Patent ID: 7959730
Filing Date: 2011-06-14
Classification: C01B,C30B,Y10T

Abstract:
1. A process for obtaining silicon crystals from silicon powder, comprising: contacting silicon powder with a solvent metal, to provide a mixture containing silicon; melting the silicon under submersion by feeding the silicon powder into a vortex within the solvent metal using a rotary degasser, rotary furnace, molten metal pump or induction currents, to provide a first molten liquid; contacting the first molten liquid with a first gas, to provide dross and a second molten liquid; separating the dross and the second molten liquid; cooling the second molten liquid approximately homogenously to provide fractional crystallization to form first silicon crystals and a first mother liquid; and separating the first silicon crystals and the first mother liquid; wherein the silicon that is obtained from the last step of the process is used to make solar cells.