Crystal melting with heat pump and heated mother liquid

Claim 1

IN A PROCESS FOR SEPARATING A FLUID MIXTURE WHEREIN THE MIXTURE IS COOLED TO CRYSTALLIZE A PORTION THEREOF TO FORM CRYSTALS AND UNCRYSTALLIZED MOTHER LIQUOR, THE CRYSTALS AND MOTHER LIQUOR ARE PASSED THROUGH A FILTRATION ZONE TO REMOVE MOTHER LIQUOR, THE REMAINING CRYSTALS ARE PASSED THROUGH A PURIFICATION ZONE TO A MELTING ZONE WHEREIN CRYSTALS ARE MELTED, A PORTION OF THE RESULTING MELT IS REMOVED, AND THE REMAINDER OF THE CRYSTAL MELT IS PASSED BACK INTO THE CRYSTALS IN THE PURIFICATION ZONE; A COMBINED COOLING AND HEATING PROCESS WHICH COMPRISES PASSING A VOLATILE LIQUID REFRIGERANT IN HEAT EXCHANGE RELATIONSHIP WITH THE LIQUID MIXTURE TO PROVIDE COOLING OF THE MIXTURE, PASSING AT LEAST A PORTION OF THE SPENT REFRIGERANT IN HEAT EXCHANGE RELATIONSHIP WITH A HEATING FLUID TO WARM THE HEATING FLUID AND COOL THE REFRIGERANT, PASSING THE RESULTING WARMED HEATING FLUID IN HEAT EXCHANGE RELATIONSHIP WITH CRYSTALS IN THE MELTING ZONE TO PROVIDE HEAT TO MELT CRYSTALS, HEATING A PORTION OF THE MOTHER LIQUOR REMOVED FROM THE FILTRATION ZONE, AND PASSING THE THUS HEATED MOTHER LIQUOR IN HEAT EXCHANGE RELATIONSHIP WITH CRYSTALS IN THE MELTING ZONE TO PROVIDE ADDITIONAL HEAT TO MELT CRYSTALS.