US3201199A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing low soda content alumina
Assignee: Alcan Research and Development Ltd
•
Filing: 1962-03-06
•
Granted: 1965-08-17
•
Expires: 1982-03-06
Abstract
No abstract record available.
Inventors
- 👤 Lindsay James Gordon
- 👤 Kinsman William Peter Charles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:14
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/04; C01F7/14; C01F7/144; C01F7/46
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
163 words
A METHOD OF PREPARING LOW SODA CONTENT ALUMINA TRIHYDRATE WHICH COMPRISES FORMING A SOLUTION OF ALUMINA IN AQUEOUS CAUSTIC AT AN ELEVATED TEMPERATURE AND EFFECTING PRECIPITATION OF ALUMINA TRIHYDRATE, SUBSTANTIALLY FREE OF SODA, FROM SAID SOLUTION AT A TEMPERATURE LOWER THAN SAID ELEVATED TEMPERATURE AND IN THE PRESENCE OF ADDED SOLID ALUMINA TRIHYDRATE, SAID SOLUTION AT SAID LOWER TEMPERATURE BEING SUPERSATURATED WITH ALUMINA TRIHYDRATE, SAID LOWER TEMPERATURE BEING MAINTAINED DURING THE PRECIPITATION OF ALUMINA TRIHYDRATE SUCH THAT THE AMOUNT OF ALUMINA SUPERSATURATION DURING THE PRECIPITATION IS NOT GREATER THAN 0.13 RATIO UNIT ABOVE THE EQUILIBRIUM SOLUBILITY OF THE ALUMINA TRIHYDRATE IN THE AQUEOUS CAUSTIC SOLUTION FROM WHICH THE ALUMINA TRIHYDRATE IS PRECIPITATED, SAID RATIO UNIT BEING DEFINED AS THE ALUMINA/CAUSTIC RATIO WHEREIN ALUMINA IS EXPRESSED IN TERMS OF GRAMS PER LITER AL2O3 AND CAUSTIC IS EXPRESSED IN TERMS OF GRAMS PER LITER EQUIVALENT NA2CO3, AND RECOVERING AS PRODUCT THE RESULTING PRECIPITATED, SUBSTANTIALLY SODA FREE, ALUMINA TRIHYDRATE HAVING A SODA CONTENT BELOW ABOUT 0.10%.
Claim 2
Independent Claim
163 words
A METHOD OF PREPARING LOW SODA CONTENT ALUMINA TRIHYDRATE WHICH COMPRISES FORMING A SOLUTION OF ALUMINA IN AQUEOUS CAUSTIC AT AN ELEVATED TEMPERATURE AND EFFECTING PRECIPITATION OF ALUMINA TRIHYDRATE, SUBSTANTIALLY FREE OF SODA, FROM SAID SOLUTION AT A TEMPERATURE LOWER THAN SAID ELEVATED TEMPERATURE AND IN THE PRESENCE OF ADDED SOLID ALUMINA TRIHYDRATE, SAID SOLUTION AT SAID LOWER TEMPERATURE BEING SUPERSATURATED WITH ALUMINA TRIHYDRATE, SAID LOWER TEMPERATURE BEING MAINTAINED DURING THE PRECIPITATION OF ALUMINA TRIHYDRATE SUCH THAT THE AMOUNT OF ALUMINA SUPERSATURATION DURING THE PRECIPITATION IS NOT GREATER THAN 0.13 RATIO UNIT ABOVE THE EQUILIBRIUM SOLUBILITY OF THE ALUMINA TRIHYDRATE IN THE AQUEOUS CAUSTIC SOLUTION FROM WHICH THE ALUMINA TRIHYDRATE IS PRECIPITATED, SAID RATIO UNIT BEING DEFINED AS THE ALUMINA/CAUSTIC RATIO WHEREIN ALUMINA IS EXPRESSED IN TERMS OF GRAMS PER LITER AL2O3 AND CAUSTIC IS EXPRESSED IN TERMS OF GRAMS PER LITER EQUIVALENT NA2CO3, AND RECOVERING AS PRODUCT THE RESULTING PRECIPITATED, SUBSTANTIALLY SODA FREE, ALUMINA TRIHYDRATE HAVING A SODA CONTENT BELOW ABOUT 0.10%.
References Cited (Backward Citations)
US1943786A
Cited
US2352867A
Cited
US2657978A
Cited
US2559653A
Cited
US2707669A
Cited
US2935376A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-08-16 | 1969-02-15 | 1969-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-08-16 | 1973-02-15 | 1973-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-08-16 | 1977-02-15 | 1977-08-17 | $7700.00 | Window Closed / Lapsed |