The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 06, 2012
Filed:
May. 25, 2007
Kunio Saegusa, Tsukubamirai, JP;
Tetsuo Oishi, Tsukuba, JP;
Kazuya Koyama, Tsukuba, JP;
Sumitomo Chemical Company, Limited, Tokyo, JP;
National Institute of Advanced Industrial Science and Technology, Tokyo, JP;
Abstract
Disclosed is a novel method for producing high-purity silicon at low cost. Particularly disclosed is a novel method for producing high-purity silicon, which can be suitably used as a raw material for solar cells, at low cost. Specifically, a method for producing silicon wherein silica is subjected to molten salt electrolysis in an electrolysis vessel comprises, in the following order, a step (1) wherein the silicon content in an silicon-containing alloy, which is in a liquid phase at the electrolysis temperature, is increased by using the alloy as the cathode and performing electrolysis; a step (2) wherein the silicon-containing alloy serving as the cathode is taken out of the electrolysis vessel before it reaches the concentration at which silicon begins to precipitate at the electrolysis temperature; a step (3) wherein silicon is solidified by cooling the taken-out silicon-containing alloy within the temperature range higher than the eutectic point but lower than the electrolysis temperature; and a step (4) wherein the solidified silicon is collected.