CN115928079A - Zero-increment online recovery method for alkaline etching waste liquid - Google Patents
Zero-increment online recovery method for alkaline etching waste liquid Download PDFInfo
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- CN115928079A CN115928079A CN202211604927.7A CN202211604927A CN115928079A CN 115928079 A CN115928079 A CN 115928079A CN 202211604927 A CN202211604927 A CN 202211604927A CN 115928079 A CN115928079 A CN 115928079A
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- alkaline etching
- waste liquid
- etching waste
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- 239000007788 liquid Substances 0.000 title claims abstract description 133
- 238000005530 etching Methods 0.000 title claims abstract description 86
- 239000002699 waste material Substances 0.000 title claims abstract description 62
- 238000000034 method Methods 0.000 title claims abstract description 51
- 238000011084 recovery Methods 0.000 title claims abstract description 29
- 238000010521 absorption reaction Methods 0.000 claims abstract description 67
- 238000001704 evaporation Methods 0.000 claims abstract description 41
- 230000008020 evaporation Effects 0.000 claims abstract description 36
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 24
- 230000008569 process Effects 0.000 claims abstract description 20
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims description 38
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 28
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 23
- 229910052802 copper Inorganic materials 0.000 claims description 22
- 239000010949 copper Substances 0.000 claims description 22
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 19
- 235000019270 ammonium chloride Nutrition 0.000 claims description 19
- 238000000605 extraction Methods 0.000 claims description 17
- 230000005484 gravity Effects 0.000 claims description 16
- 238000004064 recycling Methods 0.000 claims description 13
- 238000005868 electrolysis reaction Methods 0.000 claims description 11
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 238000012544 monitoring process Methods 0.000 claims description 7
- 239000002920 hazardous waste Substances 0.000 abstract description 7
- 229910021529 ammonia Inorganic materials 0.000 abstract description 6
- 230000008901 benefit Effects 0.000 abstract description 6
- 230000007613 environmental effect Effects 0.000 abstract description 4
- 239000002994 raw material Substances 0.000 abstract description 2
- 239000002918 waste heat Substances 0.000 abstract description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 3
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 description 3
- 235000011114 ammonium hydroxide Nutrition 0.000 description 3
- 238000012946 outsourcing Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000002253 acid Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- ing And Chemical Polishing (AREA)
- Heat Treatment Of Water, Waste Water Or Sewage (AREA)
Abstract
The invention discloses a zero-increment online recovery method for alkaline etching waste liquid, belonging to the technical field of treatment of alkaline etching waste liquid of circuit boards. The invention adopts a combined process of low-temperature evaporation and an ammonia absorption tower, adopts multi-stage full-closed absorption of ammonia, ensures that the ammonia is completely recycled, has no raw material loss, has the evaporation temperature of 50-60 ℃, can be completely obtained by waste heat in a factory, is a low-grade heat source, can realize the gradient utilization of energy compared with the common steam evaporation, and achieves the purpose of energy saving. The invention realizes zero generation of the hazardous waste of the alkaline etching waste liquid, avoids the environmental risk in the process of transferring the hazardous waste and has obvious environmental benefit.
Description
Technical Field
The invention relates to the technical field of treatment of alkaline etching waste liquid of circuit boards, in particular to a zero-increment online recovery method of alkaline etching waste liquid
Background
In the production process of the printed circuit board, the required circuit pattern needs to be etched on the copper foil plate by using etching liquid, and the etching liquid is divided into acid and alkaline according to different etching processes. In the alkaline etching process, along with the increase of the copper etching amount, the contents of ammonia water and ammonium chloride in the etching solution are correspondingly reduced, so that the etching speed is slowed, and in order to ensure the etching quality, the copper content in the etching solution needs to be reduced, and the ammonia water, the ammonium chloride and the etching additive are supplemented to recover and maintain the etching capability. However, the added ammonia water and ammonium chloride can cause the etching solution to expand, the expanded etching solution can not be recycled, and the hazardous waste is only treated according to the outsourcing of the hazardous waste, so that on one hand, the hazardous waste risks polluting the environment, and on the other hand, due to the outsourcing treatment, the copper resource can not realize the due value.
