Preparation device and preparation method for silicon ball

Abstract

The invention discloses a preparation device and a preparation method for a silicon ball and relates to a silicon ball. The preparation device for the silicon ball comprises an induction coil, a graphite insulation board, a graphite crucible, a flow divider, a cooling tank, a water inlet pipe, a water outlet pipe, a gas inlet pipe and an electric pump. The preparation method for the silicon ball comprises the following steps of: using a metallurgical-grade silicon material as the raw material and placing the silicon material into the crucible of an induction furnace; starting an induction furnace power supply to heat and after totally melting the silicon material, adding a slag forming constituent; after completing slag forming, switching off the induction furnace power supply; standing and removing waste residues floating at the upper part of the crucible to obtain silicon liquid; starting the flow divider to carry out preheating and when the temperature in the flow divider reaches the range of 1,450 to 1,650 DEG C, pouring the silicon liquid into the flow divider; regulating the heights of a liquid outlet at the bottom of the flow divider and the cooling tank to enable the silicon liquid to fall into the cooling tank in a droplet shape to be quenched; and filling gas into the cooling tank and after completing quenching, and obtaining the silicon ball. Boron content can be obviously reduced; the obtained silicon ball comprises small crystal grains and is easy to crush and process; and an ideal low-boron raw material can be provided for an acid pickling process.

Description

technical field [0001] The invention relates to a silicon ball, in particular to a silicon ball preparation device and a preparation method thereof. Background technique [0002] With the increasingly serious energy crisis, the development of sustainable and environmentally friendly new energy has become a hot spot of global concern. As a clean, efficient and renewable new energy, solar energy has become the focus of new energy development in various countries. At present, among many types of solar cells, polysilicon is the main raw material for preparing solar cells. The preparation technology of metallurgical solar-grade polysilicon has the characteristics of simple process, low cost and low environmental pollution, and will become an important way for the new preparation technology of solar-grade polysilicon. The purity of raw silicon usually used to prepare solar cells should not be lower than 99.9999%, and the content of impurity element B should be less than 0.3ppmw, ...

AI Technical Summary

Problems solved by technology

Impurities are often distributed at the grain boundaries, and the cooling rate of silicon liquid is relatively slow during the cooling process of large silicon ingots, and it is not easy to form silicon blocks with small grains, which is not conducive to crushing and pickling removal of impurities

And in the process of powder processing, it will cause secondary pollution of metal and increase processing cost

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