US3231331A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical process for the production of phosphoric acid
Assignee: Fisons Fertilizers Ltd
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Filing: 1961-11-13
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Granted: 1966-01-25
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Expires: 1981-11-13
Abstract
No abstract record available.
Inventors
- 👤 Robinson Norman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:33
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
141 words
A CONTINUOUS PROCESS FOR THE MANUFACTURE OF PHOSPHORIC ACID BY THE REACTION OF PHOSPHATE ROCK AND SULPHURIC ACID AND RECYCLED PHOSPHORIC ACID IN A SERIES OF 2 TO 20 VESSELS WHICH COMPRISES ADDING THE PHOSPHATE ROCK TO THE FIRST VESSEL IN THE SERIES, AGITATING THE CONTENTS OF THE FIRST VESSEL, CIRCULATING THE REACTION MIXTURE, WHICH COMPRISES GYPSUM AND PHOSPHORIC ACID, WITH AGITATION THROUGH THE SUBSEQUENT VESSELS IN THE SERIES, WITHDRAWING PART OF THE REACTION MIXTURE FOR SEPARATION OF PHOSPHORIC ACID FROM THE LAST VESSEL IN THE SERIES, AND WITHDRAWING ANOTHER PART OF SAID REACTION MIXTURE AND ADDING SULFURIC ACID THERETO AND RECIRCULATIN SAME FROM THE LAST VESSEL IN THE SERIES TO THE FIRST VESSEL IN THE SERIES, THE HOLDING TIME IN SAID FIRST VESSEL BEING ABOUT 1.5 TO 5 TIMES GREATER THAN THE HOLDING TIME IN ANY OF THE OTHER VESSELS.
Claim 2
Dependent Claim
141 words
A CONTINUOUS PROCESS FOR THE MANUFACTURE OF PHOSPHORIC ACID BY THE REACTION OF PHOSPHATE ROCK AND SULPHURIC ACID AND RECYCLED PHOSPHORIC ACID IN A SERIES OF 2 TO 20 VESSELS WHICH COMPRISES ADDING THE PHOSPHATE ROCK TO THE FIRST VESSEL IN THE SERIES, AGITATING THE CONTENTS OF THE FIRST VESSEL, CIRCULATING THE REACTION MIXTURE, WHICH COMPRISES GYPSUM AND PHOSPHORIC ACID, WITH AGITATION THROUGH THE SUBSEQUENT VESSELS IN THE SERIES, WITHDRAWING PART OF THE REACTION MIXTURE FOR SEPARATION OF PHOSPHORIC ACID FROM THE LAST VESSEL IN THE SERIES, AND WITHDRAWING ANOTHER PART OF SAID REACTION MIXTURE AND ADDING SULFURIC ACID THERETO AND RECIRCULATIN SAME FROM THE LAST VESSEL IN THE SERIES TO THE FIRST VESSEL IN THE SERIES, THE HOLDING TIME IN SAID FIRST VESSEL BEING ABOUT 1.5 TO 5 TIMES GREATER THAN THE HOLDING TIME IN ANY OF THE OTHER VESSELS.
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) | 1969-01-24 | 1969-07-26 | 1970-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-24 | 1973-07-26 | 1974-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-24 | 1977-07-26 | 1978-01-25 | $7700.00 | Window Closed / Lapsed |