Disclosure of Invention
The embodiment of the invention provides a zero-increment online recovery method of alkaline etching waste liquid, which combines a mature direct electrolysis or extraction electrolysis process in the market, develops a set of new processes, performs resource recycling on expanded etching waste liquid, ensures that the waste liquid does not expand in the process of extracting copper from etching liquid and recycling, realizes the full recovery of copper resources and ammonia nitrogen resources, realizes the standard discharge after the treatment of waste water and waste gas, and does not generate waste residue in the recycling process, and the content of the invention is as follows:
the invention aims to provide an alkaline etching waste liquid zero-increment online recovery method, which is technically characterized by comprising the following steps of:
firstly, evaporating and concentrating the alkaline etching waste liquid for the first time to 30-50% of the original liquid inlet volume to obtain the concentrated alkaline etching waste liquid;
absorbing the ammonia gas obtained in the evaporation concentration process in the step one in an absorption tower by hydrochloric acid to generate absorption liquid, wherein the pH value of the absorption liquid is 3-6;
monitoring the concentration of chloride ions in the absorption liquid and the specific gravity of the absorption liquid in the step two, and performing secondary concentration and evaporation on the absorption liquid to 35-60% of the original liquid inlet volume to obtain an ammonium chloride concentrated solution when the concentration of the chloride ions in the absorption liquid reaches 100-160g/L and the specific gravity of the absorption liquid reaches a preset threshold value;
fourthly, the ammonium chloride concentrated solution obtained in the third step is used for preparing alkaline etching sub-solution again and is reused in an etching production line;
and step five, directly feeding the alkaline etching waste liquid concentrated in the step one into an extraction electrolysis copper extraction system for recycling.
In order to better realize the method, the time for the first evaporation concentration in the first step of the zero-increment online recovery method of the alkaline etching waste liquid is 5-8h.
In order to better realize the method, the temperature of the first evaporation concentration in the first step of the zero-increment online recovery method of the alkaline etching waste liquid is 50-60 ℃.
In order to better realize the method, in the step I of the zero-increment online recovery method of the alkaline etching waste liquid, the copper content in the alkaline etching waste liquid is 120-140g/L, and the ammonia gas content is 10-15wt%.
In order to better realize the method, the concentration of hydrochloric acid in the step two of the zero-increment online recovery method of the alkaline etching waste liquid is 30-32wt%.
In order to better realize the method, the preset threshold value of the specific gravity of the absorption liquid in the third step of the zero-increment online recovery method for the alkaline etching waste liquid is 1.0500-1.0700.
Compared with the prior art, the zero-increment online recovery method of the alkaline etching waste liquid has the following beneficial effects:
1. the zero-increment online recovery method of the alkaline etching waste liquid realizes zero increment of the alkaline etching waste liquid, fully recovers copper resources and ammonia nitrogen resources, has high additional value of recovered products, and has obvious economic benefit.
2. The invention adopts a combined process of low-temperature evaporation and an ammonia absorption tower, adopts multi-stage full-closed absorption of ammonia, ensures that the ammonia is completely recycled, has no raw material loss, has the evaporation temperature of 50-60 ℃, can be completely obtained by waste heat in a factory, is a low-grade heat source, can realize the gradient utilization of energy compared with the common steam evaporation, and achieves the purpose of energy saving.
3. The invention realizes zero generation of the hazardous waste of the alkaline etching waste liquid, avoids the environmental risk in the process of transferring the hazardous waste and has obvious environmental benefit.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The existing copper recovery process for a PCB enterprise is extraction electrolysis copper extraction recycling, 50 tons of alkaline etching waste liquid generated in the process every month can only be sold at low price, wherein the copper content in the alkaline etching waste liquid is 120-140g/L, and the ammonia gas content is 10-15wt%. The loss of copper resources and ammonia gas resources is serious, after the zero-increment online recovery method of the alkaline etching waste liquid is adopted, the alkaline etching waste liquid can be completely treated by the method, copper is completely recovered by electrolysis, ammonia nitrogen resources are prepared into ammonium chloride for recycling, and the economic benefit is obvious.
Example 1
The zero-increment online recovery method of the alkaline etching waste liquid comprises the following steps of:
firstly, evaporating and concentrating the alkaline etching waste liquid for the first time to 40% of the original liquid inlet volume to obtain the concentrated alkaline etching waste liquid, wherein the temperature of the first evaporation and concentration in the preferred embodiment is 55 ℃, and the time of the first evaporation and concentration is 6.5 hours;
step two, absorbing the ammonia gas obtained in the evaporation concentration process in the step one by hydrochloric acid in an absorption tower to generate absorption liquid, wherein the pH of the absorption liquid is 4.5, and preferably, the concentration of the hydrochloric acid in the implementation is 31wt%;
monitoring the concentration of chloride ions in the absorption liquid and the specific gravity of the absorption liquid in the step two, and performing secondary concentration and evaporation on the absorption liquid until the concentration of the chloride ions in the absorption liquid reaches 130g/L and the specific gravity of the absorption liquid reaches 1.0600 which is a preset threshold value, so as to obtain an ammonium chloride concentrated solution, wherein the concentration of the chloride ions in the absorption liquid reaches 47.5% of the original liquid inlet volume;
fourthly, the ammonium chloride concentrated solution obtained in the third step is used for preparing alkaline etching sub-solution again and is reused in an etching production line;
and step five, directly feeding the alkaline etching waste liquid concentrated in the step one into an extraction electrolysis copper extraction system for recycling.
