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Title: Process and apparatus for obtaining silicon from fluosilicic acid

Abstract

Process for producing low cost, high purity solar grade Si wherein a reduction reaction, preferably the reduction of SiF.sub.4, by an alkali metal (liquid Na preferred) is carried out essentialy continuously by injecting of reactants in substantially stoichiometric proportions into a reaction chamber having a controlled temperature thereby to form a mist or dispersion of reactants. The reactants being supplied at such a rate and temperature that the reaction takes place far enough away from the entry region to avoid plugging of reactants at the entry region, the reaction is completed and whereby essentially all reaction product solidifies and forms a free flowing powder before reaction product hits a reaction chamber wall. Thus, the reaction product does not adhere to the reaction chamber wall or pick up impurities therefrom. Separation of reaction products is easily carried out by either a leach or melt separation process.

Inventors:
 [1]
  1. Menlo Park, CA
Issue Date:
OSTI Identifier:
865515
Patent Number(s):
4529576
Application Number:
06/453,457
Assignee:
SRI International (Menlo Park, CA)
Patent Classifications (CPCs):
B - PERFORMING OPERATIONS B01 - PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL B01J - CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY
C - CHEMISTRY C01 - INORGANIC CHEMISTRY C01B - NON-METALLIC ELEMENTS
DOE Contract Number:  
954471-NAS 7-100
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
process; apparatus; obtaining; silicon; fluosilicic; acid; producing; cost; purity; solar; grade; reduction; reaction; preferably; sif; alkali; metal; liquid; na; preferred; carried; essentialy; continuously; injecting; reactants; substantially; stoichiometric; proportions; chamber; controlled; temperature; form; mist; dispersion; supplied; rate; takes; entry; region; avoid; plugging; completed; whereby; essentially; product; solidifies; forms; free; flowing; powder; hits; wall; adhere; pick; impurities; therefrom; separation; products; easily; leach; melt; reaction takes; na preferred; fluosilicic acid; controlled temperature; free flowing; separation process; reaction chamber; alkali metal; reaction product; reaction products; chamber wall; solar grade; purity solar; entry region; obtaining silicon; reduction reaction; melt separation; free flow; avoid plugging; impurities therefrom; silicic acid; liquid na; /423/136/422/

Citation Formats

Sancier, Kenneth M. Process and apparatus for obtaining silicon from fluosilicic acid. United States: N. p., 1985. Web.
Sancier, Kenneth M. Process and apparatus for obtaining silicon from fluosilicic acid. United States.
Sancier, Kenneth M. Tue . "Process and apparatus for obtaining silicon from fluosilicic acid". United States. https://www.osti.gov/servlets/purl/865515.
@article{osti_865515,
title = {Process and apparatus for obtaining silicon from fluosilicic acid},
author = {Sancier, Kenneth M},
abstractNote = {Process for producing low cost, high purity solar grade Si wherein a reduction reaction, preferably the reduction of SiF.sub.4, by an alkali metal (liquid Na preferred) is carried out essentialy continuously by injecting of reactants in substantially stoichiometric proportions into a reaction chamber having a controlled temperature thereby to form a mist or dispersion of reactants. The reactants being supplied at such a rate and temperature that the reaction takes place far enough away from the entry region to avoid plugging of reactants at the entry region, the reaction is completed and whereby essentially all reaction product solidifies and forms a free flowing powder before reaction product hits a reaction chamber wall. Thus, the reaction product does not adhere to the reaction chamber wall or pick up impurities therefrom. Separation of reaction products is easily carried out by either a leach or melt separation process.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jul 16 00:00:00 EDT 1985},
month = {Tue Jul 16 00:00:00 EDT 1985}
}