Treatment of hydrogen peroxide working solution containing anthraquinone degradation products

Claim 1

A PROCESS FOR THE TREATMENT OF A WORKING SOLUTION COMPRISING AN ANTHRAQUINONE COMPOUND DISSOLVED IN AN ORGANIC SOLVENT, SAID WORKING SOLUTION HAVING BEEN SUBJECTED TO REPEATED REDUCTIONS AND OXIDATIONS FOR THE PRODUCTION OF HYDROGEN PEROXIDE AND CONTAINING ANTHRAQUINONE DEGRADATION PRODUCTS AND ALSO TETRAHYDROANTHAQUINONE COMPOUND RESULTING FROM REPEATED REDUCTIONS AND OXIDATIONS IN THE PRODUCTION OF HYDROGEN PEROXIDE, WHICH COMPRISES REMOVING THE ORGANIC SOLVENT FROM THE WORKING SOLUTION LEAVING AS RESIDUE A MIXTURE OF ANTHRAQUINONE COMPOUND, TETRAHYDROANTHRAQUINONE COMPOUND AND ANTHRAQUINONE DEGRADATION PRODUCTS, ADDING TO THE RESIDUE A STOICHIOMETRIC EXCESS OF AQUEOUS ALKALI AND A VOLATILE HYDROCARBON SOLVENT BOILING IN THE RANGE OF ABOUT 50-200*C. IN WHICH ANTHRAQUINONE COMPOUND AND TETRAHYDROANTHRAQUINONE COMPOUND WILL DISSOLVE, SUBJECTING THE RESULTANT MIXTURE TO HYDROGENATION TO REDUCE ANTHRAQUINONE AND TETRAHYDROANTHRAQUINONE COMPOUNDS TO THE ANTHRAHYDROQUINONE FORMS AND TO REACT ANTHRAHYDROQUINONE WITH ALKALI TO PRODUCE WATER-SOLUBLE ALKALI ANTHRAHYDROQUINONES, SEPARATING THE MIXTURE INTO AN AQUEOUS LAYER CONTAINING WATER-SOLUBLE ALKALI ANTHRAHYDROQUINONES AND A VOLATILE SOLVENT LAYER CONTAINING ANTHRAQUINONE DEGRADATION PRODUCTS, SEPARATING THE VOLATILE SOLVENT FROM THE ANTHRAQUINONE DEGRADATION PRODUCT, OXIDIZING THE WATER-SOLUBLE ALKALI ANTHRAHYDROQUINONES TO CONVERT THE ANTHAHYDROQUINONES TO ANTHRAQUINONES INSOLUBLE IN WATER, AND SEPARATING AND RECOVERING THE WATER-INSOLUBLE ANTHRAQUINONES FROM THE AQUEOUS LIQUOR.