Patent US3339559A successfully refreshed from Google Patents.
US3391996A
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Phosphoric acid process
Assignee: Pullman Inc
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Filing: 1965-05-07
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Granted: 1968-07-09
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Expires: 1985-05-07
Abstract
No abstract record available.
Inventors
- 👤 Christiaan P Van Dijk
- 👤 James P Van Hook
- 👤 Kenneth M Barclay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:52
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
A PROCESS FOR THE PRODUCTION AND CONCENTATION OF PHOSPHORIC ACID: CONTACTING AN AQUEOUS SOLUTION CONTAINING PHOSPHORIC ACID AND GASEOUS PRODUCTS OF COMBUSTION OBTAINED AT AN ELEVATED TEMPERATURE BY OXIDATION OF A SULFUR-CONTAINING MATERIAL IN AN OXYGEN-CONTAINING GAS TO PRODUCE SULFUR DIOXIDE THEREBY TRANSFERRING WATER FROM THUS-CONCENTRATED PHOSPHORIC ACID INTO A WET GASEOUS MIXTURE CONTAINING SULFUR DIOXIDE, CATALYTICALLY OXIDIZING SAID WET GASEOUS MIXTURE TO OBTAIN AQUEOUS SULFURIC ACID, EMPLOYING SAID AQUEOUS SULFURIC ACID FOR THE DIGESTION OF PHOSPHATIC MATERIAL TO OBTAIN PHOSPHORIC ACID AND HYDRATED CALCIUM SULFATE, SEPARATING SUCH CALCIUM SULFATE FROM SAID ACID AND THEN CONTACTING SAID ACID AND GASEOUS COMBUSTION PRODUCTS AS DEFINED ABOVE TO OBTAIN CONCENTRATED PHOSPHORIC ACID.
Claim 2
Dependent Claim
110 words
A PROCESS FOR THE PRODUCTION AND CONCENTATION OF PHOSPHORIC ACID: CONTACTING AN AQUEOUS SOLUTION CONTAINING PHOSPHORIC ACID AND GASEOUS PRODUCTS OF COMBUSTION OBTAINED AT AN ELEVATED TEMPERATURE BY OXIDATION OF A SULFUR-CONTAINING MATERIAL IN AN OXYGEN-CONTAINING GAS TO PRODUCE SULFUR DIOXIDE THEREBY TRANSFERRING WATER FROM THUS-CONCENTRATED PHOSPHORIC ACID INTO A WET GASEOUS MIXTURE CONTAINING SULFUR DIOXIDE, CATALYTICALLY OXIDIZING SAID WET GASEOUS MIXTURE TO OBTAIN AQUEOUS SULFURIC ACID, EMPLOYING SAID AQUEOUS SULFURIC ACID FOR THE DIGESTION OF PHOSPHATIC MATERIAL TO OBTAIN PHOSPHORIC ACID AND HYDRATED CALCIUM SULFATE, SEPARATING SUCH CALCIUM SULFATE FROM SAID ACID AND THEN CONTACTING SAID ACID AND GASEOUS COMBUSTION PRODUCTS AS DEFINED ABOVE TO OBTAIN CONCENTRATED PHOSPHORIC ACID.
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) | 1971-07-09 | 1972-01-08 | 1972-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-07-09 | 1976-01-08 | 1976-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-07-09 | 1980-01-08 | 1980-07-09 | $7700.00 | Window Closed / Lapsed |