Method for recycling PCB (printed circuit board) acidic etching solution under photocatalytic actions

A technology of photocatalysis and etching waste liquid, which is applied in the direction of chemical instruments and methods, preparation of organic compounds, physical/chemical process catalysts, etc., can solve problems such as high investment requirements for sewage treatment equipment, complex wastewater quality, and environmental pollution, and achieve Significant economic value and social and environmental benefits, broad promotion prospects, and simple process equipment

Inactive Publication Date: 2016-05-25
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Acidic etching waste liquid seriously pollutes the environment, affects the survival of microorganisms in water, destroys the structure of soil aggregates, and affects the growth of crops
The existing recycling technologies for acidic etching solutions have obvious defects. Due to the limitations of recycling costs, regeneration solution quality, control difficulty, process continuity, etc., as well as the lack of equipment investment capabilities of small and medium-sized enterprises, most of them use The factory of the acid etching process does not adopt the recycling process, but transfers the waste liquid to the environmental protection company for treatment
[0004] Although in accordance with the relevant regulations, the relevant departments require the centralized treatment of industrial wastewater, but the centralized treatment of PCB etching liquid wastewater inevitably has the following problems: First, the operating cost of sewage treatment is relatively high, because the wastewater comes from different production processes, Therefore, the quality of wastewater is very complex, and a single treatment process cannot solve all the problems. Therefore, to achieve standard discharge of wastewater in industrial parks that are difficult to treat, a combined process of physics-chemistry-biology is used, and chemical methods such as dosing chemica...

Method used

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  • Method for recycling PCB (printed circuit board) acidic etching solution under photocatalytic actions

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Composite materials of photocatalyst / non-metallic conductor (reduced graphene oxide RGO / C 3 N 4 Composite) was prepared as follows:

[0035] (1) Carbon nitride (C 3 N 4 ) preparation: melamine is calcined and then ground to obtain carbon nitride (C 3 N 4 ) light yellow powder, the calcination temperature is 550°C, and the calcination time is 4h.

[0036] (2) Preparation of GO:

[0037] (a) Dissolve 2.5g of graphite powder and 1.25g of sodium nitrate in 60ml of concentrated sulfuric acid with a mass concentration of 95%, and place it in an ice bath for 30min.

[0038] (b) Add 7.5g of potassium permanganate and stir at room temperature for 12 hours.

[0039] (c) Add 75ml of deionized water, stir at high temperature, the temperature is 90°C, and the stirring time is 24h.

[0040] (d) adding 25 ml of hydrogen peroxide solution with a mass concentration of 30% while stirring to obtain a mixture.

[0041] (e) The mixture was centrifuged, and the product was washed with...

Embodiment 2

[0056] Photocatalyst / non-metallic conductor composites (g-C 3 N 4 -TiO 2 Composite materials) are prepared as follows:

[0057] 1. Carbon nitride (C 3 N 4 ) preparation: melamine is calcined and then ground to obtain carbon nitride (C 3 N 4 ) light yellow powder, the calcination temperature is 450°C, and the calcination time is 4h.

[0058] 2. Weigh 1.0gC 3 N 4 powder and 1.0g TiO 2 Powder, mix and grind the two in an agate mortar, then put the mixture into a hydrothermal reaction kettle, seal it and react in a muffle furnace at 550°C for 4h (heating rate is 2.0°C / min); get g-C 3 N 4 -TiO 2 composite material.

[0059] Below in conjunction with accompanying drawing and embodiment the present invention will be further described:

[0060] like figure 1 As shown, the technical scheme adopted in the recovery method of copper in the circuit board etching waste liquid of the present invention comprises the following steps:

[0061] 1. The acid etching solution is take...

Embodiment 3

[0069] Composite material of photocatalyst / non-metallic conductor (mpg-C 3 N 4 / RGO composites) were prepared as follows:

[0070] (1) Carbon nitride (C 3 N 4 ) preparation: melamine is calcined and then ground to obtain carbon nitride (C 3 N 4 ) light yellow powder, the calcination temperature is 450°C, and the calcination time is 4h.

[0071] (2) mpg-C 3 N 4 Preparation: 12gC 3 N 4 The powder was dissolved in 30 g of a 40% silica sol aqueous solution, and the mixture was evaporated to dryness. The obtained white powder was put into a combustion boat, and then sent into a tube furnace. Under the protection of 300mL / min nitrogen, the temperature was raised to 550°C at 2.3°C / min, maintained at this temperature for 4h, and cooled to room temperature naturally. A brownish-yellow powder was obtained, which was treated with 4mol / L ammonium bifluoride solution for 48h to remove the template agent. After the reaction, the solution was centrifuged to discard the supernatant...

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Abstract

The invention discloses a method for recycling a PCB (printed circuit board) acidic etching solution under photocatalytic actions. The method comprises the following steps: an etching waste solution overflowing from an etching cylinder on the production line flows into a waste solution collection tank; the etching waste solution flows into an oxidation reaction tank from the waste solution collection tank, and reacts by adding a photocatalyst under lighting conditions; the oxidated waste solution flows into a precipitation reaction kettle provided with a cation exchange membrane, and meanwhile, a precipitant is added to form a precipitate-containing mixed solution; the mixed solution is subjected to solid-liquid separation; part of the filter residue is refined and purified, and then is sold in the form of cupric oxalate, and the rest is decomposed into activated copper oxide for sale; the filtrate flows into a dewatering system after hydrochloric acid is supplemented, thereby removing excessive moisture; and finally, the filtrate flows into a storage tank to become the recycled solution for etching. The copper is reutilized in the technical process: the copper is extracted properly by balanced operation, and part of copper is recycled. Only a certain amount of clean water is discharged, and no waste solution is discharged, thereby implementing closed cycle production. The process is simple in equipment and convenient to control, has wide popularization prospects, and has obvious economic value and social and environmental benefits.

Description

technical field [0001] The invention relates to the field of recycling and utilization of circuit board etching waste liquid, in particular to a method for recycling and utilizing photocatalytic PCB acidic etching liquid. Background technique [0002] The printed circuit board (PCB) industry is one of the most important components in the electronic industry, and plays a pivotal role in the electronic information industry. In recent years, with the rapid development of the electronic industry, the demand for PCB is increasing day by day. Acid etching is an important process in the manufacture of printed circuit boards (PCB). A large amount of high-copper etching waste liquid is produced during the production process. The etching waste liquid is a hazardous liquid waste and contains a large amount of polluting components such as copper and chlorine. If it is not treated strictly If it is directly discharged into the environment, it will not only cause waste and loss of resourc...

Claims

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Application Information

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IPC IPC(8): C23F1/46C22B7/00C22B15/00B01J27/24C07C51/41C07C55/07
CPCC23F1/46B01J27/24B01J35/004C07C51/412C22B7/006C22B15/0063C07C55/07
Inventor 黄洪邢征司徒粤
Owner SOUTH CHINA UNIV OF TECH
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