US3573179A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for the control of electrolytic refining cells
Assignee: International Business Machines Corp
•
Filing: 1965-12-14
•
Granted: 1971-03-30
•
Expires: 1985-12-14
Abstract
Abstract METHOD AND SYSTEM FOR CONTROLLING THE ADDITION OF ALUMINA TO ELECTROLYTIC ALUMINUM REFINING CELLS TO AVOID THE OCCURRENCE OF "ANODE EFFECTS" THEREIN. CONTROL OF INDIVIDUAL REFINING CELLS IS BASED UPON THE SLOPE OR TREND OF THE BATH RESISTANCE PROFILE INSTEAD OF ACTUAL MEASURED RESISTANCE VALUES. THE BATH RESISTANCE VALUES ARE ACCU- MULATED OVER A PERIOD OF TIME AND THE AVERAGE RATE OF CHANGE OR TREND OF THE RESISTANCE CURVE DERTERMINED. WHEN THE SLOPE OR TREND REACHES A PREDETERMINED VALUE, THE REQUIREMENT FOR ADDITION OF ALUMINA TO THE BATH IS INDICATED.
Inventors
- 👤 George P Dirth
- 👤 Terrence K Mcmahon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:55
CPC Classifications
C; C25; C25C; C25C3/00; C25C3/06; C25C3/20
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-29 | 1974-09-28 | 1975-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-29 | 1978-09-28 | 1979-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-29 | 1982-09-28 | 1983-03-30 | $7700.00 | Window Closed / Lapsed |