Dewaxing mineral oils

Claim 1

IN A METHOD OF DEWAXING A WAXY MINERAL OIL, THE COMBINATION OF STEPS COMPRISING: (1) MIXING THE WAXY MINERAL OIL WITH A SUBSTANTIAL PROPORTION OF A DEWAXING SOLVENT WHICH IS A SOLVENT FOR THE MINERAL OIL BUT WHICH IS SUBSTANTIALLY A NON-SOVENT FOR SOLID WAX, AND ADJUSTING THE TEMPERATURE OF THE MIXTURE TO OBTAIN A SINGLE LIQUID PHASE OF THE SOLVENT, OIL AND WAX; (2) COOLING THE MIXTURE TO A DEWAXING TEMPERATURE AT WHICH THE WAX SOLIDIFIES, THEREBY FORMING A DISPERSION OF SOLID WAX PARTICLES IN A LIQUID OIL PHASE WHICH IS A SOLUTION OF THE OIL AND THE SOLVENT; (3) INTIMATELY MIXING THE RESULTING DISPERSION OF SOLID WAX DISPERSED IN THE OIL PHASE WITH A SUBSTANTIAL PROPORTION, AT LEAST EQUAL IN VOLUME TO THE VOLUME OF THE OIL PHASE, OF A SUBSTANTIALLY POLAR AUXILIARY LIQUID WHICH IS SUBSTANTIALLY IMMISCIBLE THEREWITH AND WHICH HAS A DIELECTRIC CONSTANT HIGHER THAN THAT OF THE OIL PHASE, THE AUXILIARY LIQUID BEING ESSENTIALLY AT THE DEWAXING TEMPERATURE, AND WITH A MINOR AMOUNT OF A SURFACE-ACTIVE AGENT, WHEREBY TWO LIQUID PHASES RESULT, AN OIL PHASE CONSISTING ESSENTIALLY OF MINERAL OIL AND SOLVENT AND AN AUXILIARY LIQUID PHASE CONTAINING DISSOLVED SAID SURFACE-ACTIVE AGENT, AND CORRELATING THE DIELECTRIC CONSTANTS OF THE TWO LIQUID PHASES SO THAT THE CONTACT ANGLE IN THE OIL PHASE IS AT LEAST 90*, WHEREBY THE SOLID WAX IN THE AUXILIARY BY THE AUXILIARY LIQUID PHASE AND IS TRANSFERRED THERETO TO PRODUCE A DISPERSION OF THE SOLID WAX IN THE AUXILIARY LIQUID PHASE AS CONTINUOUS PHASE, WHILE THE OIL PHASE IS SUBSTANTIALLY FREED FROM SOLID WAX; (4) STRATIFYING AND SEPARATING THE OIL PHASE FROM THE AUXILIARY LIQUID PHASE CONTAINING THE DISPERSION OF SOLID WAX; (5) COMMINGLING THE WAX-CONTAINING AUXILIARY LIQUID PHASE WITH AN ORGANIC LIQUID, WHICH IS SUBSTANTIALLY LESS POLAR THAN SAID AUXILIARY LIQUID AND IS SUBSTANTIALLY IMMISCIBLE THEREWITH, UNDER CONDITIONS SUCH THAT THE CONTACT ANGLE OF THE SOLID WAX IN THE ORGANIC LIQUID PHASE IS LESS THAN 90*, WHEREBY THE WAX IS TRANSFERRED TO SAID ORGANIC LIQUID PHASE; AND (6) STRATFYING AND SEPARATING THE ORGANIC LIQUID PHASE CONTAINING THE WAX DISPERSED THEREIN FROM THE AUXILIARY LIQUID PHASE.