Method and apparatus for extracting bitumen from an oil sand stream

Abstract

The present invention provides a method for extracting bitumen from an oil sand stream, the method including the steps of: (a) providing an oil sand stream; (b) contacting the oil sand stream with a solvent thereby obtaining a first solvent-diluted oil sand slurry; (c) screening the first solvent-diluted oil sand slurry, thereby obtaining a first oversized material and a first undersized material; (d) contacting the first oversized material with a solvent thereby obtaining a second solvent-diluted oil sand slurry; (e) screening the second solvent-diluted oil sand slurry, thereby obtaining a second oversized material and a second undersized material; (f) optionally filtering the first undersized material obtained in step (c), thereby obtaining a solids-depleted stream and a solids-enriched stream; (g) optionally removing solvent from the solids-depleted stream obtained in step (f) thereby obtaining a bitumen-enriched stream.

What is claimed is: 
     
         1 . A method for extracting bitumen from an oil sand stream, the method comprising at least the steps of:
 (a) providing an oil sand stream;   (b) contacting the oil sand stream with a solvent thereby obtaining a first solvent-diluted oil sand slurry;   (c) screening the first solvent-diluted oil sand slurry, thereby obtaining a first oversized material and a first undersized material;   (d) contacting the first oversized material with a solvent thereby obtaining a second solvent-diluted oil sand slurry;   (e) screening the second solvent-diluted oil sand slurry, thereby obtaining a second oversized material and a second undersized material;   (f) optionally filtering the first undersized material obtained in step (c), thereby obtaining a solids-depleted stream and a solids-enriched stream;   (g) optionally removing solvent from the solids-depleted stream obtained in step (f) thereby obtaining a bitumen-enriched stream.   
     
     
         2 . The method according to  claim 1 , wherein the solvent in step (b) comprises a non-aqueous solvent. 
     
     
         3 . The method according to  claim 1 , wherein the solvent in step (d) comprises a non-aqueous solvent. 
     
     
         4 . The method according to  claim 1 , wherein the first undersized material obtained in step (c) is combined with the second undersized material obtained in step (e), before being filtered in step (f). 
     
     
         5 . An apparatus for performing the method according to  claim 1 , at least comprising:
 a housing containing a first section, a second section, a third section and a fourth section;   the first section having a first inlet for oil sand, a second inlet for a solvent and an outlet for a first solvent-diluted oil sand slurry;   the second section having an inlet for the first solvent-diluted oil sand slurry, a screen allowing a first undersized material to pass and an outlet for a first oversized material; and   the third section having a first inlet for the first oversized material, a second inlet for a solvent and an outlet for a second solvent-diluted oil sand slurry;   the fourth section having an inlet for the second solvent-diluted oil sand slurry, a screen allowing a second undersized material to pass and an outlet for a second oversized material;
 wherein the first section, the second section, the third section and the fourth section can rotate during use around a common rotation axis (A-A′). 
   
     
     
         6 . The apparatus according to  claim 5 , wherein the screen of the second section and the housing define an annular pathway arranged around the screen for removing the first undersized material passed through the screen. 
     
     
         7 . The apparatus according to  claim 5 , wherein the screen of the fourth section and the housing define an annular pathway arranged around the screen for removing the second undersized material passed through the screen. 
     
     
         8 . The apparatus according to  claim 6 , wherein the annular pathway is fluidly connected to an inlet of a filtration unit. 
     
     
         9 . The apparatus according to  claim 5 , comprising a threshold between the first section and second section. 
     
     
         10 . The apparatus according to  claim 5 , comprising a threshold between the third section and fourth section. 
     
     
         11 . The apparatus according to  claim 5 , comprising an inner screen which is concentrically arranged with respect to the screen of the second section and the screen of the fourth section. 
     
     
         12 . The apparatus according to  claim 11 , wherein the inner screen connects the outlet of the first section to the outlet of the fourth section.