Separation of eutectic-forming mixtures by crystallization methods

Claim 1

A PROCESS FOR SEPARATING THE COMPONENTS OF A BINARY MIXTURE OF ORGANIC COMPOUNDS WHICH FORM A BINARY EUTECTIC AND WHICH ARE COMPLETELY MISCIBLE IN THE LIQUID PHASE AND COMPLETELY IMMISCIBLE IN THE SOLID PHASE WHICH COMPRISES THE STEPS OF PASSING THE LIQUID MIXTURE CONTAINING AN EXCESS OF A SATURATING COMPONENT INTO A FIRST ELONGATED SEPARATION ZONE; MAINTAINING THE BOTTOM OF SAID FIRST SEPARATION ZONE AT A TEMPERATURE ABOVE THE EUTECTIC TEMPERATURE FOR THE BINARY MIXTURE AND BELOW THE TOP TEMPERATURE, MAINTAINING THE TOP OF SAID FIRST SEPARATING ZONE AT A TEMPERATURE SUCH THAT THE SATURATING COMPONENT OF LESS THAN THE PREDETERMINED PURITY WILL BE MELTED BEFORE REACHING THE TOP AND MATERIAL OF THE DESIRED PURITY WILL REMAIN SOLID AT THE TOP, AND MAINTAINING THE INTERMEDIATE TEMPERATURES AT POINTS INTERMEDIATE THE TOP AND BOTTOM OF SAID FIRST SEPARATION ZONE; ABSTRACTING HEAT FROM SAID MIXTURE TO SOLIDIFY A PORTION OF SAID MIXTURE; PASSING SAID SOLID UPWARD THROUGH SAID FIRST SEPARATION ZONE; SUBJECTING THE UPWARDLYMOVING SOLID TO A PLURALITY OF SOLID-LIQUID EQUILIBRIUM CONTACTS WITH A LIQUID WHICH IS INCREASINGLY RICHER WITH RESPECT TO THE SATURATING COMPONENT OF SAID BINARY MIXTURE, WHEREBY THE SOLID IS MADE INCREASINGLY RICHER WITH RESPECT TO SAID SATURATING COMPONENT AS IT APPROACHES THE TOP OF SAID FIRST SEPARATION ZONE AND THE DESCENDING REFLUX LIQUID IS MADE TO APPROACH THE BINARY EUTETIC COMPOSITION AS IT DESCENDS; REMOVING THE SOLIDIFIED SATURATING COMPONENT AS OVERHEAD PRODUCT, THE AMOUNT OF SAID SATURATING COMPONENT REMOVED AS A SOLID OVERHEAD PRODUCT BEING SUFFICIENT THAT THE ADDITION OF A DILUENT TO THE REMAINING LIQUID WILL PRODUCE A TERNARY MIXTURE HAVING A GREATER EXCESS OF SATURATING COMPONENT THAN THE BINARY MIXTURE TO WHICH SAID DILUENT WAS ADDED; REMOVING A MIXTURE APPROXIMATING THE BINARY EUTECTIC COMPOSITION AS A LIQUID BOTTOM-PRODUCT; ADDING TO THE LIQUID BOTTOM PRODUCT A LIQUID DILUENT IN AN AMOUNT LESS THAN THAT REQUIRED TO SATURATE THE RESULTING TERNARY MIXTURE WITH RESPECT TO SAID DILUENT BUT SUFFICIENT TO PERMIT CRYSTALLIZATION OF A QUANTITY OF THE COMPONENT WITH RESPECT TO WHICH SAID TERNARY MIXTURE IS SATURATED, SAID LIQUID DILUENT BEING SUCH THAT THE FREEZING POINT OF ONE OF THE COMPONENTS OF SAID LIQUID BOTTOM-PRODUCT IS LOWERED MORE THAN THE OTHER; PASSING THE TERNARY MIXTURE SO FORMED INTO A SECOND SEPARATION ZONE; ABSTRACTING HEAT FROM SAID MIXTURE TO SOLIDIFY A PORTION OF THE THEN SATURATING COMPONENT; PASSING THE SOLID UPWARDLY THROUGH SAID SECOND SEPARATION ZONE WHILE SUBJECTING IT TO A PLURALITY OF SOLID-LIQUID CONTACTS WITH A REFLUX LIQUID WHICH IS INCREASINGLY RICHER WITH RESPECT TO THE SATURATING COMPONENT OF SAID TERNARY MIXTURE; REMOVING THE SOLIDIFIED MATERIAL OVERHEAD AND REMOVING THE REMAINING LIQUID FROM THE BOTTOM OF SAID SECOND SEPARATION ZONE; REMOVING THE DILUENT FROM THE BOTTOM PRODUCT; PASSING THE DILUENTFREE LIQUID TO A SEPARATION ZONE; ABSTRACTING HEAT FROM SAID LIQUID TO SOLIDIFY A PORTION OF THE SATURATING COMPONENT; PASSING THE SOLID UPWARDLY THROUGH SAID LAST-NAMED SEPARATION ZONE WHILE SUBJECTING IT TO A PLURALITY OF SOLID-LIQUID CONTACTS WITH A REFLUX LIQUID THAT IS INCREASINGLY RICHER WITH RESPECT TO THE COMPONENT WITH RESPECT TO WHICH SAID MIXTURE IS SATURATED; REMOVING THE SOLIDIFIED MATERIAL AS A SOLID OVERHEAD PRODUCT AND THE LIQUID OF NEAR EUTECTIC COMPOSITION AS A LIQUID BOTTOM PRODUCT, IN THE MANNER DESCRIBED FOR THE FIRST SEPARATION, AND RECYCLING THE LAST-NAMED LIQUID BOTTOMS PRODUCT.