A method for filtering and purifying waste water containing silicon powder

Abstract

The invention is a treatment for filtering and purifying siliceous powder waste water, which is a treatment method for press filtration and purification of siliceous waste water using a van-type filter press by adding perlite or diatomite flocculating agent. The system is a filtration system which is composed of a van-type filter press set, a slag slurry pump, a perlite or diatomite clear water mixing box and a mixer. The main process step comprises: adding perlite or diatomite into a clear water mixing box, fully mixing perlite or diatomite in clear water stirred by mixer, adding perlite or diatomite mixed water into a van-type filter press by the slag slurry pump, forming a perlite or diatomite filter membrane on the filter press filter cloth, and switching siliceous powder waste water to a van-type filter press for continuously filtering. The invention is used for filtering and treating siliceous powder waste water, and the filtering treatment amount is large and the water quality good is good, and the water after treatment can be reused for production and can be discharged directly without environment influence.

Description

technical field [0001] The invention relates to a method for filtering and purifying waste water containing silicon powder, which is particularly suitable for treating waste water containing small particles and slag, and belongs to the field of waste water purifying treatment. Background technique [0002] In the production process of polysilicon, a silicon core saw is used to cut silicon rods, and a large amount of silicon powder will be produced during the cutting process. The particle size of the silicon powder is usually ranging from 0.12 μm to 1 mm, while the conventional filter cloth can only filter the powder at about 1 μm. particles, which leads to the inability of the filter cloth to effectively filter silicon-containing wastewater. Due to the small particle size of silicon powder in wastewater containing silicon powder, silicon powder cannot be mixed with water for effective separation according to the original design plan, and the treated water has high turbidity,...

AI Technical Summary

Problems solved by technology

[0002] In the production process of polysilicon, a silicon core saw is used to cut silicon rods, and a large amount of silicon powder will be produced during the cutting process. The particle size of the silicon powder is usually ranging from 0.12 μm to 1 mm, while the conventional filter cloth can only filter the powder at about 1 μm. particles, which leads to the inability of the filter cloth to effectively filter silicon-containing wastewater

Due to the small particle size of silicon powder in wastewater containing silicon powder, silicon powder cannot be mixed with water for effective separation according to the original design plan, and the treated water has high turbidity, which cannot be reused and cannot meet the water requirements for silicon rod cutting. status quo

[0003] The existing conventional method for treating silicon powder-containing wastewater produced by silicon core cutting is mainly to add a component flocculant to flocculate and separate silicon powder particles, but the price of the flocculant required is relatively high, and it is inconvenient to pressurize after flocculation and stratification ;The other way is to discharge directly. Although it is simple and fast, the discharged wastewater contains a large amount of silicon powder particles, which has a great impact on the environment.

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