Patent ID: 7955433

Claim:
A method for forming a silicon ingot using a low-grade silicon feedstock, the silicon ingot comprising higher grade silicon than the low-grade silicon feedstock, comprising the steps of: forming within a crucible device a molten silicon from a low-grade silicon feedstock; performing a directional solidification of the molten silicon to form a silicon ingot within the crucible device, the directional solidification forming a generally solidified quantity of silicon and a generally molten quantity of silicon, the directional solidification increasing the height of the combined solidified and molten quantity of silicon; removing from the crucible device at least a portion of the generally molten quantity of silicon while retaining within the crucible device the generally solidified quantity of silicon, wherein said removing comprises flowing the at least a portion of the generally molten quantity of silicon via a pathway associated with said crucible device, wherein the increase of the height allows the at least a portion of the generally molten quantity of silicon to reach the height of the pathway; and controlling said directional solidification of said generally solidified quantity of silicon to form a silicon ingot possessing a generally higher grade of silicon than said low-grade silicon feedstock.