CN111101157A - Zero-emission treatment process for PCB etching waste liquid - Google Patents
Zero-emission treatment process for PCB etching waste liquid Download PDFInfo
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- CN111101157A CN111101157A CN201911378466.4A CN201911378466A CN111101157A CN 111101157 A CN111101157 A CN 111101157A CN 201911378466 A CN201911378466 A CN 201911378466A CN 111101157 A CN111101157 A CN 111101157A
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C5/00—Electrolytic production, recovery or refining of metal powders or porous metal masses
- C25C5/02—Electrolytic production, recovery or refining of metal powders or porous metal masses from solutions
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F1/00—Etching metallic material by chemical means
- C23F1/46—Regeneration of etching compositions
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
- C25C7/06—Operating or servicing
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- Organic Chemistry (AREA)
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- General Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Electrolytic Production Of Metals (AREA)
- Water Treatment By Electricity Or Magnetism (AREA)
Abstract
The invention discloses a PCB etching waste liquid zero-emission treatment process, which comprises an electrolysis copper recovery treatment system, an MVR evaporation crystallization system and a waste gas treatment system, wherein the electrolysis copper recovery treatment system comprises a copper-containing waste water adjusting box and an electrolysis copper recovery device, the MVR evaporation crystallization system comprises an evaporation water tank, an MVR evaporator and an evaporation water outlet tank, the waste gas treatment system comprises a two-stage alkali absorption tower, the electrolysis copper recovery treatment system, the MVR evaporation crystallization system and the waste gas treatment system are jointly connected with an intermediate water tank, the intermediate water tank is also communicated with etching line meeting equipment, and the MVR evaporation crystallization system is also connected with a centrifuge. Has the advantages that: the invention adopts the process flow combining the electrolysis recovery copper treatment system, the MVR evaporation crystallization system and the waste gas treatment system, realizes the zero-emission treatment process of the high-concentration acidic etching waste liquid generated in the PCB etching industry and the method for recovering copper, and fills the blank of the PCB etching liquid waste water zero-emission technology.
Description
Technical Field
The invention relates to the technical field of zero-emission treatment processes for high-concentration acidic waste etching liquid generated in the PCB etching industry, in particular to a zero-emission treatment process for PCB etching waste liquid.
Background
With the progress of the human industry level and the rapid development of the electronic industry, the demand of printed circuit boards is increasing, the production of PCBs becomes an important basic industry of the electronic industry, however, the national environmental protection is more important, and the discharge standard of industrial wastewater is more strict. The efficient and reasonable treatment of the PCB manufacturing industry which generates a large amount of toxic and harmful industrial waste water and waste is necessary. Particularly, zero emission treatment is carried out on the PCB acid etching solution, so that copper resources can be recycled, and online recycling of water resources is realized. And the zero discharge treatment of the PCB acid etching solution is really realized.
At present, in the PCB manufacturing industry, neutralization precipitation method, solvent extraction, membrane electrolysis, reduction separation and other methods are commonly adopted for the treatment of PCB acid etching solution at home and abroad. The copper ions in the waste liquid are separated and recovered, while the residual component waste water is not substantially treated, so that secondary pollution is easily caused, and water resources are wasted.
For example, a method for extracting copper from a waste acid etching solution of a printed circuit board (patent No. CN 101353795A). The technology utilizes a membrane electrolysis technology to electrolyze and recover copper powder, and the technology can recover copper ions. However, chlorine generated in the electrolysis process is not effectively treated, and meanwhile, the waste etching solution after electrolysis is not further treated, so that secondary pollution is serious.
Therefore, the zero discharge treatment process of the high-concentration acidic etching wastewater generated in the PCB etching industry is realized, and the copper resource is recycled. There is a need for a zero-emission treatment process for generating high-concentration acidic waste etching solution and a method for recovering copper in the PCB etching industry.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provides a PCB etching waste liquid zero-emission treatment process.
