Patent US3625842A successfully refreshed from Google Patents.
US3625842A
Expired / Lapsed
US
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Alumina feed control
Assignee: Kaiser Aluminum and Chemical Corp
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Filing: 1968-05-24
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Granted: 1971-12-07
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Expires: 1988-05-24
Abstract
Abstract A method of controlling the feeding of alumina to a reduction cell for the production of aluminum. The method comprises obtaining several measurements of the voltage across the cell and current to the cell and deriving from the measurements an average resistance level for the cell which will be referred to as a base level. A smoothed resistance is derived from several sequential measurements of the voltage and current. When the smoothed resistance exceeds the base resistance level by more than an assigned limit, a controlled amount of alumina is added to the cell.
Inventors
- 👤 Donald R Bristol
- 👤 Joseph G C Simard
- 👤 J G Clement Simard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:27
CPC Classifications
C; C25; C25C; C25C3/00; C25C3/06; C25C3/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
19 words
The method of claim 1 wherein said first interval of time is greater than said second interval of time.
Claim 2
Dependent Claim
25 words
The method of claim 1 including the step of adjusting the distance between the anode and cathode following the addition of alumina to the cell.
References Cited (Backward Citations)
US1837070A
Cited
US3294656A
Cited
US3434945A
Cited
US3455795A
Cited
US3380897A
Cited
US3573179A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |