METHOD FOR PURIFYING SILICON

摘要

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.

主权项

1. 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; and, (g) separating the second silicon crystals and the second mother liquor.