US3878291A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of metal free chlorosilane by the chlorination or hydrochlorination of ferrosilicon
Assignee: Evonik Operations GmbH
•
Filing: 1972-10-04
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Granted: 1975-04-15
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Expires: 1992-10-04
Abstract
Abstract Iron, aluminium and titanium free silicon tetrachloride or a mixture thereof with silicochloroform and/or dichlorosilane is prepared by the continuous reaction of lumpy ferrosilicon with chlorine or hydrogen chloride in a closed reactor which has a support for the ferrosilicon as well as means for supplying the halogenation agent in its lower portion and has a ferrosilicon supply and reaction gas exit in its upper portion. The temperature in the top space of the reactor is held below the sublimation temperature of ferric chloride by spraying in liquid chlorosilane and the reaction gas, in a given case by way of a cyclone, is supplied to a washer pressurized with liquid chlorosilane; the mixture of gas, liquid and solid leaving this washer is introduced directly into a separator for liquid and solid laden with liquid chlorosilane, the separated gas lead through a washing column pressurized with pure chlorosilane and finally pure chlorosilane is condensed out.
Inventors
- 👤 Rudolf Keller
- 👤 Hans Klebe
- 👤 Heinz-Rudiger Vollbrecht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:57
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/08; C01B33/04; C01B33/107
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
104 words
A PROCESS FOR THE PRODUCTION (1) SILICON TETRACHLORIDE, (2) A MIXTURE OF SILICON TETRACHLORIDE WITH A MINOR AMOUNT OF SILICOCHLOROFORM, OR (3) A MIXTURE OF SILICON TETRACHLORIDE WITH A MINOR AMOUNT OF BOTH SILICOCHLOROFORM AND DICHLOROSILANE FREE OF IRON, ALUMINUM AND TITANIUM WHICH COMPRISES REACTING LUMPY FERROSILICON WITH CHLORINE OR HYDROGEN CHLORIDE AS THE CHLORINATING AGENT IN A CLOSED REACTOR WHICH IN ITS LOWER PORTION HAS SUPPORT MEANS FOR THE FERROSILICON AND A CHLORINATING AGENT INLET AND ITS UPPER PORTION A FERROSILICON INLET AND A REACTION GAS OUTLET, HOLDING THE TEMPERATURE IN THE TOP SPACE OF THE REACTOR BELOW THE SUBLIMATION TEMPERATURE OF IRON
Claim 2
Dependent Claim
104 words
A PROCESS FOR THE PRODUCTION (1) SILICON TETRACHLORIDE, (2) A MIXTURE OF SILICON TETRACHLORIDE WITH A MINOR AMOUNT OF SILICOCHLOROFORM, OR (3) A MIXTURE OF SILICON TETRACHLORIDE WITH A MINOR AMOUNT OF BOTH SILICOCHLOROFORM AND DICHLOROSILANE FREE OF IRON, ALUMINUM AND TITANIUM WHICH COMPRISES REACTING LUMPY FERROSILICON WITH CHLORINE OR HYDROGEN CHLORIDE AS THE CHLORINATING AGENT IN A CLOSED REACTOR WHICH IN ITS LOWER PORTION HAS SUPPORT MEANS FOR THE FERROSILICON AND A CHLORINATING AGENT INLET AND ITS UPPER PORTION A FERROSILICON INLET AND A REACTION GAS OUTLET, HOLDING THE TEMPERATURE IN THE TOP SPACE OF THE REACTOR BELOW THE SUBLIMATION TEMPERATURE OF IRON
Claim 3
Dependent Claim
22 words
A process according to claim 1 wherein the reaction gases from the reactor are sent to a cyclone to remove solids therefrom.
Claim 4
Dependent Claim
27 words
A process according to claim 1 wherein the chlorosilane sprayed into the top space of the reactor is pure chlorosilane returned from another portion of the process.
Claim 5
Dependent Claim
22 words
A process according to claim 1 wherein the liquid chlorosilane is maintained at a constant level below the region of gas separation.
Claim 6
Dependent Claim
17 words
A process according to claim 1 wherein the washer is supplied with liquid chlorosilane from the separator.
Claim 7
Dependent Claim
16 words
A process according to claim 5 wherein the washing column is pressurized with recycled pure chlorosilane.
Claim 8
Dependent Claim
52 words
A process according to claim 1 wherein the separator has a sump and at intervals sediment is removed from the sump of the separator, chlorosilane and titanium IV chloride therein are driven out over a heated column filled with alkali halide and volatiles from said column are separated by a final distillation.
Claim 9
Dependent Claim
21 words
A process according to claim 7 wherein the alkali halide is alkali chloride, the column is heated to at least 180*C.
Claim 10
Dependent Claim
16 words
A process according to claim 8 wherein the volatiles are condensed prior to said final distillation.
Claim 11
Dependent Claim
40 words
A process according to claim 7 wherein the residue in the separator is treated with steam to hydrolyze the same and the hydrogen chloride set free is scrubbed with water in an absorption column to convert it to hydrochloric acid.
Claim 12
Dependent Claim
14 words
A process according to claim 10 wherein the hydrolysis residue is evaporated to dryness.
Claim 13
Dependent Claim
83 words
A process according to claim 7 wherein the sediment from the sump of the separator is passed to a heated, rotating paddle dryer provided with a sediment inlet, vapor supply line and fluid outlet, the chlorosilane and titanium IV chloride are expelled therefrom and sent to an alkali halide tower and then the residue in the dryer hydrolyzed with steam to produce hydrochloric acid, the hydrolysis residue dried, the direction of rotation of the dryer reversed and the residue discharged from the drier.
Claim 14
Dependent Claim
15 words
A process according to claim 1 wherein the lumpy ferrosilicon is reacted with hydrogen chloride.
Claim 15
Dependent Claim
14 words
A process according to claim 1 wherein the lumpy ferrosilicon is reacted with chlorine.
Claim 16
Dependent Claim
53 words
A process according to claim 1 wherein purified chlorosilane is (1) returned to the reactor to quench the temperature in the top space thereof, (2) is returned to a washing column for gases leaving the solids separator and (3) is returned to the reactor below the ferrosilicon together with chlorine or hydrochloric acid.
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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) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |