US2871092A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Niobium-tantalum separation
Assignee: Individual
•
Filing: 1955-08-15
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Granted: 1959-01-27
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Expires: 1975-08-15
Abstract
No abstract record available.
Inventors
- 👤 Harley A Wilhelm
- 👤 Raymond A Foos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:55
CPC Classifications
C; C01; C01G; C01G35/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
162 words
A PROCESS OF SUBSTANTIALLY REDUCING THE CORROSIVE EFFECT OF HYDROFLUORIC ACID ON METAL AND GLASS EQUIPMENT USED IN THE SELECTIVE EXTRACTION OF TANTALUM VALUES FROM AN AQUEOUS HYDROFLUORIC ACID SOLUTION CONTAINING SAID TANTALUM VALUES TOGETHER WITH NIOBIUM VALUES BY CONTACTING SAID SOLUTION WITH AN ORGANIC SUBSTANTIALLY WATERUMMISIBLE SOLVENT SELECTED FROM THE GROUP CONSISTING OF CYCLOHEXANONE, ISOPHORONE, MESITYL OXIDE, METHYL ISOBUTLY KETONE, METHYL N-BEXYL CARBINOL, DIETHYL KETONE, TRIBUTYL PHOSPHATE, ETHYL ACETOACETATE, M-TOLUIDINE AND A MIXTURE OF DIETHYL KETONE PLUS PRIMARY ALKYL AMINES HAVING BRANCHES ALKYL CHAINS IN WHICH THE PRIMARY AMOINO NITROGEN IS DIRECTLY ATTACHED TO A TERIARY CARBON ATOM AND IN WHICH THE AMINES CONTAIN FROM 12 TO 24 CARBON ATOMS PER MOLECULE, SAID PROCESS COMPRISING THE STEP OF ADDING TO SAID HYDROFLUORIC ACID SOLUTION, PRIOR TO CONTACTING WITH THE SOLVENT, AN AMINES SELECTED FROM THE GROUP CONSISTING OF PHENYLETHYLETHANOLAMINE,M-TOLYLDIETHANOLAMINE, PHENYL DIETHANOLAMINE AND ANILINE IN A QUANTITY TO ADJUST THE PH VALUE OF SAID HYDROFLUORIC ACID SOLUTION TO BETWEEN 4 AND 6.
Claim 2
Dependent Claim
162 words
A PROCESS OF SUBSTANTIALLY REDUCING THE CORROSIVE EFFECT OF HYDROFLUORIC ACID ON METAL AND GLASS EQUIPMENT USED IN THE SELECTIVE EXTRACTION OF TANTALUM VALUES FROM AN AQUEOUS HYDROFLUORIC ACID SOLUTION CONTAINING SAID TANTALUM VALUES TOGETHER WITH NIOBIUM VALUES BY CONTACTING SAID SOLUTION WITH AN ORGANIC SUBSTANTIALLY WATERUMMISIBLE SOLVENT SELECTED FROM THE GROUP CONSISTING OF CYCLOHEXANONE, ISOPHORONE, MESITYL OXIDE, METHYL ISOBUTLY KETONE, METHYL N-BEXYL CARBINOL, DIETHYL KETONE, TRIBUTYL PHOSPHATE, ETHYL ACETOACETATE, M-TOLUIDINE AND A MIXTURE OF DIETHYL KETONE PLUS PRIMARY ALKYL AMINES HAVING BRANCHES ALKYL CHAINS IN WHICH THE PRIMARY AMOINO NITROGEN IS DIRECTLY ATTACHED TO A TERIARY CARBON ATOM AND IN WHICH THE AMINES CONTAIN FROM 12 TO 24 CARBON ATOMS PER MOLECULE, SAID PROCESS COMPRISING THE STEP OF ADDING TO SAID HYDROFLUORIC ACID SOLUTION, PRIOR TO CONTACTING WITH THE SOLVENT, AN AMINES SELECTED FROM THE GROUP CONSISTING OF PHENYLETHYLETHANOLAMINE,M-TOLYLDIETHANOLAMINE, PHENYL DIETHANOLAMINE AND ANILINE IN A QUANTITY TO ADJUST THE PH VALUE OF SAID HYDROFLUORIC ACID SOLUTION TO BETWEEN 4 AND 6.
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) | 1962-01-26 | 1962-07-28 | 1963-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-01-26 | 1966-07-28 | 1967-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-01-26 | 1970-07-28 | 1971-01-27 | $7700.00 | Window Closed / Lapsed |