PROCESS FOR REMOVING SOLVENT FROM AN UNDERFLOW STREAM FROM THE LAST SEPARATION STEP IN AN OIL SANDS FROTH TREATMENT PROCESS

摘要

A process is described for treating an underflow stream containing water, solvent, asphaltenes and solids, from one of the last separation steps in a paraffinic solvent process for separating bitumen from an oil sands froth, wherein a) the stream is introduced to a solvent recovery vessel that is substantially free of internals wherein the temperature and pressure are such that the solvent is normally a vapour, b) a pool of liquid and solids is maintained in the lower part of the vessel at a controlled level for sufficient time to allow the solvent to vapourize, c) the pool is agitated to the point where the asphaltenes are dispersed, submerged and prevented from re-agglomerating and the solids are maintained in suspension, d) the solvent is recovered as an overhead vapour stream, and e) the solvent depleted remainder of the stream is removed from the bottom of the vessel as a liquid slurry.