Chemical treatment of athabaska froth

Claim 1

PROCESS FOR THE SEPARATION OF BITUMEN FROM TAR SANDS WHICH COMPRISES CONTACTING THE SANDS IN AN INTIAL STAGE WITH ABOUT 0.5 TO 2.0 VOLUMES OF WATER PER VOLUME OF TAR SANDS AT A TEMPERATURE IN THE RANGE FROM ABOUT 140* F. TO 200*F., WHEREBY SANDS SEPARATE AND A FROTH IS FORMED CONTAINING FROM ABOUT 5 TO 25% BY WEIGHT OF SOLIDS OF WHICH ABOUT 30 TO 80% ARE HEAVY MINERALS; REMOVING THE SANDS FROM SAID INITIAL STAGE AND PASSING THE FROTH CONTAINING SAID HEAVY MINERALS TO A SECONDARY STAGE AND COUNTERCURRENTLY CONTACTING THE SAME IN THE SECONDARY STAGE WITH 0.5 TO 1.5 VOLUMES OF ADDITIONAL WATER PER VOLUME OF FROTH, SAID ADDITIONAL WATER CONTAINING A CHELATING AGENT PRESENT IN A CONCENTRATION OF 0.01 TO 0.5% BY WEIGHT BASED ON THE FROTH AND A TRANSJFER AGENT PRESENT IN A CONCENTRATION OF ABOUT 0.1 TO 2.0% BY WEIGHT BASED UPON THE FROTH WHEREBY SUBSTANTIALLY ALL THE REMAINING SANDS ARE REMOVED FROM THE FROTH; WITHDRAWING THE FROTH FROM THE UPPER AREA OF SAID SECONDARY STAGE AND PASSING THE FROTH TO A TERTIARY STAGE AND CONTACTING THE SAME IN SAID TERTIARY STAGE WITH A DEMULSIFYING AGENT TO PRODUCE A SUBSTANTIALLY WATER-FREE OIL PHASE.