US4307242A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for removing impurities from residual silicon powder
Assignee: General Electric Co
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Filing: 1980-11-24
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Granted: 1981-12-22
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Expires: 2000-11-24
Abstract
Abstract A process for recovering and recycling elementary silicon from a direct process organohalosilane reactor system is provided, comprising the steps of analyzing a portion of effluent contact mass, such as the silicon fines from a secondary cyclone with a particle size distribution analyzer, determing the fines fractions containing the relatively greatest amounts of impurities and segregating a relatively impure fine fraction from a purer coarse fraction with the aid of an aerodynamic centrifugal classifier.
Inventors
- 👤 Bakulesh N. Shah
- 👤 Alan Ritzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:25
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/08; C01B33/107; C01B33/1071; C07; C07F; C07F7/00; C07F7/02; C07F7/08; C07F7/12; C07F7/16
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
57 words
A process for purifying silicon metal contact mass from a direct process organohalosilane reactor system comprising the steps of: (a) analyzing a portion of reactor contact mass for particle size distribution; (b) classifying said analyzed contact mass into a relatively pure first fraction and a relatively impure second fraction; and (c) segregating said first and second fractions.
Claim 2
Dependent Claim
57 words
A process for purifying silicon metal contact mass from a direct process organohalosilane reactor system comprising the steps of: (a) analyzing a portion of reactor contact mass for particle size distribution; (b) classifying said analyzed contact mass into a relatively pure first fraction and a relatively impure second fraction; and (c) segregating said first and second fractions.
Claim 3
Dependent Claim
25 words
A process as in claim 1, further comprising the step of recycling said relatively pure first fraction to the same or a different organohalosilane reactor.
Claim 4
Dependent Claim
21 words
A process as in claims 1 or 2 wherein said organohalosilane reactor system is comprised of one or more methylchlorosilane reactors.
Claim 5
Dependent Claim
62 words
A process as in claim 1 wherein said first and second fractions are classified by selecting a fraction cut point such that substantially all silicon particles in said relatively pure first fraction have a diameter size greater than said cut point and substantially all silicon particles in said relatively impure second fraction have a diameter size less than said fraction cut point.
Claim 6
Dependent Claim
30 words
A process as in claim 1 further comprising the step of chemically analyzing said portion of reactor contact mass to determine the relative purity of each particle size distributed fraction.
Claim 7
Dependent Claim
40 words
A process as in claim 4 wherein said fraction cut point selection is accomplished by preselecting the weight percent of contact mass, based upon the total of said reactor contact mass, which shall reside in said relatively pure first fraction.
Claim 8
Dependent Claim
18 words
A process as in claim 1 wherein said segregating step is accomplished by a centrifugal and aerodynamic classifier.
Claim 9
Dependent Claim
18 words
A process as in claim 1 wherein said fraction cut is made at, approximately, 3 to 20 microns.
Claim 10
Dependent Claim
16 words
A process as in claim 1 wherein said reactor contact mass is secondary cyclone silicon fines.
Claim 11
Dependent Claim
17 words
A process as in claim 1 wherein said reactor contact mass is direct process reactor bed powder.
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) | 1984-12-21 | 1985-06-22 | 1985-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-21 | 1989-06-22 | 1989-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-21 | 1993-06-22 | 1993-12-22 | $7700.00 | Window Closed / Lapsed |