US4040981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing denitrating catalysts
Assignee: Kanadevia Corp
•
Filing: 1976-06-24
•
Granted: 1977-08-09
•
Expires: 1996-06-24
Abstract
Abstract A denitrating catalyst is produced by plating the surface of unactivated metal with aluminum and immersing the resulting layered product in an aqueous aluminum-dissolving solution to dissolve out the aluminum into the aqueous solution and to thereby activate the surface of the metal.
Inventors
- 👤 Hideya Inaba
- 👤 Masayoshi Ichiki
- 👤 Yoshinori Wakiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:30
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/02; B01J37/0215; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9413; B01D53/9418; B01J25/00; B01J35/00; B01J35/30; B01J35/391; B01J35/395; B01D2251/00; B01D2251/20; B01D2251/206; B01D2251/2062; B01D2255/00; B01D2255/20; B01D2255/207; B01D2255/20738; B01D2255/20753; B01D2255/90; B01D2255/902; B01D2255/9027; B01J2235/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
92 words
A process for producing a denitrating catalyst comprising the steps of plating the surface of unactivated metal with aluminum to form a first layer containing the metal diffused in the aluminum and a second layer containing the aluminum diffused in the metal, immersing the resulting layered product in an aqueous aluminum-dissolving solution to dissolve out the aluminum into the aqueous solution, and contacting the metal from which all or part of the aluminum is dissolved out with a gas containing sulfurous acid gas to thereby activate the surface of the unactivated metal.
Claim 2
Dependent Claim
92 words
A process for producing a denitrating catalyst comprising the steps of plating the surface of unactivated metal with aluminum to form a first layer containing the metal diffused in the aluminum and a second layer containing the aluminum diffused in the metal, immersing the resulting layered product in an aqueous aluminum-dissolving solution to dissolve out the aluminum into the aqueous solution, and contacting the metal from which all or part of the aluminum is dissolved out with a gas containing sulfurous acid gas to thereby activate the surface of the unactivated metal.
Claim 3
Dependent Claim
27 words
A process as defined in claim 1 wherein the unactivated metal is a metal selected from the group consisting of pure iron, stainless steel and nickel-base alloys.
Claim 4
Dependent Claim
17 words
A process as defined in claim 1 wherein the aqueous aluminum-dissolving solution is an aqueous acid solution.
Claim 5
Dependent Claim
34 words
A process as defined in claim 3 wherein the aqueous acid solution is an aqueous solution of an acid selected from the group consisting of hydrochloric acid, nitric acid, acetic acid and formic acid.
Claim 6
Dependent Claim
17 words
A process as defined in claim 1 wherein the aqueous aluminum-dissolving solution is an aqueous alkali solution.
Claim 7
Dependent Claim
18 words
A process as defined in claim 5 wherein the aqueous alkali solution is an aqueous solution of hydroxide.
Claim 8
Dependent Claim
13 words
A process as defined in claim 6 wherein the hydroxide is sodium hydroxide.
Claim 9
Dependent Claim
48 words
A process as defined in claim 1 wherein the layered product resulting from the aluminum plating step and including said first and second layers is heat-treated at a temperature of not lower than the melting point of aluminum to increase the thicknesses of the first and second layers.
Claim 10
Dependent Claim
18 words
A process as defined in claim 8 wherein the second layer has a thickness of at least 30μ.
Claim 11
Dependent Claim
21 words
A process as defined in claim 1 wherein at least 50% of the aluminum in the second layer is dissolved out.
Claim 12
Dependent Claim
20 words
A process as defined in claim 1 wherein the concentration of the sulfurous acid gas is at least 100 ppm.
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) | 1980-08-08 | 1981-02-07 | 1981-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-08 | 1985-02-07 | 1985-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-08 | 1989-02-07 | 1989-08-09 | $7700.00 | Window Closed / Lapsed |