for recovery of solvent from tar sand bitumen

patentThere 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