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US 4,070,442 AGranted
Stabilized hydrogen peroxide
AssigneeE. I. Du Pont de Nemours and Company
InventorJohn Conway Watts
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AssigneeE. I. Du Pont de Nemours and Company
InventorJohn Conway Watts
Estimating the term…
Aqueous hydrogen peroxide solutions containing (1) an organophosphorus compound selected from the group consisting of alkylidene diphosphonic acids, aminotri(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid), and soluble alkali metal salts of the foregoing acids an (2) and organic hydroxy compound selected from allyl alcohol, methallyl alcohol, phenol, o-chlorophenol, o-nitrophenol, o-aminophenol, p-chlorophenol, p-nitrophenol, p-aminophenol, and mixtures thereof are stable during use over a pH range of about 0.5 to 10 against catalytic decomposition by heavy metal ions and by surfaces of insoluble heavy metal sulfides. The stabilizer combinations of this invention are apparently synergistic and give unexpected hydrogen peroxide stability. The stabilized hydrogen peroxide solutions of the invention are especially useful in hydrometallurgical processes and in mineral separations and purifications.
An aqueous hydrogen peroxide solution having improved stability in the presence of heavy metal ions and insoluble heavy metal sulfides containing from 3-70 weight percent hydrogen peroxide;
A method of stabilizing an aqueous hydrogen peroxide solution containing 3 to 70 weight percent hydrogen peroxide against decomposition in the presence of heavy metal ions and insoluble heavy metal sulfides comprising adding to the aqueous hydrogen peroxide solution an alkylidene diphosphonic acid having the formula ##STR4## wherein X is hydrogen or the hydroxyl radical and n is a whole number from 0 to 5 or soluble alkali metal salts thereof;
A method of claim 5 wherein the hydrogen peroxide concentration is from about 35 to 50 weight percent, and the organic hydroxy compound is phenol or allyl alcohol.
Dependencies are inferred from the claim text.