Patent US2921838A successfully refreshed from Google Patents.
US2921838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of preparing chromic oxide
Assignee: LEONARD J BUCK Inc
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Filing: 1957-04-23
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Granted: 1960-01-19
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Expires: 1977-04-23
Abstract
No abstract record available.
Inventors
- 👤 Francis L Melvill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:06
CPC Classifications
C; C01; C01G; C01G37/00; C01G37/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
158 words
THE PROCESS OF PREPARING CHROMIC OXIDE (CR2O3) FROM A STARTING MATERIAL SELECTED FROM THE GROUP CONSISTING OF ALKALI CHROMATES AND BICHROMATES, COMPRISING THE STEPS OF MIXING SAID STARTING MATERIAL WITH AN ALUMINUM COMPOUND, WHICH IS AT LEAST ONE OF THE MATERIALS SELECTED FROM THE GROUP CONSISTING OF AL2O3, AL(OH)8 AND ALOP4, THE AMOUNT OF SAID ALUMINUM COMPOUND BEING APPROXIMATELY STIOCHIOMETRICALLY EQUIVALENT TO THE AMOUNT OF ALKALI METAL INITIALLY PRESENT IN COMBINATION WITH SAID CHROMATES AND BICHROMATES TO FORM ALKALI ALUMINATE, HEATING THE MATERIALS SO MIXED IN THE PRESENCE OF A REDUCING AGENT AND TO A TEMPERATURE IN THE RANGE OF ABOUT 100*F. TO ABOUT 1200*F. SO AS TO INITIATE AN EXOTHERMIC REACTION THEREBETWEEN, AFTER THE COMPLETION OF SAID REACTION, LEACHING THE REACTION PRODUCTS WITH AN AQUEOUS SOLUTION OF CAUSTIC ALKALI IN SUFFICIENT AMOUNT AND CONCENTRATION TO DISSOLVE ALL THE ALUMINUM COMPOUNDS PRESENT AND TO LEAVE CHROMIC OXIDE UNDISSOLVED, AND SEPARATING THE LEACH SOLUTION FROM SAID UNDISSOLVED CHROMIC OXIDE.
Claim 2
Dependent Claim
158 words
THE PROCESS OF PREPARING CHROMIC OXIDE (CR2O3) FROM A STARTING MATERIAL SELECTED FROM THE GROUP CONSISTING OF ALKALI CHROMATES AND BICHROMATES, COMPRISING THE STEPS OF MIXING SAID STARTING MATERIAL WITH AN ALUMINUM COMPOUND, WHICH IS AT LEAST ONE OF THE MATERIALS SELECTED FROM THE GROUP CONSISTING OF AL2O3, AL(OH)8 AND ALOP4, THE AMOUNT OF SAID ALUMINUM COMPOUND BEING APPROXIMATELY STIOCHIOMETRICALLY EQUIVALENT TO THE AMOUNT OF ALKALI METAL INITIALLY PRESENT IN COMBINATION WITH SAID CHROMATES AND BICHROMATES TO FORM ALKALI ALUMINATE, HEATING THE MATERIALS SO MIXED IN THE PRESENCE OF A REDUCING AGENT AND TO A TEMPERATURE IN THE RANGE OF ABOUT 100*F. TO ABOUT 1200*F. SO AS TO INITIATE AN EXOTHERMIC REACTION THEREBETWEEN, AFTER THE COMPLETION OF SAID REACTION, LEACHING THE REACTION PRODUCTS WITH AN AQUEOUS SOLUTION OF CAUSTIC ALKALI IN SUFFICIENT AMOUNT AND CONCENTRATION TO DISSOLVE ALL THE ALUMINUM COMPOUNDS PRESENT AND TO LEAVE CHROMIC OXIDE UNDISSOLVED, AND SEPARATING THE LEACH SOLUTION FROM SAID UNDISSOLVED CHROMIC OXIDE.
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) | 1963-01-18 | 1963-07-20 | 1964-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-18 | 1967-07-20 | 1968-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-18 | 1971-07-20 | 1972-01-19 | $7700.00 | Window Closed / Lapsed |