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Method for treating waste liquid of monocrystalline silicon wafer flocking

A technology of single crystal silicon wafer and treatment method, which is applied in the directions of post-processing, post-processing details, natural water treatment, etc., and can solve the problems such as failure of texturing waste liquid

Active Publication Date: 2018-06-01
HUHOU FUYOUDE MEMBRANE SEPARATION TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, if the concentration of sodium silicate is too high, it will cause "flower basket printing" on the contact part between the silicon wafer and the frame of the cassette, and the concentration of sodium silicate can only be adjusted by discharging the solution, so the texturing solution needs to be replaced constantly. A large amount of texturing waste liquid is produced, but the discharged texturing waste liquid is not completely ineffective. How to recycle the active ingredients is to reduce the amount of chemicals, reduce the discharge of organic sewage, and relieve environmental pressure. Monocrystalline silicon production wastewater treatment important research direction

Method used

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  • Method for treating waste liquid of monocrystalline silicon wafer flocking

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Experimental program
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Effect test

Embodiment 1

[0027] Such as figure 1 As shown, a treatment method for monocrystalline silicon wafer texturing waste liquid, from the waste liquid tank 1, the single crystal silicon wafer texturing waste liquid is sent to the crude steam tower 2 for binary azeotropic distillation at the top to obtain a water content of 12.6% crude isopropanol, the mass concentration ranges of sodium hydroxide and sodium silicate obtained at the bottom of the tower are respectively 10% to 15% and 15% to 20% aqueous solution; the aqueous solution is sent to extraction tower 4 for sodium hydroxide Extraction, the extraction agent is saturated potassium acetate ethylene glycol, the mass ratio of the extraction agent to sodium hydroxide is 1:3, the extraction temperature is 40°C, the time range is 1.5 to 2 hours, the extraction temperature is 80°C, the tower top Obtain the extractant solution of the sodium hydroxide of oil phase, obtain the aqueous solution of the sodium silicate of water phase at the bottom of ...

Embodiment 2

[0030] Adopting the process flow similar to that in Example 1, the mass concentration ranges of sodium hydroxide and sodium silicate obtained at the bottom of the rough distillation tower 2 are respectively 15% to 20% and 10% to 15% aqueous solution; The extraction agent used in the extraction is ethylene glycol, the mass ratio of the extraction agent to sodium hydroxide is 1:2, the extraction temperature is 35°C, the time range is 2 to 2.5 hours, and the extraction temperature is 82°C; The nitrogen pressure of the distiller 6 that the stripping agent solution carries out nitrogen-filling distillation is 0.15MPa, and temperature is 150 ℃, and time range is 15~20 minutes; During dehydration, the mass ratio of solid sodium hydroxide to crude isopropanol is 1:12 to 1:9, stirred, and left to stand to obtain an isopropanol layer and a sodium hydroxide aqueous solution layer with a water content of less than 2.5%; the obtained The isopropanol with a water content of less than 2.5% i...

Embodiment 3

[0032] Adopting the process flow similar to that in Example 1, the mass concentration ranges of sodium hydroxide and sodium silicate obtained at the bottom of the rough distillation tower 2 are respectively 20% to 25% and 15% to 20% aqueous solution; The extraction agent used in the extraction is C6 oil, the mass ratio of the extraction agent to sodium hydroxide is 1:1.5, the extraction temperature is 45°C, the time range is 2.3 to 2.8 hours, and the extraction temperature is 78°C; The nitrogen pressure of the distiller 6 where the stripping agent solution is subjected to nitrogen-filled distillation is 0.18MPa, the temperature is 150°C, and the time range is 18 to 25 minutes; use the prepared solid sodium hydroxide as a dehydrating agent to dehydrate the crude isopropanol , the mass ratio of solid sodium hydroxide to crude isopropanol is 1:8.5 to 1:6.5, stirred and left to stand to obtain an isopropanol layer and a sodium hydroxide aqueous solution layer with a water content l...

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Abstract

The invention discloses a method for treating a waste liquid of monocrystalline silicon wafer flocking. The method comprises the following steps: dividing the waste liquid into crude isopropanol withwater content of 12.6% and a mixed solution of sodium hydroxide and sodium silicate through rough steaming, dividing the mixed solution of sodium hydroxide and sodium silicate into a sodium hydroxidesolution and a sodium silicate solution by extraction and back extraction, and directly recycling the sodium silicate solution to multiple industrial fields; distilling the sodium hydroxide solution by nitrogen charge and distillation to form solid sodium hydroxide, using solid sodium hydroxide as a dehydrating agent to dehydrate crude isopropanol or recycling solid sodium hydroxide in monocrystalline silicon wafer flocking, performing constant boiling distillation on dehydrated isopropanol to obtain high-purity isopropanol with water content lower than 0.5%. High recycling and harmless discharge of the waste liquid of the monocrystalline silicon wafer flocking are realized, consumption of chemical raw materials is reduced, the discharge and treatment cost of organic wastewater is reduced,and the environment is protected while the production cost is reduced.

Description

technical field [0001] The invention relates to the field of sewage treatment in the solar energy industry, in particular to a method for treating monocrystalline silicon wafer texturing waste liquid. Background technique [0002] Due to its excellent properties of safety, less pollution, recyclability and unlimited resources, solar energy has become an indispensable clean energy for human development. Compared with the availability of other energy sources, it has obvious advantages. China's photovoltaic industry has developed rapidly since 2004. At present, the output of solar cells has ranked first in the world for many years in a row, the photovoltaic power generation market has gradually started to take shape, and the industry as a whole is booming. However, the solar cell production process itself will produce a variety of waste gas, waste water and waste residue with complex components. If it cannot be treated in a timely and effective manner, it will cause serious pol...

Claims

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Application Information

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IPC IPC(8): C30B33/10C07C29/74C07C29/76C07C29/82C07C29/80C07C31/10C01B33/32C02F9/10C02F103/34
CPCC01B33/325C02F1/04C02F1/26C02F2103/34C07C29/74C07C29/76C07C29/80C07C29/82C30B33/10C07C31/10
Inventor 杨帆
Owner HUHOU FUYOUDE MEMBRANE SEPARATION TECH CO LTD