| 摘要 |
<p>The present invention is a method for purifying silicon by separating out crystalline silicon from an aluminum-silicon melt at a temperature lower than the melting point of silicon using a eutectic reaction. Disposed are a conductive cold crucible (7) in which at least some of the axial wall has been split into plural portions along the circumferential direction, an induction coil (8) that surrounds the cold crucible (7), and a support table (14) placed under the cold crucible (7). While introducing solid raw materials comprising aluminum, silicon, and other elements into the cold crucible (7), the solid raw materials are melted in the cold crucible (7) by electromagnetic induction with the induction coil (8) at a temperature which is lower than the melting point of silicon but is higher than the eutectic temperature, and crystalline silicon is caused to successively separate out at the solidification interface located beneath the aluminum-silicon melt. Simultaneously therewith, the crystalline silicon which has separated out is lowered with the support table (14). Thus, silicon is caused to successively undergo directional solidification, while cooling the melt from underneath, to thereby produce a silicon ingot (3).</p> |
