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US 7,727,503 B2Granted
Method for purifying silicon
Assignee6N Silicon Inc.
InventorScott Nichol
Life of this patent
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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.
Claims23
A method for purifying silicon, 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 dross and a second molten liquid and a vortex of the first molten liquid is created, and the vortex is contacted with oxygen (O2) to provide additional dross;
- (c) separating the dross and the second molten liquid;
- (d) cooling the second molten liquid to form first silicon crystals and a first mother liquid;
- and
- (e) separating the first silicon crystals and the first mother liquid.
3 more elements
A method for purifying silicon, 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 and dross;
- (c) heating the second molten liquid;
- (d) separating the dross and the second molten liquid;
- (e) cooling the second molten liquid to form first silicon crystals and a first mother liquid;
- (f) separating the first silicon crystals and the first mother liquid;
- (g) heating the first silicon crystals to form a first molten bath;
- (h) directionally solidifying the first molten bath to form second silicon crystals and a second mother liquor;
- (i) heating the second silicon crystals to provide a second molten bath;
- (j) contacting the second molten bath with a second gas to form a slag that forms on the surface of a third molten bath;
- (k) separating the slag and the third molten bath;
- and at least one of steps (l)-(o):
- (l) cooling the second molten bath to form silicon ingots;
- (m) contacting the second molten bath with water to form granulized silicon;
- (n) introducing the third molten bath into a mold and cooling the third molten bath to form a second silicon;
- and
- (o) directionally solidifying the third 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.
15 more elements
Dependencies are inferred from the claim text.