Example 2
The zero-increment online recovery method of the alkaline etching waste liquid comprises the following steps of:
firstly, carrying out first evaporation concentration on the alkaline etching waste liquid until the volume of the alkaline etching waste liquid is 30% of the volume of the original liquid inlet to obtain the concentrated alkaline etching waste liquid, wherein the temperature of the first evaporation concentration in the preferred embodiment is 50 ℃, and the time of the first evaporation concentration is 5 hours;
step two, absorbing the ammonia gas obtained in the evaporation concentration process in the step one by hydrochloric acid in an absorption tower to generate absorption liquid, wherein the pH of the absorption liquid is 3, and preferably, the concentration of the hydrochloric acid in the implementation is 30wt%;
monitoring the concentration of chloride ions in the absorption liquid and the specific gravity of the absorption liquid in the step two, and performing secondary concentration and evaporation on the absorption liquid until the concentration of the chloride ions in the absorption liquid reaches 100g/L and the specific gravity of the absorption liquid reaches a preset threshold value 1.0500 to obtain an ammonium chloride concentrated solution, wherein the concentration of the chloride ions in the absorption liquid is 35% of the original liquid inlet volume;
fourthly, the ammonium chloride concentrated solution obtained in the third step is used for preparing alkaline etching sub-solution again and is reused in an etching production line;
and step five, directly feeding the alkaline etching waste liquid concentrated in the step one into an extraction electrolysis copper extraction system for recycling.
Example 3
The zero-increment online recovery method of the alkaline etching waste liquid comprises the following steps of:
firstly, evaporating and concentrating the alkaline etching waste liquid for the first time to 50% of the original liquid inlet volume to obtain the concentrated alkaline etching waste liquid, wherein the temperature of the first evaporation and concentration in the preferred embodiment is 60 ℃, and the time of the first evaporation and concentration is 8 hours;
step two, absorbing the ammonia gas obtained in the evaporation concentration process in the step one by hydrochloric acid in an absorption tower to generate absorption liquid, wherein the pH of the absorption liquid is 6, and preferably, the concentration of the hydrochloric acid in the implementation is 32wt%;
monitoring the concentration of chloride ions in the absorption liquid and the specific gravity of the absorption liquid in the step two, and performing secondary concentration and evaporation on the absorption liquid until the concentration of the chloride ions in the absorption liquid reaches 160g/L and the specific gravity of the absorption liquid reaches a preset threshold value 1.0700 to obtain an ammonium chloride concentrated solution, wherein the concentration of the chloride ions in the absorption liquid reaches 60% of the original liquid inlet volume;
fourthly, the ammonium chloride concentrated solution obtained in the third step is used for preparing alkaline etching sub-solution again and is reused in an etching production line;
and step five, directly feeding the alkaline etching waste liquid concentrated in the step one into an extraction electrolysis copper extraction system for recycling.
Example 4
The zero-increment online recovery method of the alkaline etching waste liquid comprises the following steps of:
firstly, evaporating and concentrating the alkaline etching waste liquid for the first time to 35% of the original liquid inlet volume to obtain the concentrated alkaline etching waste liquid, wherein the temperature of the first evaporation and concentration in the preferred embodiment is 52 ℃, and the time of the first evaporation and concentration is 6 hours;
step two, absorbing the ammonia gas obtained in the evaporation concentration process in the step one by hydrochloric acid in an absorption tower to generate absorption liquid, wherein the pH of the absorption liquid is 4, and preferably, the concentration of the hydrochloric acid in the implementation is 30.5wt%;
monitoring the concentration of chloride ions in the absorption liquid and the specific gravity of the absorption liquid in the step two, and performing secondary concentration and evaporation on the absorption liquid until the concentration of the chloride ions in the absorption liquid reaches 110g/L and the specific gravity of the absorption liquid reaches a preset threshold value 1.0550 to obtain an ammonium chloride concentrated solution, wherein the concentration of the chloride ions in the absorption liquid is 40% of the original liquid inlet volume;
fourthly, the ammonium chloride concentrated solution obtained in the third step is used for preparing alkaline etching sub-solution again and is reused in an etching production line;
and step five, directly feeding the alkaline etching waste liquid concentrated in the step one into an extraction electrolysis copper extraction system for recycling.
