SOLIDIFICATION AND PURIFICATION OF METAL SILICON, DEVICE THEREFOR, AND MOLD USED FOR THE DEVICE

PURPOSE: To continuously produce a purified long silicon ingot in good productivity by continuously solidifying melted metal silicon in a direction to concentrate impurities in a liquid phase, and subsequently discharging the concentrated liquid phase from a mold. CONSTITUTION: A silicon rod 7 containing impure elements is thermally melted with electron beams 9 from an electron gun 1 at a place above a water-cooling copper mold 2, and the melted product is dropped into the water-cooling mold 2. When the dropped melted silicon 9 is gradually lowered with a lowering device 4, the melted silicon 9 is solidified in a direction from the lowest part to the upper direction to given silicon ingot 3. The impure elements are concentrated in the non-solidified melted silicon 9. When the concentration of the impure elements in the silicon liquid phase or in the solid phase reaches a target value, the melting of the silicon rod 7 and the lowering of the ingot 3 are stopped, and the melted silicon 9 in the upper part of the water-cooling mold 2 is discharged from a discharging opening 5 into a receiver 6. Subsequently, the silicon rod 7 is again melted, and the lowering of the silicon ingot 3 is again continued.