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US 7,883,680 B2Granted
Method for purifying silicon
Assignee6N Silicon Inc.
InventorScott Nichol
Life of this patent
Estimating the term…
Abstract
The present invention provides for methods of purifying silicon, methods for obtaining purified silicon, as well as methods for obtaining purified silicon crystals, purified granulized silicon and/or purified silicon ingots.
Claims20
A method for purifying silicon to solar-grade purity, the method comprising:
- (a) forming a first molten liquid from silicon and a solvent metal selected from the group of copper, tin, zinc, antimony, silver, bismuth, aluminum, cadmium, gallium, indium, magnesium, lead, an alloy thereof, and combinations thereof;
- (b) contacting the first molten liquid with a first gas, to provide a second molten liquid;
- (c) cooling the second molten liquid to form first silicon crystals and a first mother liquid;
- (d) separating the first silicon crystals and the first mother liquid;
- (e) heating the first silicon crystals to form a first molten bath;
- (f) directionally solidifying the first molten bath to form second silicon crystals and a second mother liquor;
- (g) separating the second silicon crystals and the second mother liquor;
- (h) heating the second silicon crystals to provide a second molten bath;
- (i) directionally solidifying the second molten bath below the melting point, thereby forming a third silicon crystals, and separating the upper portion and the lower portion;
- wherein the upper portion comprises a third mother liquor and the lower portion comprises a third silicon.
7 more elements
A method for purifying silicon to solar-grade purity, the method comprising:
- (a) forming a first molten liquid from silicon and a solvent metal selected from the group of copper, tin, zinc, antimony, silver, bismuth, aluminum, cadmium, gallium, indium, magnesium, lead, an alloy thereof, and combinations thereof;
- (b) contacting the first molten liquid with a first gas, to provide a second molten liquid;
- (c) cooling the second molten liquid to form first silicon crystals and a first mother liquid;
- (d) separating the first silicon crystals and the first mother liquid;
- (e) heating the first silicon crystals to form a first molten bath;
- (f) directionally solidifying the first molten bath to form second silicon crystals and a second mother liquor;
- (g) separating the second silicon crystals and the second mother liquor;
- (h) heating the second silicon crystals to provide a second molten bath;
- (i) contacting the second molten bath with a second gas to provide a slag that forms on the surface of a third molten bath;
- and,
- (j) separating the slag and the third molten bath.
8 more elements
Dependencies are inferred from the claim text.