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:
Jun. 01, 2010
Filed:
Mar. 13, 2008
Dominic Leblanc, Bécancour, CA;
René Boisvert, Trois-Riviéres, CA;
Dominic Leblanc, Bécancour, CA;
René Boisvert, Trois-Riviéres, CA;
Silicum Becancour Inc., Becancour, Quebec, CA;
Abstract
A process for purifying low-purity metallurgical grade silicon, contains at least one contaminant and obtains a higher-purity solid polycrystalline silicon. The process includes containing a melt of low-purity metallurgical grade silicon in a mold having insulated bottom and side walls, and an open top; solidifying the melt by unidirectional solidification from the open top towards the bottom wall while electromagnetically stirring the melt; controlling a rate of the unidirectional solidification; stopping the unidirectional solidification when the melt has partially solidified to produce an ingot having an exterior shell including the higher-purity solid polycrystalline silicon and a center including an impurity-enriched liquid silicon; and creating an opening in the exterior shell of the ingot to outflow the impurity-enriched liquid silicon and leave the exterior shell which has the higher-purity solid polycrystalline silicon.