Abstract:
TION OF THE MOBILE BED IN THE EXTRACTION ZONE AND INTRO DUCING IT INTO AN ELUTRIATION ZONE WHEREIN A MOBILE BED OF SAND IS MAINTAINED IN A RISING WATER STREAM, WITHDRAWING LIQUID FROM THE UPPER PORTION OF THE ELUTRIATION ZONE, SEPARATING IT INTO A WATER-PHASE AND A HYDROCARBON PHASE, RETURNING THE HYDROCARBON PHASE TO THE EXTRACTION ZONE, RETURNING WATER PHASE TO THE ELUTRIATION ZONE, AND WITHDRAWING WATER AND SAND FROM THE LOWER PORTION OF THE ELUTRATION ZONE.
SEPARATING TAR FROM SAND IN A PROCESS WHERE FINES ARE EXCLUDED FROM THE PRODUCT WITH MINIMUN PARTICLE SEPARATION EQUIPMENT AND SOLVENT LOSSES TO THE SEPARATED SAND ARE VERY SMALL, INCLUDING MAINTAINING A MOBILE BED OF SAND PARTICLES IN A RISING SOLVENT STREAM IN AN EXTRACTION ZONE, WITHDRAWING A SOLVENT-TAR MIXTURE THROUGH A PASSAGEWAY THAT STARTS LATERALLY WITHIN THE MOBILE BED AND TERMINATES ABOVE IT, THE MIXTURE BEING LOW IN FINES DUE TO THE FILTERING ACTION OF THE MOBILE BED, AND SUBJECTING THE SOLVENT-TAR STREAM TO PARTICLE SEPARATION AND SOLVENT RECOVERY, REMOVING A SAND-SOLVENT STREAM FROM A LOWER POR-