Patent US2939767A successfully refreshed from Google Patents.
US2939767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of iron oxides
Assignee: Columbian Carbon Co
•
Filing: 1957-10-07
•
Granted: 1960-06-07
•
Expires: 1977-10-07
Abstract
No abstract record available.
Inventors
- 👤 Martin John
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:32
CPC Classifications
C; C01; C01G; C01G49/00; C01G49/02; C01G49/06; C01P; C01P2006/00; C01P2006/60
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
123 words
IN THE PROCESS FOR PRECIPITATING PIGMENTARY ALPHA FERRIC OXIDE HYDRATE FROM AQUEOUS FERROUS SALT SOLUTION WHEREBY A FREE OXYGEN-CONTAINING GAS IN PASSED IN INTIMATE CONTACT WITH THE SALT SOLUTION, FERRIC OXIDE IS FORMED AND HYDROLYZED WITH EVOLUTION OF HYDROGEN IONS AND THE HYDROGEN IONS ARE NEUTRALIZED TO MAINTAIN THE PH OF THE SOLUTION WITHIN THE RANGE OF 2.5 TO 5, THE STEP OF MAINTAINING THE HYDROGEN ION CONCENTRATION WITHIN SAID RANGE BY INTRODUCING INTO THE AQUEOUS SALT SOLUTION ANHYDROUS AMMONIA PREMIXED WITH THE FREE OXYGEN-CONTAINING GAS, WHILE MAINTAINING THE TEMPERATURE OF THE SOLUTION WITHIN THE RANGE OF 125* TO 200*F., THE CONCENTRATION OF THE ANHYDROUS AMMONIA IN THE GAS MIXTURE BEING WITHIN THE RANGE EXTENDING FROM ABOUT 0.5% TO ABOUT 25% BY WEIGHT.
Claim 2
Dependent Claim
123 words
IN THE PROCESS FOR PRECIPITATING PIGMENTARY ALPHA FERRIC OXIDE HYDRATE FROM AQUEOUS FERROUS SALT SOLUTION WHEREBY A FREE OXYGEN-CONTAINING GAS IN PASSED IN INTIMATE CONTACT WITH THE SALT SOLUTION, FERRIC OXIDE IS FORMED AND HYDROLYZED WITH EVOLUTION OF HYDROGEN IONS AND THE HYDROGEN IONS ARE NEUTRALIZED TO MAINTAIN THE PH OF THE SOLUTION WITHIN THE RANGE OF 2.5 TO 5, THE STEP OF MAINTAINING THE HYDROGEN ION CONCENTRATION WITHIN SAID RANGE BY INTRODUCING INTO THE AQUEOUS SALT SOLUTION ANHYDROUS AMMONIA PREMIXED WITH THE FREE OXYGEN-CONTAINING GAS, WHILE MAINTAINING THE TEMPERATURE OF THE SOLUTION WITHIN THE RANGE OF 125* TO 200*F., THE CONCENTRATION OF THE ANHYDROUS AMMONIA IN THE GAS MIXTURE BEING WITHIN THE RANGE EXTENDING FROM ABOUT 0.5% TO ABOUT 25% BY WEIGHT.
References Cited (Backward Citations)
GB190023858A
Cited
US1994702A
Cited
US2388659A
Cited
US2560970A
Cited
US2529874A
Cited
US2605169A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-06-07 | 1963-12-07 | 1964-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-06-07 | 1967-12-07 | 1968-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-06-07 | 1971-12-07 | 1972-06-07 | $7700.00 | Window Closed / Lapsed |