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Patent US3294656A successfully refreshed from Google Patents.
US3294656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing aluminium
Assignee: Rio Tinto Switzerland AG
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Filing: 1962-10-16
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Granted: 1966-12-27
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Expires: 1982-10-16
Abstract
No abstract record available.
Inventors
- 👤 Schmitt Johannes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:33
CPC Classifications
C; C25; C25C; C25C3/00; C25C3/06; C25C3/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
132 words
THE METHOD OF OPERATING AN ELECTROLYTIC FURNACE EITHER WITH PREBAKED ANODES OR WITH SELFBAKING SODERBERG CARBON ANODES FOR THE PRODUCTION OF ALUMINUM BY PASSING DIRECT ELECTRIC CURRENT THROUGH A FLUORIDE ELECTROYTE COMPOSED MAINLY OF MOLTEN CRYOLITE 3NAF.ALF3 AND CONTAINING AN EXCESS OF ALUMINUM FLUORIDE ALF3 ABOVE THAT AMOUNT WHICH IS COMBINED IN THE CRYOLITE AS WELL AS DISSOLVED ALUMINA AL2O3, COMPRISING MAINTAINING DURING A PERIOD OF AT LEAST 12 HOURS AND AT MOST 48 HOURS THE ELECTROLYTE TEMPERATURE BETWEEN 940* AND 960*C., THE CONCENTRATION OF ALUMINA BETWEEN 5 AND 7% BY WEIGHT AND OF ALUMINUM FLUORIDE EXCESS BETWEEN 5 AND 7% BY WEIGHT, AND PREVENTING THE CONCENTRATION OF ALUMINA AND OF EXCESS ALUMINUM FLUORIDE FROM DROPPING BELOW 5% DURING SAID PERIOD BY FREQUENT ADDITIONS OF ALUMINA AND ALUMINUM FLUORIDE TO THE ELECTROLYTE.
Claim 2
Independent Claim
132 words
THE METHOD OF OPERATING AN ELECTROLYTIC FURNACE EITHER WITH PREBAKED ANODES OR WITH SELFBAKING SODERBERG CARBON ANODES FOR THE PRODUCTION OF ALUMINUM BY PASSING DIRECT ELECTRIC CURRENT THROUGH A FLUORIDE ELECTROYTE COMPOSED MAINLY OF MOLTEN CRYOLITE 3NAF.ALF3 AND CONTAINING AN EXCESS OF ALUMINUM FLUORIDE ALF3 ABOVE THAT AMOUNT WHICH IS COMBINED IN THE CRYOLITE AS WELL AS DISSOLVED ALUMINA AL2O3, COMPRISING MAINTAINING DURING A PERIOD OF AT LEAST 12 HOURS AND AT MOST 48 HOURS THE ELECTROLYTE TEMPERATURE BETWEEN 940* AND 960*C., THE CONCENTRATION OF ALUMINA BETWEEN 5 AND 7% BY WEIGHT AND OF ALUMINUM FLUORIDE EXCESS BETWEEN 5 AND 7% BY WEIGHT, AND PREVENTING THE CONCENTRATION OF ALUMINA AND OF EXCESS ALUMINUM FLUORIDE FROM DROPPING BELOW 5% DURING SAID PERIOD BY FREQUENT ADDITIONS OF ALUMINA AND ALUMINUM FLUORIDE TO THE ELECTROLYTE.
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) | 1969-12-26 | 1970-06-27 | 1970-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-12-26 | 1974-06-27 | 1974-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-12-26 | 1978-06-27 | 1978-12-27 | $7700.00 | Window Closed / Lapsed |