Treatment of bituminous sands

Claim 1

IN A PROCESS FOR THE RECOVERY OF HYDROCARBON VALUES FROM NATURALLY-OCCURRING HYDROCARBONACEOUS MINERAL SOLIDS WHEREIN SAID SOLIDS ARE AGITATED IN A PULPING ZONE WITH AQUEOUS SODIUM SILICATE AND A LIQUID HYDROCARBON DILUENT AT A MODERATELY ELEVATED TEMPERATURE FOR A PERIOD OF TIME SUFFICIENT TO FORM A SUBSTANTIALLY HOMOGENEOUS FLUID PULP, AND SAID PULP IS THEREAFTER TREATED TO SEPARATE THEREFROM A HYDROCARBON PHASE, AN AQUEOUS PHASE, AND ESSENTIALLY OIL-FREE SOLIDS, THE METHOD OF EFFECTING SAID SEPARATION WHICH COMPRISES: (1) INTRODUCING SAID PULP INTO THE UPPER END OF A VERTICALLY ELONGATED PRIMARY SEPARATION ZONE, (2) ALLOWING THE SOLIDS COMPONENTS OF SAID PULP TO DESCEND BY GRAVITY THROUGH SAID SEPARATION ZONE TO THE LOWER END THEREOF, (3) PASSING A STREAM OF AQUEOUS SODIUM SILICATE UPWARDLY THROUGH SAID SEPARATION ZONE IN INTIMATE COUNTERCURRENT CONTACT WITH THE DESCENDING SOLIDS THEREIN, (4) WITHDRAWING A LIQUID PHASE COMPRISING HYDROCARBONS AND AQUEOUS SODIUM SILICATE FROM THE UPPER END OF SAID SEPARATION ZONE, (5) REMOVING DE-OILED SOLIDS FROM THE LOWER END OF SAID SEPARATION ZONE, (6) WASHING SAID DE-OILED SOLIDS WITH WATER TO OBTAIN SUBSTANTIALLY OIL-FREE SOLIDS AND A WASH LIQUOR COMPRISING WATER, SILT, AND HYDROCARBONS, (7) INTRODUCING SAID WASH LIQUOR INTO THE LOWER PART OF A STRATIFICATION ZONE WHICH OPENS DOWNWARDLY INTO A SURROUNDING CLARIFICATION ZONE, (8) INTRODUCING THE LIQUID PHASE OBTAINED IN STEP (4) INTO THE UPPER PART OF SAID STRATIFICATION ZONE, (9) MAINTAING THE LIQUID WITHIN SAID STRATIFICATION ZONE IN A QUIESCENT STATE, WHEREBY IS SEPARATES INTO AN UPPER HYDROCARBON PHASE AND A LOWER AQUEOUS PHASE, (10) WITHDRAWING SAID UPPER HYDROCARBON PHASE FROM THE UPPER END OF SAID STRATIFICATION ZONE AND WITHDRAWING SAID LOWER AQUEOUS PHASE FROM THE UPPER END OF SAID CLARIFICATION ZONE AT SUCH RATES, RELATIVE TO EACH OTHER, THAT THE INTERFACE BETWEEN SAID PHASES IS MAINTAINED AT A LEVEL BETWEEN THE LEVELS AT WHICH THE SAID LIQUID PHASE AND SAID WASH LIQUOR ARE INTRODUCED INTO SAID CLARIFICATION ZONE, AND (11) WITHDRAWING A THICKENED SLURRY OF SILT FROM THE BOTTOM OF SAID CLARIFICATION ZONE.