In order to achieve the purpose, the invention adopts the following technical scheme:
a PCB etching waste liquid zero-emission treatment process comprises an electrolysis recovery copper treatment system, an MVR evaporation crystallization system and a waste gas treatment system, wherein the electrolysis recovery copper treatment system comprises a copper-containing waste water adjusting box and an electrolysis recovery copper device, the MVR evaporation crystallization system comprises an evaporation water tank, an MVR evaporator and an evaporation water outlet box, the waste gas treatment system comprises a two-stage alkali absorption tower, the electrolysis recovery copper treatment system, the MVR evaporation crystallization system and the waste gas treatment system are jointly connected with an intermediate water tank, the intermediate water tank is also communicated with etching line meeting equipment, and the MVR evaporation crystallization system is also connected with a centrifuge; the specific process steps are as follows:
s1: the etching solution wastewater passes through electrolytic copper recovery equipment, and the concentration of copper ions is reduced to 1g/L after treatment;
s2: transferring to an evaporation water tank for temporary storage;
s3: carrying out distillation crystallization;
s4: and (4) treating waste gas.
In the PCB etching waste liquid zero-emission treatment process, the electrolysis copper recovery device adopts 500A high-frequency direct current for electrolysis.
In the PCB etching waste liquid zero-emission treatment process, the etching waste liquid in the etching line equipment is changed into the etching waste liquid with low copper content and low ORP.
Compared with the prior art, the invention has the advantages that:
1. the invention adopts the process flow combining the electrolytic recovery copper treatment system, the MVR evaporative crystallization system and the waste gas treatment system, realizes the zero-emission treatment process of the high-concentration acidic etching waste liquid and the method for recovering copper generated in the PCB etching industry, and fills the blank of the PCB etching liquid waste water zero-emission technology;
2. the equipment has mature technology and stable process, and is suitable for zero discharge treatment of the waste water generated by the etching solution in the PCB industry;
3. the method recovers the copper, the recovery rate of the copper can reach more than 95 percent, the wastewater can be recycled by 99 percent, and the zero-emission treatment requirement is met;
4. the invention has no byproduct solid waste, is a resource with market value, and has the advantages of high water resource utilization efficiency and the like.
Drawings
FIG. 1 is a process flow diagram of a PCB etching waste liquid zero-emission treatment process provided by the invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.
Referring to fig. 1, a zero discharge treatment process of a PCB etching waste liquid comprises an electrolysis copper recovery treatment system, an MVR evaporation crystallization system and a waste gas treatment system, wherein the electrolysis copper recovery treatment system comprises a copper-containing waste water regulating box and an electrolysis copper recovery device, the MVR evaporation crystallization system comprises a water evaporation tank, an MVR evaporator and an evaporation water outlet tank, the waste gas treatment system comprises a two-stage alkali absorption tower, the electrolysis copper recovery treatment system, the MVR evaporation crystallization system and the waste gas treatment system are jointly connected with an intermediate water tank, the intermediate water tank is also communicated with etching line meeting equipment, and the MVR evaporation crystallization system is also connected with a centrifuge;
specifically, the method comprises the following steps: the etching solution waste water firstly passes through electrolytic copper recovery equipment, the concentration of treated copper ions is reduced to 1g/L, the low-concentration etching solution after electrolysis is recycled on line, and a proper amount of oxidant and hydrochloric acid are required to be additionally added during recycling, so that about 30% of etching solution is added, and the surplus 30% of etching solution is lifted to a water tank to be evaporated through a lifting pump for temporary storage. In addition, a large amount of chlorine is generated during electrolysis, alkali liquor is required to be used for absorbing the chlorine generated during electrolysis, the chlorine is absorbed and then lifted to a water tank to be evaporated through a self-priming pump to be mixed with the rest 30% low-concentration etching solution, the pH value is adjusted to 8, evaporation crystallization is carried out, part of the evaporated water is recycled to the production line, and the other part of the evaporated water is used for absorbing the chlorine as the configured alkali liquor. Sodium chloride crystals produced by evaporative crystallization of MVR can be sold as commercial salt. Thereby realizing the zero-emission treatment process of the high-concentration acidic etching waste liquid generated in the PCB etching industry and the method for recovering copper;
a zero-emission treatment process for high-concentration acidic waste etching liquid generated in the PCB etching industry and a method for recovering copper are disclosed, wherein a diaphragm electrolysis process is adopted for regeneration circulation and copper recovery. Under the action of 500A high-frequency direct current electrolysis, cathode copper is separated out from the cathode plate, Cu < + > and Cu2 < + > in the etching waste liquid are subjected to electron reduction to form a metal Cu simple substance (a copper plate is formed, separation is convenient), and the etching waste liquid is changed into etching waste liquid with low copper content and low ORP; the etching waste liquid with low copper content and low ORP permeates into the anode chamber through the polymer diaphragm, and under the action of an anode electrolysis product Cl2, the etching liquid with low copper content and low ORP is changed into the etching liquid with low copper content and high ORP, so that the characteristics of etching additive sub-liquid are met, and the etching additive sub-liquid can be added into a production line for use, and the purpose of recycling is achieved.
