| 摘要 |
The present invention relates to a method for producing high purity silicon comprising providing molten silicon containing 1-10% by weight of calcium, casting the molten silicon, crushing the silicon and subjecting the crushed silicon to a first leaching step in an aqueous solution of HCI and/or HCI + FeCI3 and to a second leaching step in an aqueous solution of HF and HNO3. The leached silicon particles is thereafter subjected to heat treatment at a temperature of between 1250°C and 14200C for a period of at least 20 minutes and the heat treated silicon is subjected to a third leaching step in an aqueous solution of HF and HNO3. |
