US4059678A
Expired / Lapsed
US
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Stabilization of iron-containing acidic hydrogen peroxide solutions
Assignee: FMC Corp
•
Filing: 1973-02-02
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Granted: 1977-11-22
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Expires: 1993-02-02
Abstract
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.
Inventors
- 👤 Donald Charles Winkley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:35
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C01; C01B; C01B15/00; C01B15/01; C01B15/037; C23G; C23G1/00; C23G1/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
103 words
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.
Claim 2
Dependent Claim
103 words
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.
Claim 3
Dependent Claim
32 words
The method of claim 1, in which there is also present a stabilizer against decomposition by copper, whereby the composition can be used in the treatment of non-ferrous metals other than vanadium.
Claim 4
Dependent Claim
14 words
The method of claim 1, in which the amino(methyl phosphonic acid) is amino-tri-(methylphosphonic acid).
Claim 5
Dependent Claim
16 words
The method of claim 1, in which the amino(methyl phosphonic acid) is ethylenediamine tetra(methyl phosphonic acid).
Claim 6
Dependent Claim
16 words
The method of claim 1, in which the amino(methyl phosphonic acid) is hexenediamine tetra(methyl phosphonic acid).
Claim 7
Dependent Claim
16 words
The method of claim 1, in which the amino(methyl phosphonic acid) is dodecylamino bis(methyl phosphonic acid).
Claim 8
Dependent Claim
13 words
The method of claim 2, in which the stabilizer for copper is phenol.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-21 | 1981-05-23 | 1981-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-21 | 1985-05-23 | 1985-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-21 | 1989-05-23 | 1989-11-22 | $7700.00 | Window Closed / Lapsed |