Device and method for preparing granular silicon seed crystal

Abstract

The invention relates to the technical field of crystalline silicon preparation and aims to provide a device and a method for preparing a granular silicon seed crystal. The device is capable of preparing the granular silicon seed crystal with high purity and sphericity, has low material loss and difficultly produces dust. The device for preparing the granular silicon seed crystal provided by the invention comprises a rotating device used for dispersing molten silicon flowing out of a guide port. The implementation process comprises the following steps: heating a polycrystalline silicon material into a molten state by a melting device so as to obtain molten polycrystalline silicon; enabling the molten polycrystalline silicon to drop onto a rotating disc rotating at a high speed via the guide port, enabling the high-speed rotating disc to throw out the dispersed polycrystalline silicon droplets along a tangential direction, and cooling and solidifying the polycrystalline silicon dropletsin air, thereby obtaining the granular silicon seed crystal. According to the method for preparing the granular silicon seed crystal provided by the invention, due to the adoption of the device for preparing the granular silicon seed crystal, the previous beneficial effects can be achieved.

Description

technical field [0001] The invention relates to the technical field of crystalline silicon preparation, in particular to a device and method for preparing granular silicon seed crystals. Background technique [0002] The improved Siemens method and the fluidized bed method are the main methods for producing polysilicon. Both methods require polysilicon seeds as the silicon deposition carrier. The improved Siemens method usually uses cylindrical polysilicon thin rods or cube-shaped polysilicon rods as the silicon deposition carrier. , The fluidized bed method uses small-sized silicon particles as the silicon deposition carrier. [0003] Granular silicon seed crystals are usually prepared by mechanical pulverization methods such as grinding and crushing. Taking the preparation of granular silicon seed crystals by the crushing method as an example, during the crushing process of polycrystalline silicon rods, there is a high probability of introducing foreign impurities and sur...

AI Technical Summary

Problems solved by technology

Irregular silicon seed crystals, that is, the higher the proportion of low-sphericity silicon seed crystals in the fluidized bed, the correspondingly the lower the minimum fluidized state velocity, and too low minimum fluidized state velocity is not conducive to the fluidized bed. The stable operation of the fluidized bed will lead to an increase in the degree of boiling of the fluidized bed, which will increase the porosity of the bed and make it easier to generate silicon dust

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