US3887359A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reduction of silicon dioxide by means of carbon in electric furnace
Assignee: Elkem ASA
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Filing: 1973-01-16
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Granted: 1975-06-03
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Expires: 1993-01-16
Abstract
Abstract Silicon and silicon-containing alloys are produced in an electric furnace by reduction of silicon oxide with carbon wherein reaction gases pass through a portion of the charge rich in carbon to enhance furnace operation. According to the present invention, at least a major amount of the reaction materials of silicon dioxide and carbon are separated from each other in the furnace and as a result the reaction gases will pass through a portion of the charge rich in carbon which tends to react with the silicon and silicon oxide gas and hold these materials in the furnace. Better control of the course of reaction is achieved and inexpensive raw materials may be utilized in the process.
Inventors
- 👤 Rolf Enger
- 👤 Kristian Piene
- 👤 Nils Skreien
- 👤 Audun Saethre
- 👤 Jan-Erik Thorslund
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:53
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/02; C01B33/021; C01B33/023; C01B33/025
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
122 words
In the method of producing silicon and silicon-containing alloy products in an electric furnace which involves the reduction of SiO2 with carbon reducing reagent by energy supplied by one or more electrodes in the furnace, the improvement which comprises the steps of feeding at least a major amount of the reaction SiO2 material in the charge into the furnace separate from the carbon reducing reagent in the charge and establishing at least two separate zones in the furnace one of which has a major amount of SiO2 material and the other of which has a major amount of carbon reducing reagent and wherein reaction off gases from the reduction of SiO2 pass through one or more zones rich in carbon reducing agent.
Claim 2
Dependent Claim
122 words
In the method of producing silicon and silicon-containing alloy products in an electric furnace which involves the reduction of SiO2 with carbon reducing reagent by energy supplied by one or more electrodes in the furnace, the improvement which comprises the steps of feeding at least a major amount of the reaction SiO2 material in the charge into the furnace separate from the carbon reducing reagent in the charge and establishing at least two separate zones in the furnace one of which has a major amount of SiO2 material and the other of which has a major amount of carbon reducing reagent and wherein reaction off gases from the reduction of SiO2 pass through one or more zones rich in carbon reducing agent.
Claim 3
Dependent Claim
122 words
IN THE METHOD OF PRODUCING SILICON AND SILICON-CONTAINING ALLOY PRODUCTS IN AN ELECTRIC FURNACE WHICH INVOLVES THE REDUCTION OF SIO2 WITH CARBON REDUCING REAGENT BY ENERGY SUPPLIED BY ONE OR MORE ELECTRODES IN THE FURNACE, THE IMPROVEMENT WHICH COMPRISES THE STEPS OF FEEDING AT LEAST A MAJOR AMOUNT OF THE REACTION SIO2 MATERIAL IN THE CHARGE INTO THE FURNACE SEPARATE FROM THE CARBON REDUCING REAGENT IN THE CHARGE AND ESTABLISHING AT LEAST TWO SEPARATE ZONES IN THE FURNACE ONE OF WHICH HAS A MAJOR AMOUNT OF SIO2 MATERIAL AND THE OTHER OF WHICH HAS A MAJOR AMOUNT OF CARBON REDUCING REAGENT AND WHEREIN REACTION OFF GASES FROM THE REDUCTION OF SIO2 PASS THROUGH ONE OR MORE ZONES RICH IN CARBON REDUCING AGENT.
Claim 4
Dependent Claim
122 words
IN THE METHOD OF PRODUCING SILICON AND SILICON-CONTAINING ALLOY PRODUCTS IN AN ELECTRIC FURNACE WHICH INVOLVES THE REDUCTION OF SIO2 WITH CARBON REDUCING REAGENT BY ENERGY SUPPLIED BY ONE OR MORE ELECTRODES IN THE FURNACE, THE IMPROVEMENT WHICH COMPRISES THE STEPS OF FEEDING AT LEAST A MAJOR AMOUNT OF THE REACTION SIO2 MATERIAL IN THE CHARGE INTO THE FURNACE SEPARATE FROM THE CARBON REDUCING REAGENT IN THE CHARGE AND ESTABLISHING AT LEAST TWO SEPARATE ZONES IN THE FURNACE ONE OF WHICH HAS A MAJOR AMOUNT OF SIO2 MATERIAL AND THE OTHER OF WHICH HAS A MAJOR AMOUNT OF CARBON REDUCING REAGENT AND WHEREIN REACTION OFF GASES FROM THE REDUCTION OF SIO2 PASS THROUGH ONE OR MORE ZONES RICH IN CARBON REDUCING AGENT.
Claim 5
Dependent Claim
20 words
The method specified in claim 1 which includes the step of removing product from the lower part of the furnace.
Claim 6
Dependent Claim
23 words
The method specified in claim 1 which includes the step of feeding other metal oxides into the furnace along with the SiO2 material.
Claim 7
Dependent Claim
20 words
The method specified in claim 1 which includes the step of feeding quartz into the furnace as the SiO2 material.
Claim 8
Dependent Claim
45 words
The method specified in claim 1 which includes the step of feeding quartz sand into the furnace as the SiO2 material to establish poor gas permeability and cause the majority of thE furnace reaction gases to flow up through a zone rich in reducing agent.
Claim 9
Dependent Claim
24 words
The method specified in claim 1 which includes the step of feeding the SiO2 material directly into the energy rich zone of the furnace.
Claim 10
Dependent Claim
26 words
The method specified in claim 1 which includes the step of establishing circular zones of SiO2 material and circular zones of reducing reagent surrounding the electrode.
Claim 11
Dependent Claim
29 words
The method specified in claim 1 which includes the step of establishing sectors rich in SiO2 material and separate sectors rich in reducing reagent around one or more electrodes.
Claim 12
Dependent Claim
31 words
The method specified in claim 1 which includes the step of feeding the SiO2 material at a controlled rate corresponding to the rate at which energy is supplied to the furnace.
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) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |