US4437931A
Expired / Lapsed
US
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Dissolution of metals
Assignee: Plastic Specialties and Technologies Inc
•
Filing: 1983-08-22
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Granted: 1984-03-20
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Expires: 2003-08-22
Abstract
Abstract Improved metal dissolution rates are obtained when using a solution containing sulfuric acid, hydrogen peroxide and certain primary diols.
Inventors
- 👤 Moenes L. Elias
- 👤 Walter L. Burger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:00
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
133 words
In a process for the dissolution of metals in which a metal is contacted with an aqueous solution containing free chloride or bromide ions, from about 0.2 to about 4.5 gram moles per liter of sulfuric acid and from about 0.25 to about 8 gram moles per liter of hydrogen peroxide, the method of increasing the metal dissolution rate of the solution in the presence of chloride or bromide ions to a value higher than that obtained by such a solution free of any chloride and bromide ions, which method comprises adding an effective amount of a diol promoter having the general formula: ##STR2## where R 1 , R 2 , R 3 and R 4 can be either H, CH 3 , OC 2 H 5 or OC 3 H 8 .
Claim 2
Dependent Claim
133 words
In a process for the dissolution of metals in which a metal is contacted with an aqueous solution containing free chloride or bromide ions, from about 0.2 to about 4.5 gram moles per liter of sulfuric acid and from about 0.25 to about 8 gram moles per liter of hydrogen peroxide, the method of increasing the metal dissolution rate of the solution in the presence of chloride or bromide ions to a value higher than that obtained by such a solution free of any chloride and bromide ions, which method comprises adding an effective amount of a diol promoter having the general formula: ##STR2## where R 1 , R 2 , R 3 and R 4 can be either H, CH 3 , OC 2 H 5 or OC 3 H 8 .
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein said promoter is provided at a concentration of at least 0.01 gram moles per liter.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein said promoter is provided at a concentration in the range from about 0.1 to about 0.5 gram moles per liter.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein the aqueous solution contains sodium phenolsulfonate as a stabilizer to reduce the degrading effect of heavy metal ions on hydrogen peroxide.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein the hydrogen peroxide concentration is maintained between about 1 and about 4 gram moles per liter.
Claim 7
Dependent Claim
22 words
The method of claim 1 wherein the sulfuric acid concentration is maintained between about 0.3 and about 4 gram moles per liter.
Claim 8
Dependent Claim
10 words
The method of claim 1 wherein the promoter is 2-butyne-1,4-diol.
Claim 9
Dependent Claim
10 words
The method of claim 1 wherein the promoter is 3-hexyne-2,5-diol.
Claim 10
Dependent Claim
12 words
The method of claim 1 wherein the promoter is monopropoxylated 2 butyne-1,4-diol.
Claim 11
Dependent Claim
12 words
The method of claim 1 wherein the promoter is diethoxylated 2 butyne-1,4-diol.
Claim 12
Dependent Claim
15 words
The method of claim 1 wherein the metal is copper or an alloy of copper.
Claim 13
Dependent Claim
20 words
The method of claim 1 carried out in the presence of at least 2 ppm of free chloride or bromide.
Claim 14
Dependent Claim
38 words
The method of claim 1 wherein the concentration of the promoter is at least 0.2 gram moles per liter and the dissolution is carried out in the presence of at least 25 ppm of free chloride or bromide.
References Cited (Backward Citations)
US4141850A
Cited
US4174253A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-20 | 1987-09-19 | 1988-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-20 | 1991-09-19 | 1992-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-20 | 1995-09-19 | 1996-03-20 | $7700.00 | Window Closed / Lapsed |