Process for purifying crude acetone

Claim 1

THE PROCESS FOR THE PURIFICATION OF THE CRUDE ACETONE OBTAINED BY THE DECOMPOSITION OF CUMENE HYDROPEROXIDE AND CONTAINING ALDEHYDES, ESTER, ACETALS, MESITYL OXIDE AND SULPHUR COMPOUNDS AS IMPURITIES WHICH COMPRISES CONTINUOUSLY INTRODUCING SAID ACETONE AT A RATE IN THE RANGE OF ABOUT 5 TO ABOUT 10 GALLONS PER MINUTE INTO AN ALDEHYDIC STRIPPING COLUMN WHEREIN THE MAJOR PART OF THE ALDEHYDIC IMPURITIES IS REMOVED, ALSO CONTINUOUSLY INTRODUCING INTO SAID COLUMN AN AQUEOUS SOLUTION OF ABOUT 5 TO ABOUT 25% CONCENTRATION OF AN ALKALI METAL HYDROXIDE SELECTED FROM THE GROUP CONSISTING OF SODIUM HYDROXIDE AND POTASSIUM HYDROXIDE, THE AQUEOUS HYDROXIDE SOLUTION BEING INTRODUCED AT A RATE VARYING BETWEEN ABOUT 5 GALLONS PER HOUR WHEN THE CONCENTRATION IS ABOUT 5% AND ABOUT 1 GALLON PER HOUR WHEN THE CONCENTRATION IS ABOUT 25%, CONTINUOUSLY WITHDRAWING FROM THE BASE OF SAID COLUMN A MIXTURE OF CRUDE ACETONE AND ALKALI METAL HYDROXIDE SOLUTION, CONTINUOUSLY FEEDING SAID MIXTURE INTO A FRACTIONAL DISTILLATION COLUMN AT AN INTERMEDIATE POINT IN SAID COLUMN, AND REMOVING PURE ACETONE AS AN OVERHEAD STREAM FROM SAID FRACTIONAL DISTILLATION COLUMN.