A process for resource utilization treatment of polycrystalline silicon material production wastewater

Abstract

The invention discloses a resource utilization treatment process for polycrystalline silicon material production wastewater, aiming at the water quality characteristics of polycrystalline silicon material production wastewater (large water volume and uneven distribution, many pollutants, and many sources of sewage) , using electro-oxidation and ultrasonic advanced oxidation to remove COD and organic matter, using an ultrafiltration system to recover silicon powder, and adding CaCl 2 Fluoride removal combined with ultrafiltration system to remove precipitated CaF 2 , the waste water from the silicon chip acid etching leaching tower enters the acid recovery system to recover acid, then enters the ultrafiltration system to recover silicon powder, and then adds CaCl 2 After defluorination, the remaining clear liquid enters the denitrification system; the denitrification system adopts membrane separation technology to denitrify and enters the desalination system; Evaporation and desalination. The waste water resource utilization treatment process of the polycrystalline silicon material production of the present invention has high system stability, low operation cost, and the treatment water quality reaches the standard and is stable and efficient.

Description

technical field [0001] The invention belongs to the technical field of waste water treatment, and in particular relates to a resource utilization treatment process for waste water produced by polycrystalline silicon materials. Background technique [0002] Silicon single crystal polished wafer is the most basic and most demanded raw material for the production of integrated circuits. The integrated circuit industry is one of the top ten key industries in the world, and the supporting silicon material substrate wafer (silicon single crystal polished wafer) is also particularly important. [0003] Silicon single crystal polished wafers are made of electronic grade polysilicon with a purity of 99.999999999% as raw material. The production process is polysilicon raw material ingredients (adding boron, phosphorus, arsenic, antimony) → furnace loading → crystal pulling → furnace dismantling → single crystal silicon material sorting → slicing → Grinding→surface treatment→polishing→...

AI Technical Summary

Problems solved by technology

[0005] This treatment technology mainly has the following problems: the pre-treated water does not meet the indicators for biochemical treatment, the biochemical treatment cannot operate normally, and a large number of useful components contained in wastewater cannot be recycled reasonably and comprehensive utilization of resources has not been achieved. , high treatment cost, cumbersome operation and long treatment time, large equipment footprint, high chemical consumption, poor operation reliability, and poor effluent quality

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