US3851047A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for continuously processing waste nitric acid solutions
Assignee: Pall Filtration and Separations Group Inc
•
Filing: 1972-12-21
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Granted: 1974-11-26
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Expires: 1992-12-21
Abstract
Abstract 1. A METHOD FOR CONTINUOUSLY PROCESSING NITRIC ACID SOLUTIONS CONTAINING FERRIC NITRTE TO PRODUCE SUBSTANTIALLY PURE NITRIC ACID AND FERRIC OXIDE WHEREIN SUBSTANTIALLY NO INSOLUBLE NITROGEN OXIDE GASES ARE EVOLVED, COMPRISING: (A) FLASH EVAPORATING SAID SOLUTION AT ABOUT THE BOILING TEMPERATURE OF AN AXEOTROPIC MIXTURE OF NITRIC ACID AND WATER, 8B) RECOVERING SUBSTANTIALLY PURE NITRIC ACID AS THE OVERHEAD FROM SAID FLASH EVAPORATION, AND (C) SEPARATING FERRIC HYDROXIDE AND RECOVERING FERRIC OXIDE FROM THE BOTTOMS OF SAID FLASH EVAPORATION.
Inventors
- 👤 D Bailey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:36
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/20; C01B21/38; C01B21/42; C01G; C01G49/00; C01G49/02; C01G49/06; Y; Y10; Y10S; Y10S423/00; Y10S423/01
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
78 words
A METHOD FOR CONTINUOUSLY PROCESSING NITRIC ACID SOLUTIONS CONTAINING FERRIC NITRTE TO PRODUCE SUBSTANTIALLY PURE NITRIC ACID AND FERRIC OXIDE WHEREIN SUBSTANTIALLY NO INSOLUBLE NITROGEN OXIDE GASES ARE EVOLVED, COMPRISING: (A) FLASH EVAPORATING SAID SOLUTION AT ABOUT THE BOILING TEMPERATURE OF AN AXEOTROPIC MIXTURE OF NITRIC ACID AND WATER, 8B) RECOVERING SUBSTANTIALLY PURE NITRIC ACID AS THE OVERHEAD FROM SAID FLASH EVAPORATION, AND (C) SEPARATING FERRIC HYDROXIDE AND RECOVERING FERRIC OXIDE FROM THE BOTTOMS OF SAID FLASH EVAPORATION.
Claim 2
Independent Claim
78 words
A METHOD FOR CONTINUOUSLY PROCESSING NITRIC ACID SOLUTIONS CONTAINING FERRIC NITRTE TO PRODUCE SUBSTANTIALLY PURE NITRIC ACID AND FERRIC OXIDE WHEREIN SUBSTANTIALLY NO INSOLUBLE NITROGEN OXIDE GASES ARE EVOLVED, COMPRISING: (A) FLASH EVAPORATING SAID SOLUTION AT ABOUT THE BOILING TEMPERATURE OF AN AXEOTROPIC MIXTURE OF NITRIC ACID AND WATER, 8B) RECOVERING SUBSTANTIALLY PURE NITRIC ACID AS THE OVERHEAD FROM SAID FLASH EVAPORATION, AND (C) SEPARATING FERRIC HYDROXIDE AND RECOVERING FERRIC OXIDE FROM THE BOTTOMS OF SAID FLASH EVAPORATION.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |