Process for extraction of phenol from aqueous mixtures

Claim 1

IN A PROCESS FOR THE SEPARATION OF PHENOL FROM A DILUTE AQUEOUS PHENOL SOLUTION WHEREIN SAID SOLUTION IS SUBJECTED TO LIQUID-LIQUID COUNTERCURRENT EXTRACTION WITH AN ORGANIC SOLVENT CONSISTING ESSENTIALLY OF DIISOPROPYL ETHER UNDER CONDITIONS RESULTING IN THE FORMATION OF AN EXTRACT PHASE CONSISTING ESSENTIALLY OF DIISOPROPYL ETHER IN ADMIXTURE WITH PHENOL FREE OF ANY SUBSTANTIAL AMOUNT OF WATER AND A RAFFINATE PHASE CONSISTING ESSENTIALLY OF WATER FREE OF ANY SUBSTANTIAL AMOUNT OF PHENOL, THE IMPROVEMENT WHICH COMPRISES ADJUSTING THE HYDROGEN ION CONCENTRATION OF SAID AQUEOUS PHENOL SOLUTION TO A PH OF FROM 5 TO 9 AND ADDING SODIUM CHLORIDE TO SAID ADJUSTED AQUEOUS PHENOL SOLUTION IN CONTROLLED AMOUNT TO OBTAIN A CONCENTRATION OF NACL OF FROM ABOUT 3 TO ABOUT 20% BY WEIGHT IN SAID AQUEOUS PHENOL SOLUTION PRIOR TO SUBJECTING SAID AQUEOUS PHENOL SOLUTION TO SAID EXTRACTION.