| 摘要 |
PURPOSE: To obtain the silicon seeds having a desired particle diameter and advantageous for the production of polycrystalline silicon powder in high productivity and in a high yield by subjecting polycrystlline silicon blocks to a coarsely grinding process and a finely grinding process. CONSTITUTION: A coarsely grinding process using an impact type coarsely grinding machine comprising a hammer crasher gives coarse silicon granules having granule diameters of <=10mm, and granules having diameter of >833μm are included in an amount of >=40wt.%. In the pin mill 30 of a finely grinding process using an impact type finely grinding machine, the coarse silicon granules are guided into a finely grinding chamber 32 through a feeding passage 52 and an introduction passage 50, and subsequently finely impact-ground by the cooperation of pins 48 implanted on a rotated rotary disk 46 with pins 42 implanted on a stationary disk 40. The obtained fine powder having particle diameters of <=35μm is discharged from a discharging port 58 through a screen 56, and the fine powder having particle diameters of 104-350μm is subsequently received in a container. Since the silicon is processed through the coarse grinding process and the fine grinding process, the production of excessively small fine particles is prevented and the production yield of the fine particles is improved in comparison with the cases wherein the silicon is directly ground.
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