Example 5
The zero-increment online recovery method of the alkaline etching waste liquid comprises the following steps of:
firstly, carrying out first evaporation concentration on the alkaline etching waste liquid to 45% of the original liquid inlet volume to obtain the concentrated alkaline etching waste liquid, wherein the temperature of the first evaporation concentration in the preferred embodiment is 57 ℃, and the time of the first evaporation concentration is 7h;
step two, absorbing the ammonia gas obtained in the evaporation concentration process in the step one by hydrochloric acid in an absorption tower to generate absorption liquid, wherein the pH of the absorption liquid is 5, and preferably, the concentration of the hydrochloric acid in the implementation is 31.5wt%;
monitoring the concentration of chloride ions in the absorption liquid and the specific gravity of the absorption liquid in the step two, and performing secondary concentration and evaporation on the absorption liquid until the concentration of the chloride ions in the absorption liquid reaches 150g/L and the specific gravity of the absorption liquid reaches a preset threshold value 1.0650 to obtain an ammonium chloride concentrated solution, wherein the concentration of the chloride ions in the absorption liquid reaches 50% of the original liquid inlet volume;
fourthly, the ammonium chloride concentrated solution obtained in the third step is used for preparing alkaline etching sub-solution again and is reused in an etching production line;
and step five, directly feeding the alkaline etching waste liquid concentrated in the step one into an extraction electrolysis copper extraction system for recycling.
In conclusion, the zero-increment online recovery treatment of the alkaline waste liquid is carried out based on the process, ammonia gas resources can be converted into ammonium chloride for recycling, low-price outsourcing copper in the waste liquid can be completely prepared into electrolytic copper for high-price recovery, the process is simple and easy to control, and the economic benefit is obvious.
The above description is only an example of the present invention and is not intended to limit the present invention. Various modifications and alterations to this invention will become apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.
Claims (6)
1. The zero-increment online recovery method of the alkaline etching waste liquid is characterized by comprising the following steps of:
firstly, evaporating and concentrating the alkaline etching waste liquid for the first time to 30-50% of the original liquid inlet volume to obtain the concentrated alkaline etching waste liquid;
step two, absorbing the ammonia gas obtained in the evaporation concentration process in the step one in an absorption tower by using hydrochloric acid to generate absorption liquid, wherein the pH value of the absorption liquid is 3-6;
monitoring the concentration of chloride ions in the absorption liquid and the specific gravity of the absorption liquid in the step two, and performing secondary concentration and evaporation on the absorption liquid to 35-60% of the original liquid inlet volume to obtain an ammonium chloride concentrated solution when the concentration of the chloride ions in the absorption liquid reaches 100-160g/L and the specific gravity of the absorption liquid reaches a preset threshold value;
fourthly, the ammonium chloride concentrated solution obtained in the third step is used for preparing alkaline etching sub-solution again and is reused in an etching production line;
and step five, directly feeding the alkaline etching waste liquid concentrated in the step one into an extraction electrolysis copper extraction system for recycling.
2. The zero-increment online recovery method for alkaline etching waste liquid as claimed in claim 1, wherein the time for the first evaporation concentration in the first step is 5-8h.
3. The zero-increment online recovery method for alkaline etching waste liquid as claimed in claim 1, wherein the temperature of the first evaporation concentration in the first step is 50-60 ℃.
4. The zero-increment online recovery method for alkaline etching waste liquid as claimed in claim 1, wherein in the step one, the copper content in the alkaline etching waste liquid is 120-140g/L, and the ammonia gas content is 10-15wt%.
5. The method for zero-increment online recovery of waste alkaline etching solution according to claim 1, wherein the concentration of hydrochloric acid in the second step is 30-32wt%.
6. The on-line zero-increment recovery method for the alkaline etching waste liquid according to claim 1, characterized in that the preset threshold value of the specific gravity of the absorption liquid in the third step is 1.0500-1.0700.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211604927.7A CN115928079A (en) | 2022-12-14 | 2022-12-14 | Zero-increment online recovery method for alkaline etching waste liquid |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202211604927.7A CN115928079A (en) | 2022-12-14 | 2022-12-14 | Zero-increment online recovery method for alkaline etching waste liquid |
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| CN115928079A true CN115928079A (en) | 2023-04-07 |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105002500A (en) * | 2015-07-17 | 2015-10-28 | 中南大学 | Alkaline CuC12 spent etching solution copper removal regeneration method |
| CN108149249A (en) * | 2017-07-05 | 2018-06-12 | 叶涛 | A kind of ammonia still process recycling circulation technology of wiring board alkaline etching waste liquid for producing |
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2022
- 2022-12-14 CN CN202211604927.7A patent/CN115928079A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105002500A (en) * | 2015-07-17 | 2015-10-28 | 中南大学 | Alkaline CuC12 spent etching solution copper removal regeneration method |
| CN108149249A (en) * | 2017-07-05 | 2018-06-12 | 叶涛 | A kind of ammonia still process recycling circulation technology of wiring board alkaline etching waste liquid for producing |
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