Patent ID: 6649139
Filing Date: 2003-11-18
Classification: C01B

Abstract:
A process for producing a purified aqueous hydrogen peroxide solution by removing silicon oxide impurities contained in an aqueous hydrogen peroxide solution, which comprises:adding a flocculating agent to an aqueous hydrogen peroxide solution containing silicon oxide impurities, and filtering out impurities of solid content contained in the aqueous hydrogen peroxide solution with a precision filter, thereafter bringing the aqueous hydrogen peroxide solution obtained as above into contact with an anion exchange resin in a fluoride ion form changed by at least one fluoride compound which contains 0.05% by weight or less of SiF6 and is selected from the group consisting of sodium fluoride, potassium fluoride and ammonium fluoride, wherein the flocculating agent is a phosphorus compound, and the phosphorus compound is added in an amount that the atomic ratio (Si/P) of silicon oxide impurities contained in the aqueous hydrogen peroxide solution in terms of silicon atom to phosphorus compound in terms of phosphorus atom is 0.0001 or less.