| 摘要 |
PROBLEM TO BE SOLVED: To produce a silicon material for solar cells in high yield by feeding back to an appropriate treating process the silicon wastes derived from respective metallic silicon production processes comprising a vapor dephosphorization vacuum refining process, a rough refining solidification process for removal of metallic impurities, the first cutting process for densified parts of impurities, a crushing process, an oxidative refining process of boron and carbon elements, a deoxidization refining, a finishing solidification refining process, the second cutting process for densified parts of impurities and an ingot slicing process. SOLUTION: This method lies in improving the yield of a silicon material for solar cells by recycling removed silicon wastes such as cut silicon scraps, vaporized silicon substances, etc., via any proper process when a silicon material having its purity suitable for solar cells is produced using only metallurgical process provided with the figured nine processes comprising those from a process A of dephosphorizing a metallic silicon material by vacuum refining to a process I of making up solar cell substrates by slicing refined ingots. The relationships between the producing steps of the silicon wastes and the appropriate recycling steps therefor are designated by arrows as follows: A, C→A, E; D→A; I→E, etc. |
