US3664870A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal and separation of metallic oxide scale
Assignee: ChampionX LLC
•
Filing: 1969-10-29
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Granted: 1972-05-23
•
Expires: 1989-10-29
Abstract
Abstract A method of removing metallic oxide scale from the cooling system of a nuclear reactor is disclosed. By forming complexes of the metals using ammoniated citric acid, the scale can be removed. By selectively adsorbing these complexes on ion exchange resins the scale can be separated.
Inventors
- 👤 Alfred W Oberhofer
- 👤 Donald R Anderson
- 👤 Charles C Payne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:10
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/02; C23G1/08; C23G1/088; C23G1/36
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
18 words
The method of claim 1 in which the scale is the crud from a nuclear reactor cooling system.
Claim 2
Dependent Claim
43 words
The method of claim 2 in which an oxidant selected from the group consisting of sodium nitrate, ammonium persulfate, ammonium perborate, and hydrogen peroxide is added after the pH is adjusted to from 9-11 with ammonia to enhance the dissolution of the copper.
Claim 3
Dependent Claim
31 words
The method of claim 3 including the additional step of: regenerating the ion exchange resins using a compound selected from the group consisting of mineral acids, and salts of mineral acids.
Claim 4
Dependent Claim
20 words
The method of claim 4 including the additional step of: treating the anion exchange resin with sodium hydroxide after regeneration.
References Cited (Backward Citations)
US3033214A
Cited
US3013909A
Cited
US3072502A
Cited
US3116240A
Cited
US3340200A
Cited
US3496017A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |