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US3660025A
Expired / Lapsed
US
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Manufacture of pigmentary silica
Assignee: Cities Service Co
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Filing: 1970-07-01
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Granted: 1972-05-02
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Expires: 1990-07-01
Abstract
Abstract A mixture of fluid fuel and oxygen is burned at a substantially constant rate to produce hot flame gases. Silicon tetrafluoride is commingled with these hot gases and is thus hydrolyzed. The concentration of silicon tetrafluoride in the hydrolysis mixture is established at a selected value which corresponds in direct proportion to the surface area desired of the silica product, i.e., the surface area of the silica is increased by raising the concentration of silicon tetrafluoride in the hydrolysis mixture, and vice versa.
Inventors
- 👤 Richard E Driscoll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:01
CPC Classifications
B; B82; B82Y; B82Y30/00; C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/18; C01B33/181; C01B33/183; C01B33/184; C01P; C01P2004/00; C01P2004/60; C01P2004/64; C01P2006/00; C01P2006/12; C01P2006/13
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
19 words
The process of claim 1 wherein said additional oxygen is introduced into the mixture in the form of air.
Claim 2
Dependent Claim
21 words
The process of claim 1 wherein the silicon tetrafluoride is introduced into the hydrolysis chamber in mixture with a diluent vapor.
Claim 3
Dependent Claim
26 words
The process of claim 3 wherein the mol fraction of silicon tetrafluoride in the diluted mixture is within the range of about 0.02 to about 0.14.
Claim 4
Dependent Claim
23 words
The process of claim 3 wherein the diluent vapor is selected from the group consisting of water vapor, hydrogen fluoride, and mixtures thereof.
Claim 5
Dependent Claim
40 words
The process of claim 1 wherein the oxygen which is mixed with said fuel is supplied for mixture therewith in the form of a gas selected from the group consisting of substantially pure oxygen, air enriched with oxygen, and air.
Claim 6
Dependent Claim
14 words
The process of claim 1 wherein the fluid fuel is a normally gaseous fuel.
Claim 7
Dependent Claim
27 words
The process of claim 7 wherein the fluid is selected from the group consisting of carbon monoxide, hydrogen, methane, ethane, propane, butane, natural gas, and mixtures thereof.
Claim 8
Dependent Claim
40 words
The process of claim 1 wherein the fuel gas during step (a) is in excess with respect to the oxygen to the extent that the stoichiometric fraction, phi , is within the range of about 1.3 to about 1.8 where:
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) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |