US3945865A
Expired / Lapsed
US
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Metal dissolution process
Assignee: Lancy International Inc
•
Filing: 1974-07-22
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Granted: 1976-03-23
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Expires: 1994-07-22
Abstract
Abstract Evolution of NOx fumes during dissolution of metal values in mineral acid solutions of nitric acid can be eliminated by the addition of small quantities of hydrogen peroxide to the acid solution.
Inventors
- 👤 David Robert Kamperman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:31
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/02; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F3/00; C23F3/04; C23F3/06
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
66 words
A method for prevention of evolution of NOx fumes in the dissolution of metal values in mineral acid solutions containing HNO 3 which comprises adding hydrogen peroxide to said acid solution, maintaining the hydrogen peroxide concentration during the dissolution at between about 1 and about 20 grams per liter and the mole ratio of hydrogen peroxide to mineral acid at a value of less than 0.273.
Claim 2
Independent Claim
66 words
A method for prevention of evolution of NOx fumes in the dissolution of metal values in mineral acid solutions containing HNO 3 which comprises adding hydrogen peroxide to said acid solution, maintaining the hydrogen peroxide concentration during the dissolution at between about 1 and about 20 grams per liter and the mole ratio of hydrogen peroxide to mineral acid at a value of less than 0.273.
Claim 3
Dependent Claim
23 words
The method of claim 1 in which the dissolution is carried out at temperatures in the range from about 10° to about 70°C.
Claim 4
Dependent Claim
16 words
A process of claim 2 in which said temperatures range from about 20° to about 55°C.
Claim 5
Dependent Claim
16 words
A process according to claim 1 wherein a hydrogen-peroxide stabilizer is added to the acid solution.
Claim 6
Dependent Claim
33 words
A process according to claim 4 wherein the hydrogen peroxide stabilizer is selected from fatty acids, glycerine, glycols, allyl alcohol, crotyl alcohol, cis-1,4-but-ene-diol, phenol, p-phenol sulfonic acid or salts thereof or p-methoxy phenol.
Claim 7
Dependent Claim
14 words
A process according to claim 4 wherein the hydrogen peroxide stabilizer is ethylene glycol.
Claim 8
Dependent Claim
31 words
A process according to claim 1 wherein the mineral acid solution is a mixture of nitric acid and at least one acid selected from sulfuric acid, hydrofluoric acid and hydrochloric acid.
Claim 9
Dependent Claim
80 words
A process for bright dipping copper or copper alloys without evolution of NOx fumes which comprises immersing the copper or copper alloy in a bright dip acid solution containing from about 430 to about 460 grams per liter of H 2 SO 4 , from about 100 to about 150 grams per liter of HNO 3 from about 0.2 to about 3 grams per liter of HCl and from about 8 to about 12 grams per liter of hydrogen peroxide.
Claim 10
Dependent Claim
80 words
A process for bright dipping copper or copper alloys without evolution of NOx fumes which comprises immersing the copper or copper alloy in a bright dip acid solution containing from about 430 to about 460 grams per liter of H 2 SO 4 , from about 100 to about 150 grams per liter of HNO 3 from about 0.2 to about 3 grams per liter of HCl and from about 8 to about 12 grams per liter of hydrogen peroxide.
Claim 11
Dependent Claim
15 words
The process of claim 8 wherein the acid solution also contains a hydrogen peroxide stabilizer.
Claim 12
Dependent Claim
15 words
The process of claim 8 wherein the acid solution also contains a surface passivation agent.
Claim 13
Dependent Claim
62 words
A bright dip solution for copper or copper alloys comprising: from about 430 to about 460 grams per liter of H 2 SO 4 ; from about 100 to about 150 grams per liter of HNO 3 ; from about 0.2 to about 3 grams per liter of HCl, and from about 8 to about 12 grams per liter of hydrogen peroxide.
Claim 14
Dependent Claim
62 words
A bright dip solution for copper or copper alloys comprising: from about 430 to about 460 grams per liter of H 2 SO 4 ; from about 100 to about 150 grams per liter of HNO 3 ; from about 0.2 to about 3 grams per liter of HCl, and from about 8 to about 12 grams per liter of hydrogen peroxide.
Claim 15
Dependent Claim
13 words
The bright dip solution of claim 11 also containing a hydrogen peroxide stabilizer.
Claim 16
Dependent Claim
13 words
The bright dip solution of claim 11 also containing a surface passivation agent.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |