Patent US1035678A successfully refreshed from Google Patents.
Patent US2799560A successfully refreshed from Google Patents.
US2799560A
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Conversion of sulphur dioxide to sulphur trioxide
Assignee: Imperial Chemical Industries Ltd
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Filing: 1954-09-07
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Granted: 1957-07-16
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Expires: 1974-09-07
Abstract
No abstract record available.
Inventors
- 👤 Davies Phineas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:34
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/16; B01J23/20; B01J23/22; C; C01; C01B; C01B17/00; C01B17/69; C01B17/74; C01B17/76; C01B17/78; C01B17/79
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
103 words
A PROCESS FOR THE OXIDATION OF SULPHUR DIOXIDE TO SULPHUR TRIOXIDE WHICH COMPRISES CONTACTING SULPHUR DIOXIDE AND A GAS CONTAINING FREE OXYGEN WITH A CATALYST COMPRISING OXIDES OF VANADIUM, POTASSIUM AND SILICON AND PRODUCED BY ADDING POTASSIUM SILICATE SOLUTION TO DILUTE SULPHURIC ACID WHEREBY A SILICA SOL IS FORMED, MIXING THE SILICA SOL WITH A SOLUBLE VANADIUM COMPOUND, AND CO-PRECIPITATING SILICA AND AN INSOLUBLE VANADIUM COMPOUND BY THE ADDITION OF AMMONIUM HYDROXIDE, THE POTASSIUM: VANADIUM RATIO, EXPRESSED AS THE MOLAR RATIO K2O:V2O5, BEING FROM 4.5:1 TO 6.0:1, AND THE REACTION BEING INITIATED AT A TEMPERATURE WITHIN THE RANGE OF 380* TO 400* C.
Claim 2
Dependent Claim
103 words
A PROCESS FOR THE OXIDATION OF SULPHUR DIOXIDE TO SULPHUR TRIOXIDE WHICH COMPRISES CONTACTING SULPHUR DIOXIDE AND A GAS CONTAINING FREE OXYGEN WITH A CATALYST COMPRISING OXIDES OF VANADIUM, POTASSIUM AND SILICON AND PRODUCED BY ADDING POTASSIUM SILICATE SOLUTION TO DILUTE SULPHURIC ACID WHEREBY A SILICA SOL IS FORMED, MIXING THE SILICA SOL WITH A SOLUBLE VANADIUM COMPOUND, AND CO-PRECIPITATING SILICA AND AN INSOLUBLE VANADIUM COMPOUND BY THE ADDITION OF AMMONIUM HYDROXIDE, THE POTASSIUM: VANADIUM RATIO, EXPRESSED AS THE MOLAR RATIO K2O:V2O5, BEING FROM 4.5:1 TO 6.0:1, AND THE REACTION BEING INITIATED AT A TEMPERATURE WITHIN THE RANGE OF 380* TO 400* C.
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) | 1960-07-15 | 1961-01-14 | 1961-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-07-15 | 1965-01-14 | 1965-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-07-15 | 1969-01-14 | 1969-07-16 | $7700.00 | Window Closed / Lapsed |