Patent US2958575A successfully refreshed from Google Patents.
US2958575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of aluminum fluoride
Assignee: Dow Chemical Co
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Filing: 1958-04-21
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Granted: 1960-11-01
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Expires: 1978-04-21
Abstract
No abstract record available.
Inventors
- 👤 Donald R Allen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:56
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/48; C01F7/50
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
175 words
A COMTINUOUS PROCESS FOR THE PREPARATION OF ALUMINUM FLUORIDE, WHICH COMPRISES CONTINUOUSLY CHARGING AN AQUEOUS HYDROFLUORIC ACID SOLUTION CONTAINING FROM 40 TO 60 WEIGHT PERCENT OF THE ACID INTO A REACTOR HAVING A RETENTION TIME OF FROM 30 SECONDS TO 5 MINUTES, CONTINUOUSLY INTRODUCING AN ALUMINUM HYDROZIDE SLURRY INTO THE REACTOR, INTERMIXING THE SLURRY WITH THE HYDROFLUORIC ACID THEREIN SO AS TO REACT THE ALUMINUM FLUORIDE, SAID THE HYDROFLUORIC ACID TO FORM ALUMINUM FLUORIDE, SAID SLURRY BEING OBTAINED BY MIXING ALUMINUM HYDROZIDE WITH WATER AND THE MOTHER LIQUOR OBTAINED FROM THE LAST STEP OF THE PROCESS IN PROPORTIONS SUCH THAT THE TOTAL WATER IN THE SLURRY IS SUFFICIENT TO DILUTE THE HYDROFLUORIC ACID TO A CONCENTRATION OF FROM 13 TO 17 WEIGHT PERCENT, CONTINUALLY DISCHARGING THE REACTED MIXTURE OF ALUMINUM HYDROXIDE AND HYDROFLUORIC ACID FROM THE REACTOR INTO A CRYSTALLIZER, HEATING THE REACTED MIXTURE IN THE CRYSTALLIZER TO A TEMPERATURE BETWEEN 80*C. AND THE BOILING POINT FOR FROM 15 TO 30 MINUTES SO AS TO CRYSTALLIZE OUT ALUMINUM FLUORIDE, SEPARATING THE CRYSTALS OF ALUMINUM FLUORIDE
Claim 2
Dependent Claim
175 words
A COMTINUOUS PROCESS FOR THE PREPARATION OF ALUMINUM FLUORIDE, WHICH COMPRISES CONTINUOUSLY CHARGING AN AQUEOUS HYDROFLUORIC ACID SOLUTION CONTAINING FROM 40 TO 60 WEIGHT PERCENT OF THE ACID INTO A REACTOR HAVING A RETENTION TIME OF FROM 30 SECONDS TO 5 MINUTES, CONTINUOUSLY INTRODUCING AN ALUMINUM HYDROZIDE SLURRY INTO THE REACTOR, INTERMIXING THE SLURRY WITH THE HYDROFLUORIC ACID THEREIN SO AS TO REACT THE ALUMINUM FLUORIDE, SAID THE HYDROFLUORIC ACID TO FORM ALUMINUM FLUORIDE, SAID SLURRY BEING OBTAINED BY MIXING ALUMINUM HYDROZIDE WITH WATER AND THE MOTHER LIQUOR OBTAINED FROM THE LAST STEP OF THE PROCESS IN PROPORTIONS SUCH THAT THE TOTAL WATER IN THE SLURRY IS SUFFICIENT TO DILUTE THE HYDROFLUORIC ACID TO A CONCENTRATION OF FROM 13 TO 17 WEIGHT PERCENT, CONTINUALLY DISCHARGING THE REACTED MIXTURE OF ALUMINUM HYDROXIDE AND HYDROFLUORIC ACID FROM THE REACTOR INTO A CRYSTALLIZER, HEATING THE REACTED MIXTURE IN THE CRYSTALLIZER TO A TEMPERATURE BETWEEN 80*C. AND THE BOILING POINT FOR FROM 15 TO 30 MINUTES SO AS TO CRYSTALLIZE OUT ALUMINUM FLUORIDE, SEPARATING THE CRYSTALS OF ALUMINUM FLUORIDE
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) | 1963-11-01 | 1964-05-02 | 1964-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-11-01 | 1968-05-02 | 1968-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-11-01 | 1972-05-02 | 1972-11-01 | $7700.00 | Window Closed / Lapsed |