Method for processing silicon powder to obtain silicon crystals
Assignee6N Silicon Inc.
InventorScott Nichol
Life of this patent
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Abstract
Embodiments of the present invention relate to a process for obtaining silicon crystals from silicon. The method includes contacting silicon powder with a solvent metal to provide a mixture containing silicon, melting the silicon under submersion 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 to form first silicon crystals and a first mother liquid and separating the first silicon crystals and the first mother liquid.
Claims19
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.
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;
- 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;
- separating the first silicon crystals and the first mother liquid;
- and
- washing the first silicon crystals with acid.
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;
- to provide a first molten liquid;
- contacting the first molten liquid with an initial gas;
- 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.
Dependencies are inferred from the claim text.