Polycrystalline silicon wastewater treatment method

Abstract

The invention discloses a polycrystalline silicon wastewater treatment method which comprises the following steps: (1) adjusting polycrystalline silicon wastewater through a pretreatment tank, and pumping the adjusted polycrystalline silicon wastewater into a primary sedimentation tank for flocculation and sedimentation; (2) carrying out physicochemical treatment on the silicon powder and silicon carbide mixture; (3) conveying the supernate to a filter for filtering; (4) conveying the filtrate to a weak acid cation bed to remove weak acid ions, and then conveying the filtrate to a carbon remover to remove carbon dioxide; (5) conveying the filtrate without carbon dioxide to a reverse osmosis tank for concentration and separation; (6) conveying the concentrated solution to a secondary sedimentation tank for flocculation and sedimentation treatment; (7) carrying out evaporative crystallization treatment on the high-salinity wastewater subjected to flocculent precipitation; (8) conveying the sludge mixture subjected to flocculent precipitation to a concentration tank for concentration; (9) conveying the concentrated slurry to a filter press for solid-liquid separation; and (10) conveying the slurry blocks to a drying machine for drying. The treatment method is simple and reliable, the production cost is reduced, and the ecological environment is protected.

Description

technical field [0001] The invention relates to the technical field of polysilicon, in particular to a method for treating polysilicon wastewater. Background technique [0002] With the advancement of science and technology and the improvement of environmental protection awareness, the production and use of solar photovoltaic materials have entered a stage of rapid growth; polysilicon is an important raw material for solar photovoltaic materials, and its industrial production demand has also increased rapidly. Polysilicon mainly adopts multi-wire cutting technology. During the cutting process, about 50% of the silicon material is mixed into the cutting fluid composed of polyethylene glycol cutting fluid and silicon carbide powder abrasive, so that the composition, particle size, and hardness of the micropowder in the cutting fluid All of them do not meet the standards, resulting in a decline in cutting performance and cannot be reused. Therefore, during the cutting process, ...

AI Technical Summary

Problems solved by technology

However, as the environmental protection awareness of the whole people continues to strengthen, the environmental protection discharge standards for wastewater are also continuously improving. This treatment method needs to be improved, and this treatment method will also bring high sewage discharge costs.

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