Patent US3899573A successfully refreshed from Google Patents.
US3899573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of fine powders
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1971-10-18
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Granted: 1975-08-12
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Expires: 1991-10-18
Abstract
Abstract An improvement in comminuting particulate inorganic oxides is achieved by vaporizing the oxides in an electric arc column in the presence of a reducing agent and thereafter contacting the vapors with an oxygen containing quench gas. The process is particularly useful in preparing submicron silica powder.
Inventors
- 👤 Henry Shaw
- 👤 Derek J Angier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:14
CPC Classifications
B; B01; B01J; B01J12/00; B01J12/002; B82; B82Y; B82Y30/00; C; C01; C01B; C01B13/00; C01B13/14; C01B13/145; C01B33/00; C01B33/113; C01B33/12; C01B33/18; C01B33/181; C01B33/182; C01F; C01F7/00; C01F7/02; C01F7/021; C01F7/027; H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/32; H05H1/34; H05H1/3452; C01P; C01P2004/00; C01P2004/60; C01P2004/62; C01P2004/64
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
129 words
IN THE PROCESS OF COMMINUTING A PARTICULATE INORGANIC OXIDE BY VAPORIZING THE INORGANIC OXIDE WITH A PLASMA JET AND SUBSEQUENTLY RECONDENSING THE VAPORIZED INORGANIC OXIDE, THE IMPROVEMENT COMPRISING: PROVIDING A FREE BURNING ARC DISCHARGE BETWEEN AN ANODE AND A CATHODE HAVING A CONICAL TIP WHEREBY SAID ARC DISCHARGE FORMS A CONTRACTION ZONE OF CURRENT-CARRYING AREA IN THE TRANSITION REGION IN THE VICINITY OD THE CATHODE, FORCEFULLY PROJECTING A PARTICULATE INORGANIC OXIDE ALONG SAID CONICAL TIP OF SAID CATHODE INTO AND THROUGH SAID CONTRACTION OF THE CURRENT-CARRYING AREA INTO SAID ARC DISCHARGE WHILE SIMULTANEOUSLY FORCEFULLY PROJECTING A REDUCING AGENT ALONG SAID CONICAL TIP OF SAID CATHODE INTO AND THROUGH SAID CONTRACTION OF THE CURRENT-CARRYING AREA INTO SAID ARC DISCHARGE, AND, THEREAFTER CONTACTING THE VAPORS WITH AN OXYGEN CONTAINING QUENCH GAS.
Claim 2
Dependent Claim
129 words
IN THE PROCESS OF COMMINUTING A PARTICULATE INORGANIC OXIDE BY VAPORIZING THE INORGANIC OXIDE WITH A PLASMA JET AND SUBSEQUENTLY RECONDENSING THE VAPORIZED INORGANIC OXIDE, THE IMPROVEMENT COMPRISING: PROVIDING A FREE BURNING ARC DISCHARGE BETWEEN AN ANODE AND A CATHODE HAVING A CONICAL TIP WHEREBY SAID ARC DISCHARGE FORMS A CONTRACTION ZONE OF CURRENT-CARRYING AREA IN THE TRANSITION REGION IN THE VICINITY OD THE CATHODE, FORCEFULLY PROJECTING A PARTICULATE INORGANIC OXIDE ALONG SAID CONICAL TIP OF SAID CATHODE INTO AND THROUGH SAID CONTRACTION OF THE CURRENT-CARRYING AREA INTO SAID ARC DISCHARGE WHILE SIMULTANEOUSLY FORCEFULLY PROJECTING A REDUCING AGENT ALONG SAID CONICAL TIP OF SAID CATHODE INTO AND THROUGH SAID CONTRACTION OF THE CURRENT-CARRYING AREA INTO SAID ARC DISCHARGE, AND, THEREAFTER CONTACTING THE VAPORS WITH AN OXYGEN CONTAINING QUENCH GAS.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the reducing is selected from the group consisting of hydrogen, aliphatic hydrocarbons and carbon.
Claim 4
Dependent Claim
11 words
A process of claim 1 wherein the oxygen-containing gas is air.
Claim 5
Dependent Claim
11 words
The process of claim 1 wherein the reducing agent is hydrogen.
Claim 6
Dependent Claim
13 words
The process of claim 1 wherein said particulate inorganic oxide feed is silica.
Claim 7
Dependent Claim
19 words
The process of claim 1 wherein said inorganic oxide is selected from oxides of silica, magnesia, zirconia and alumina.
Claim 8
Dependent Claim
17 words
The process of claim 1 wherein said particulate inorganic oxide has a particle size below 80 microns.
Claim 9
Dependent Claim
25 words
The process of claim 1 wherein said inorganic oxide is entrained in said reducing agent and forcefully projected along said conical tip of said cathode.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |