Stabilization of iron-containing acidic hydrogen peroxide solutions
AssigneeFMC Corporation
InventorDonald Charles Winkley
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Abstract
Aqueous, highly acidic solutions of hydrogen peroxide (pH under 2.0) containing iron contamination at the level of 30 to 30,000 ppm, are stabilized against undesired hydrogen peroxide decomposition by the dissolution therein of amino(methyl phosphonic acid)s or their soluble salts. Additional stabilizers are desirably used when other metallic contaminants are present.
Claims7
In the process of using hydrogen peroxide in aqueous mineral acid compositions at a pH below 2.0, in which the acid is selected from the group consisting of sulfuric, nitric and phosphoric acids, and the composition is relatively free of halide, but contains dissolved ferric iron in amounts between 30 ppm and 30,000 ppm, the method of retarding the decomposition of the hydrogen peroxide induced by the iron which comprises precipitating almost all of the dissolved iron by contacting it with an amino(methyl phosphonic acid) in solution in the composition, using at least three phosphonic acid groups for each ferric iron ion present.
Dependencies are inferred from the claim text.