What purity of silica sand raw material is needed for high purity quartz sand?

This method uses high-purity quartz sand as raw material to produce solar-grade polysilicon. Select silica materials with a SiO2 content of more than 99%, and perform water quenching, crushing, screening, pickling, magnetic separation, and high-pressure ionization to make the purity of the silica particles reach 99.99. % or more to obtain high-purity quartz sand.

Chloride the carbonaceous reducing agent and the graphite electrode in the submerged arc furnace at high temperature in the chlorination furnace to make the purity of the carbonaceous reducing agent reach more than 99.9999%; use carbon in the submerged arc furnace High-purity quartz sand is reduced with a high-quality reducing agent to produce silicon. During the production process, silicon liquid is regularly released from the submerged furnace; the obtained silicon liquid is injected into the holding furnace, and the product is directly subjected to high-frequency plasma blowing in a non-oxidizing atmosphere.

Impurities are removed, and oxidizing gas is added to the silicon liquid at the same time; the silicon liquid is then injected into a directional solidification furnace for directional solidification, and the silicon is further purified to obtain solar-grade polysilicon. The advantages are: low investment, short construction period, low production cost, simple process, no pollution, and suitable for industrialization.