Silicon Production Process
AssigneeCirculon Hungary Ltd.
InventorsLeonard Nanis, Shi Yuan, Matthew Sakae Forkin
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Abstract
An improved process for producing high purity silicon results from the reaction of sodium with pure silicon tetrafluoride gas, which produces sodium fluoride as a by-product. The silicon tetrafluoride gas is formed by decomposing sodium fluorosilicate. The sodium fluorosilicate is produced by precipitation when fluorosilicic acid (FSA) is reacted with the by-product sodium fluoride in closed loop process. Likewise, the fluorosilicic acid is preferably formed at high purity using a source material that consists essentially of silica by reacting the by-product sodium fluoride with an acid to create reactive fluoride ions.
Claims24
A process for synthesizing an alkali earth metal fluorosilicate salt (AEMFS), the process comprising the steps of:
- a) providing a source of silicon consisting essentially of silica,
- b) providing a source of fluoride ions,
- c) providing a source of alkali earth metal ions,
- d) reacting the source of silicon with the fluoride ions to form fluorosilicic acid (FSA), silicon tetrafluoride and the alkali earth metal fluorosilicate salt (AEMFS),
- e) separating at least the AEMFS from the reaction products.
A process for synthesizing silicon, the process comprising the steps of:
- a) providing a source of silicon consisting essentially of silica,
- b) providing a source of fluoride ions,
- c) providing a source of alkali earth metal ions,
- d) reacting the source of silicon with the fluoride ions to form fluorosilicic acid (FSA), silicon tetrafluoride and an alkali earth metal fluorosilicate salt (AEMFS),
- e) separating at least the AEMFS from the reaction products,
- f) decomposing the AEMFS to generate silicon tetrafluoride gas,
- g) reacting the silicon tetrafluoride gas with sodium to produce metallic silicon and the alkali earth metal salt of fluorine.
A process for synthesizing silicon, the process comprising the steps of:
- a) providing a source of silicon consisting essentially of silica,
- b) providing a source of fluoride ions,
- c) providing a source of sodium ions,
- d) reacting the source of silicon with the fluoride ions to form fluorosilicic acid (FSA), silicon tetrafluoride and sodium fluorosilicate (SFS).
- e) separating at least the SFS from the reaction products,
- f) decomposing the SFS to generate silicon tetrafluoride gas,
- g) reacting the silicon tetrafluoride gas with sodium to produce metallic silicon and sodium fluoride.
Dependencies are inferred from the claim text.