Adding etching waste liquid with 30% of extra copper content in the sub-night, and simultaneously absorbing chlorine gas by using a two-stage alkali absorption tower to generate sodium chloride solution, so that the two solutions are mixed in an intermediate water tank, adjusting the pH value to 8, performing MVR evaporation crystallization treatment, wherein one part of evaporation condensed water is used for supplementing water sources required by the two-stage alkali absorption tower, the other part of evaporation condensed water can be used for production line recycling or used as raw water of a water purifier, and sodium chloride crystal salt generated by MVR can be sold as industrial salt.
Further, unless otherwise specifically stated or limited, the above-described fixed connection is to be understood in a broad sense, and may be, for example, welded, glued, or integrally formed as is conventional in the art.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical scope of the present invention and the equivalent alternatives or modifications according to the technical solution and the inventive concept of the present invention within the technical scope of the present invention.
Claims (3)
1. A PCB etching waste liquid zero discharge treatment process comprises an electrolysis recovery copper treatment system, an MVR evaporation crystallization system and a waste gas treatment system, and is characterized in that the electrolysis recovery copper treatment system comprises a copper-containing waste water adjusting box and an electrolysis recovery copper device, the MVR evaporation crystallization system comprises an evaporation water tank, an MVR evaporator and an evaporation water outlet tank, the waste gas treatment system comprises a two-stage alkali absorption tower, the electrolysis recovery copper treatment system, the MVR evaporation crystallization system and the waste gas treatment system are jointly connected with an intermediate water tank, the intermediate water tank is also communicated with etching line meeting equipment, and the MVR evaporation crystallization system is also connected with a centrifuge; the specific process steps are as follows:
s1: the etching solution wastewater passes through electrolytic copper recovery equipment, and the concentration of copper ions is reduced to 1g/L after treatment;
s2: transferring to an evaporation water tank for temporary storage;
s3: carrying out distillation crystallization;
s4: and (4) treating waste gas.
2. The PCB etching waste liquid zero-emission treatment process as claimed in claim 1, wherein the electrolysis copper recovery device adopts 500A high-frequency direct current for electrolysis.
3. The PCB etching waste liquid zero-emission treatment process of claim 1, wherein the etching line meeting equipment is used for changing the etching waste liquid into the etching waste liquid with low copper content and low ORP.
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| CN201911378466.4A CN111101157A (en) | 2019-12-27 | 2019-12-27 | Zero-emission treatment process for PCB etching waste liquid |
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2019
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| CN102502998A (en) * | 2011-11-28 | 2012-06-20 | 昆山联鼎环保科技有限公司 | Totally enclosed type alkali etching liquid recycling process |
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| CN109019640A (en) * | 2018-08-30 | 2018-12-18 | 深圳市深投环保科技有限公司 | The recoverying and utilizing method of ammonium chloride MVR evaporative crystallization mother liquor |
| CN110217934A (en) * | 2019-07-22 | 2019-09-10 | 四川省川南酿造有限公司 | A kind of preparation method of pickled vegetable brine MVR evaporative crystallization |
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