Technical method for preparing solar energy polycrystalline silicon by using metallurgical method

Abstract

The invention belongs to the technical field of material engineering, in particular to a preparation method of solar energy polycrystalline silicon. The technical scheme of the preparation method comprises the following steps of: adopting high-purity silica and a carbonaceous reducing agent as raw materials and carrying out carbon thermal reduction of a submerged-arc furnace, slag washing and refining, wet-process impurity removal, directional solidification, and electron beam smelting to obtain solar energy-grade polycrystalline silicon. The solar energy polycrystalline silicon with high pureness has a B content less than or equal to 0.25ppmw, a P content less than or equal to 0.43ppmw and the pureness of larger than or equal to 99.9999%. Compared with the prior art, the preparation method has the following advantages that: 1. the process of the productive technology is short; the energy consumption is low; the environmental pollution is less; the technical method is used for removing impurities in the silicon step by step in a purposeful and selective manner; and the product pureness is high; and 2. the solar energy polycrystalline silicon can be directly prepared by using the silica and can be successfully applied to large-scale high-voltage grid-connected power stations.

Description

technical field [0001] The invention belongs to the technical field of material engineering, and in particular relates to a preparation method of solar grade polysilicon. Background technique [0002] Solar power generation has the advantages of sufficient cleanliness, relatively extensive and sufficient resources, long life, and maintenance-free, which other conventional energy sources do not have. At present, silicon materials are still the most important conversion materials for solar cells, especially crystalline silicon. Solar battery. At present, the methods for preparing solar-grade polysilicon materials mainly include chemical methods and metallurgical methods. Among them, the chemical method mainly includes three methods: improved Siemens method, silane decomposition method and fluidized bed reaction method. Combination technology composition. [0003] Among the many methods for preparing solar-grade polysilicon, the low-cost production of materials is the basis ...

AI Technical Summary

Problems solved by technology

In recent years, researches on new processes, new technologies and equipment of metallurgical solar-grade polysilicon have been very active. There are many methods and technical routes for the preparation of solar polysilicon by metallurgical methods at home and abroad. Different production methods have great impact on polysilicon project investment and product quality. , Production cost and energy consumption have a great impact, but at present, except the present invention, no metallurgical solar polysilicon products produced by the technology have been found to be widely used in large-scale high-voltage grid-connected power stations