Claims
- 1. An electric shaft furnace, particularly for manufacturing high-purity silicon from silicon dioxide by carbothermic reduction comprising:
- a reaction chamber having sidewalls, at least a bottom of the chamber having a thermal insulating lining, the thermal insulating lining being composed of an innermost layer and several additional different layers of high-purity carbon, the high-purity carbon layers being selected from the group consisting of graphite, graphite grit and carbon black/shoot; and
- said innermost layer of said thermal insulating lining defining a melting pot composed of graphite for receiving reactants in said reaction chamber.
- 2. The furnace of claim 1 wherein the high purity carbon has a boron content and phosphorous content each having a maximum of 0.05 ppmw and has an overall ash content of a maximum of 10 ppmw.
- 3. The furnace of claim 1 wherein the thermal insulating lining is present only in the bottom region of the reaction chamber, thereby rendering said sidewalls of the chamber and thereby excluding lining from the sidewalls of the reaction chamber coolable.
- 4. The furnace of claim 1 wherein the thermal insulating lining of the furnace has three layers that, from said innermost layer of the lining toward an outside layer of lining, are respectively constructed from graphite, graphite grits, and lampblack.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3732073 |
Sep 1987 |
DEX |
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Parent Case Info
This is a continuation of application Ser. No. 236,845, filed Aug. 26, 1988 now abandoned.
US Referenced Citations (7)
Foreign Referenced Citations (1)
Number |
Date |
Country |
3215081 |
Mar 1983 |
DEX |
Non-Patent Literature Citations (1)
Entry |
H. A. Aulich et al, Solar-Grade Silicon Prepared by Advanced Carbothermic Reduction of Silica, Siemens Forsch.--U. Entwickl.--Ber. Bd. 15 (1986), No. 4, Springer-Verlag, 1986, pp. 157-162. |
Continuations (1)
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Number |
Date |
Country |
Parent |
236845 |
Aug 1988 |
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