Patent US2591436A successfully refreshed from Google Patents.
US2591436A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of alumina values
Assignee: Alcan Research and Development Ltd
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Filing: 1947-03-10
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Granted: 1952-04-01
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Expires: 1967-03-10
Abstract
No abstract record available.
Inventors
- 👤 James William Addison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:33
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/04; C01F7/06; C01F7/0673
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
64 words
IN A PROCESS OF SEPARATING ALUMINA VALUES FROM BAUXITE BY DIGESTION WITH CAUSTIC LIQUOR, WHEREIN THE BAUXITE CONTAINS MORE THAN 0.6% BY WEIGHT OF PHOSPHORUS PENTOXIDE WHICH IS CAPABLE OF CONTAMINATING THE LIQUOR, THE METHOD OF IMPEDING SOLUTION OF PHOSPHORUS IN SAID LIQUOR WHICH COMPRISES INTRODUCING CALCIUM CARBONATE AS SUCH INTO THE LIQUOR AND EFFECTING SAID DIGESTION IN THE PRESENCE OF SAID CALCIUM CARBONATE.
Claim 2
Dependent Claim
64 words
IN A PROCESS OF SEPARATING ALUMINA VALUES FROM BAUXITE BY DIGESTION WITH CAUSTIC LIQUOR, WHEREIN THE BAUXITE CONTAINS MORE THAN 0.6% BY WEIGHT OF PHOSPHORUS PENTOXIDE WHICH IS CAPABLE OF CONTAMINATING THE LIQUOR, THE METHOD OF IMPEDING SOLUTION OF PHOSPHORUS IN SAID LIQUOR WHICH COMPRISES INTRODUCING CALCIUM CARBONATE AS SUCH INTO THE LIQUOR AND EFFECTING SAID DIGESTION IN THE PRESENCE OF SAID CALCIUM CARBONATE.
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) | 1955-04-01 | 1955-10-01 | 1956-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-04-01 | 1959-10-01 | 1960-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-04-01 | 1963-10-01 | 1964-04-01 | $7700.00 | Window Closed / Lapsed |