US5009703A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon smelting process in direct current furnace
Assignee: Dow Silicones Corp
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Filing: 1990-08-13
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Granted: 1991-04-23
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Expires: 2010-08-13
Abstract
Abstract The instant invention is a process for preparing silicon metal in a direct current, submerged-arc furnace. The process comprises adding a source of silicon dioxide and a source of carbon to a substantially closed furnace. Heat is provided to the furnace by striking a direct current arc between a moveable cathode and a anode functional hearth. Silicon metal is tapped from the furnace. The described process may also be used to prepare silicon metal alloys.
Inventors
- 👤 Arvid N. Arvidson
- 👤 Vishu D. Dosaj
- 👤 James B. May
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:50
CPC Classifications
C; C22; C22B; C22B4/00; C01; C01B; C01B33/00; C01B33/02; C01B33/021; C01B33/023; C01B33/025
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
52 words
A process for preparation of elemental silicon, the process comprising: (A) adding a feed mixture comprising a source of silicon dioxide and a source of carbon to a substantially closed furnace: (B) heating the substantially closed furnace with a direct current, submerged-arc; and (C) tapping elemental silicon from the substantially closed furnace.
Claim 2
Dependent Claim
52 words
A process for preparation of elemental silicon, the process comprising: (A) adding a feed mixture comprising a source of silicon dioxide and a source of carbon to a substantially closed furnace: (B) heating the substantially closed furnace with a direct current, submerged-arc; and (C) tapping elemental silicon from the substantially closed furnace.
Claim 3
Dependent Claim
27 words
A process according to claim 1, where the feed mixture has a molar ratio of fixed carbon to silicon dioxide in a range of 1.5 to 2.5.
Claim 4
Dependent Claim
25 words
A process according to claim 1, where the feed mixture has a molar ratio of fixed carbon to silicon dioxide of about 1.8 to 2.0.
Claim 5
Dependent Claim
28 words
A process according to claim 1, where the direct current, submerged-arc is struck between a graphite cathode electrode and an anode functional hearth of the substantially closed furnace.
Claim 6
Dependent Claim
23 words
A process according to claim 4, where a silicon carbide layer is interposed between the graphite cathode electrode and the anode functional hearth.
Claim 7
Dependent Claim
18 words
A process according to claim 1, where the substantially closed furnace has at least one side wall vent.
Claim 8
Dependent Claim
16 words
A process according to claim 6, where by-product gases are collected from the side wall vent.
Claim 9
Dependent Claim
13 words
A process according to claim 7, where the by-product gas comprises carbon monoxide.
Claim 10
Dependent Claim
17 words
A process according to claim 8, where the by-product carbon monoxide is used as a chemical feedstock.
Claim 11
Dependent Claim
15 words
A process according to claim 8, where the carbon monoxide is used as a fuel.
Claim 12
Dependent Claim
23 words
A process according to claim 1, where the substantially closed furnace has an internal height to diameter ratio of about 0.8 to 1.2.
Claim 13
Dependent Claim
21 words
A process according to claim 11, where the internal diameter is (100 to 150 in)×(power to furnace (KW)/6000 KW) 1/3 .
Claim 14
Dependent Claim
17 words
A process according to claim 4, where the substantially closed furnace has a plurality of graphite electrodes.
Claim 15
Dependent Claim
15 words
A process according to claim 5, where the silicon carbide layer is formed in situ.
Claim 16
Dependent Claim
20 words
A process according to claim 1, further comprising alloying the formed silicon metal with at least one other elemental metal.
References Cited (Backward Citations)
US3215522A
Cited
US4865643A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-04-22 | 1994-10-22 | 1995-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-22 | 1998-10-22 | 1999-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-22 | 2002-10-22 | 2003-04-23 | $7700.00 | Window Closed / Lapsed |