Recovery of oil from bituminous sands

Claim 1

THE PROCESS FOR TREATING BITUMINOUS SAND CONTAINING CRUDE OIL AND SILT WHICH COMPRISES INTRODUCING THE BITUMINOUS SAND INTO A SAND SEPARATION ZONE, INTRODUCTING HYDROCARBON DILUENT INTO SAID SEPARATION ZONE, TO FORM THEREIN A LOWER LAYER IF SAND AND AN UPPER LAYER OF CRUDE OIL, HYDROCARBON DILUENT AND SILT, REMOVING SAND CONTAIN ING ENTRAINED HYDROCARBON DILUENT FROM SAID LOWER LAYER OF THE SEPARATION ZONE AND PASSING SAME TO A SAND WASHING ZONE IN WHICH IT IS CONTACTED WITH WATER TO FORM IN SAID SAND WASHING ZONE A LOWER LAYER OF SAND, AN INTERMEDIATE LAYER OF WATER AND AN UPPER LAYER OF HYDROCARBONS, SEPARATELY REMOVING EACH OF SAID LAYERS FROM SAID SAND WASHING ZONE, PASSING AT LEAST A PORTION OF THE MIXTURE OF CRUDE OIL, HYDROCARBON DILUENT AND SILT REMOVED FROM THE UPPER LAYER OF THE SAND SEPARATION ZONE TO A FIRST SILT SETTLING ZONE TO FORM THEREIN A LOWER LAYER OF SILT AND AN UPPER LAYER OF HYDROCARBON DILUENT AND CRUDE OIL, REMOVING HYDROCARBON DILUENT AND CRUDE OIL FROM THE UPPER LAYER OF THE FIRST SILT SETTLING ZONE AND PASSING SAME TO A COKING ZONE WHEREIN THE SAME IS TREATED UNDER COKING CONDITIONS TO PRODUCE COKE AND LIQUID HYDROCARBON PRODUCT, WITHDRAWING SILT CONTAINING ENTRAINED HYDROCARBON DILUENT AND CRUDE OIL FROM THE LOWER PORTION OF THE FIRST SILT SETTLING ZONE AND PASSING SAME TO A SECOND SILT SETTLING ZONE, INTRODUCING ADDITIONAL HYDROCARBON DILUENT INTO SAID SECOND SILT SETTLING ZONE TO FORM THEREIN A LOWER LAYER OF SILT AND AN UPPER LAYER OF HYDROCARBON DILUENT,REMOVING HYDROCARBON DILUENT FROM THE UPPER PORTION OF SAID SECOND SILT SETTLING ZONE, REMOVING SILT CONTAINING ENTRAINED HYDROCARBON DILUENT FROM THE LOWER PORTION OF THE SECOND SILT SETTLING ZONE AND PASSING SAME TO A SILT WASHING ZONE, INTRODUCING WATER INTO SAID SILT WASHING ZONE TO FORM THEREIN A LOWER LAYER OF SILT, AN INTERMEDIATE LAYER OF WATER AND AN UPPER LAYER OF HYDROCARBON DILUENT, SEPARATELY REMOVING EACH OF SAID LAYERS FROM THE SILT WASHING ZONE, REMOVING COKE AND LIQUID HYDROCARBON PRODUCT FROM SAID COKING ZONE AND PASSING AT LEAST A PORTION OF SUCH LIQUID HYDROCARBON PRODUCT TO SAID SECOND SLIT SETTLING ZONE AS HYDROCARBON DILUENT.