Method for silicon purification

A method of removing impurities from low grade silicon, comprising:

• mixing a solid-phase particulate zirconium compound with the solid-phase particulate low grade silicon to make a zirconium compound and silicon mixture;
• oxidizing one portion of the silicon in said mixture to form solid slag for adsorbing the impurities in a remaining generally unoxidized portion of the silicon;
• and
• melting the generally unoxidized portion of the silicon to allow zirconium and impurities in the generally unoxidized portion to migrate toward and become adsorbed by the slag.

A method of purifying low grade silicon having impurities, comprising the steps of:

• mixing the low grade silicon with zirconia to form a low grade silicon and zirconia mixture;
• forming pellets from the low grade silicon and zirconia mixture;
• oxidizing the outer surface of the pellets to form slag for adsorbing zirconia and the impurities from the remaining generally unoxidized low grade silicon and zirconia mixture;
• melting the remaining generally unoxidized low grade silicon and zirconia mixture to allow zirconia and the impurities to migrate to the slag, thereby forming purified silicon;
• solidifying the purified silicon;
• and
• separating the slag from the purified silicon.