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Title: Purified silicon production system

Abstract

Method and apparatus for producing purified bulk silicon from highly impure metallurgical-grade silicon source material at atmospheric pressure. Method involves: (1) initially reacting iodine and metallurgical-grade silicon to create silicon tetraiodide and impurity iodide byproducts in a cold-wall reactor chamber; (2) isolating silicon tetraiodide from the impurity iodide byproducts and purifying it by distillation in a distillation chamber; and (3) transferring the purified silicon tetraiodide back to the cold-wall reactor chamber, reacting it with additional iodine and metallurgical-grade silicon to produce silicon diiodide and depositing the silicon diiodide onto a substrate within the cold-wall reactor chamber. The two chambers are at atmospheric pressure and the system is open to allow the introduction of additional source material and to remove and replace finished substrates.

Inventors:
;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1174788
Patent Number(s):
6,712,908
Application Number:
10/243,503
Assignee:
Midwest Research Institute (Kansas City, MO) OSTI
DOE Contract Number:
AC36-99GO10337
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Wang, Tihu, and Ciszek, Theodore F. Purified silicon production system. United States: N. p., 2004. Web.
Wang, Tihu, & Ciszek, Theodore F. Purified silicon production system. United States.
Wang, Tihu, and Ciszek, Theodore F. Tue . "Purified silicon production system". United States. doi:. https://www.osti.gov/servlets/purl/1174788.
@article{osti_1174788,
title = {Purified silicon production system},
author = {Wang, Tihu and Ciszek, Theodore F.},
abstractNote = {Method and apparatus for producing purified bulk silicon from highly impure metallurgical-grade silicon source material at atmospheric pressure. Method involves: (1) initially reacting iodine and metallurgical-grade silicon to create silicon tetraiodide and impurity iodide byproducts in a cold-wall reactor chamber; (2) isolating silicon tetraiodide from the impurity iodide byproducts and purifying it by distillation in a distillation chamber; and (3) transferring the purified silicon tetraiodide back to the cold-wall reactor chamber, reacting it with additional iodine and metallurgical-grade silicon to produce silicon diiodide and depositing the silicon diiodide onto a substrate within the cold-wall reactor chamber. The two chambers are at atmospheric pressure and the system is open to allow the introduction of additional source material and to remove and replace finished substrates.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Mar 30 00:00:00 EST 2004},
month = {Tue Mar 30 00:00:00 EST 2004}
}

Patent:

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  • A continuous process is claimed for simultaneously producing a stream of cleaned purified synthesis gas having a mole ratio H/sub 2//CO in the range of about 2 to 12, and a separate stream of CO-rich gas. In one embodiment of the process, cleaned and purified methanol synthesis gas and substantially pure carbon monoxide are produced. Methanol may be synthesized and optionally catalytically reacted with the substantially pure carbon monoxide to produce acetic acid. In the subject process, the effluent gas stream directly from a free-flow unpacked noncatalytic partial-oxidation synthesis gas generator is split into two streams which are simultaneously processedmore » in two separate trains. In the first train, one of the split streams is cooled by indirect heat exchange in a gas cooler and then further processed to produce a stream of cleaned and purified synthesis gas, a H/sub 2/-rich gas stream, and the product stream of CO-rich gas and preferably substantially pure CO. Simultaneously, the second split stream in the second train is cooled by direct quenching in water in a quench drum, cleaned, subjected to catalytic water-gas-shift reaction, and purified to produce a second H/sub 2/-rich gas stream. The product stream of cleaned and purified synthesis gas having a mole ratio H/sub 2//CO in the range of about 2 to 12 is then produced by mixing together at least a portion of the cleaned and purified synthesis gas stream from the first train with 0 to 100 volume % of the H/sub 2/-rich gas stream from the first train and at least a portion of the H/sub 2/-rich gas stream from the second train.« less
  • A method is described for purifying metallic alloys of uranium for use as nuclear reactor fuels in which the metal alloy is first converted to an oxide and then dissolved in nitric acid. Initial removal of metal oxide impurities not soluble in nitric acid is accomplished by filtration or other physical means. Further purification can be accomplished by carbonate leaching of uranyl ions from the partially purified solution or using traditional methods such as solvent extraction. 3 figs.
  • A method for purifying metallic alloys of uranium for use as nuclear reactor fuels in which the metal alloy is first converted to an oxide and then dissolved in nitric acid. Initial removal of metal oxide impurities not soluble in nitric acid is accomplished by filtration or other physical means. Further purification can be accomplished by carbonate leaching of uranyl ions from the partially purified solution or using traditional methods such as solvent extraction.
  • A pyrometallurgical method for processing nuclear reactor fuel elements containing uranium and fission products and for reducing uranium compound; to metallic uranium is reported. If the material proccssed is essentially metallic uranium, it is dissolved in zinc, the sulution is cooled to crystallize UZn/sub 9/ , and the UZn/sub 9/ is distilled to obtain uranium free of fission products. If the material processed is a uranium compound, the sollvent is an alloy of zinc and magnesium and the remaining steps are the same.