Method for recovering copper in rinsing water after copper etching

Abstract

The invention discloses a method for recovering copper from rinse water after copper etching, copper is recovered from circuit board rinse wastewater by adopting a mode of combining extraction and back extraction, and compared with single-stage extraction or a pure chemical precipitation method, an electrolytic method, an ion exchange method and an adsorption method, the method is more suitable for large-scale low-concentration rinse wastewater; copper ions can be more sufficiently and efficiently transferred into an organic extraction agent from large-scale low-concentration rinsing wastewater, copper extraction is more complete, and the extraction yield of copper is high; and the organic extraction agent can be recycled, so that the purpose of reducing the cost is achieved, copper is effectively enriched after extraction and back extraction, high-purity copper can be rapidly obtained by combining an electrolytic method, and the whole process is efficient and environmentally friendly.

Description

Technical Field

[0001] The invention relates to the technical field of copper etching recovery, in particular to a method for recovering copper from rinsing water after copper etching. Background Art

[0002] In the circuit board manufacturing process, the etching process is one of the key steps, which is used to define the circuit pattern. After etching, the circuit board must be rinsed to remove residual chemicals and metal ions, especially copper ions; this rinsing process will produce a large amount of rinsing wastewater containing copper ions; if these copper-containing rinsing wastewaters are discharged directly into the environment without treatment, they will cause serious pollution to water bodies and soil and affect the ecosystem. Although the concentration of copper ions in rinsing wastewater is low, copper, as an important non-ferrous metal, its recovery not only helps to avoid resource waste, but also generates significant economic value; in addition, through recycling, dependence on primary mineral resources can be reduced.

[0003] At present, the treatment methods for copper-containing rinsing wastewater mainly include chemical precipitation, electrolysis, ion exchange and adsorption, etc. However, the use of only one of the above methods will have certain limitations. For example, the chemical precipitation method mainly precipitates copper ions by adding chemical reagents. However, this method may introduce new chemical substances and cause secondary pollution problems; the electrolysis method uses electrochemical principles to deposit copper ions from the solution. Although this method is highly efficient, it consumes a lot of energy and is costly, and is not suitable for low-concentration wastewater treatment; for example, the ion exchange method uses specific resins or membrane materials to selectively adsorb copper ions. This method has a good effect, but the resin regeneration process is complicated and costly; the adsorption method mainly uses activated carbon or other porous materials to adsorb copper ions. This method is simple to operate, but the adsorption capacity is limited, and it is not suitable for large-scale low-concentration wastewater treatment.

[0004] Therefore, how to efficiently and environmentally friendly recover copper from large-scale low-concentration rinsing wastewater has become an important topic that needs to be studied in depth. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides an efficient and environmentally friendly method for recovering copper from rinsing water after copper etching, comprising:

[0006] Pretreatment of rinsing wastewater: After rinsing the etched circuit board with clean water, collect the rinsing wastewater into a storage tank, filter and remove impurities to obtain pretreated rinsing wastewater;

[0007] Extraction: According to the weight ratio, 1 to 5 parts of pre-treated rinsing wastewater and 1 part of the first organic extractant are mixed, stirred, and allowed to stand to extract the copper in the pre-treated rinsing wastewater to obtain a first copper-rich organic phase and a first copper-poor raffinate, a pH regulator is added to the first copper-poor raffinate to adjust the pH of the first copper-poor raffinate to 2 to 3, and then 1 part of the second organic extractant is added to every 5 to 9 parts of the first copper-poor raffinate, mixed, stirred, and allowed to stand for secondary extraction to obtain a second copper-rich organic phase and a second copper-poor raffinate (copper ion content is less than 20 mg / L), and the second copper-poor raffinate is discharged to a comprehensive sewage station for treatment; wherein the first organic extractant and the second organic extractant have the same composition, and are obtained by mixing Lix 984H extractant, kerosene, di-(2-ethylhexyl) phosphate and bis(2,4,4-trimethylpentyl)phosphinic acid;

[0008] Stripping: according to the weight ratio, 1 part of sulfuric acid solution is added to every 5 to 9 parts of the second copper-rich organic phase for mixed stripping to obtain a copper sulfate solution and a first copper-poor organic phase (copper ion content is less than 20 mg / L), the copper sulfate solution is electrolytically deposited in an electrolytic cell to recover cathode copper, wherein the anode of the electrolytic cell is titanium-based lead dioxide plated, and the cathode is a copper mother sheet, the copper sulfate solution after electrolysis (copper ion content is less than 10 g / L) is called a copper-poor electrolyte, sulfuric acid solution is added to the copper-poor electrolyte, and then mixed with the first copper-rich organic phase for stripping to obtain a copper sulfate solution and a second copper-poor organic phase, the copper sulfate solution is continuously electrolyzed to recover cathode copper, the first copper-poor organic phase is combined with the second copper-poor organic phase, and then a new first organic extractant is added to continue to repeat the extraction steps to extract new pre-treated rinse wastewater.

[0009] Preferably, during the extraction process, the first organic extractant and the second organic extractant have the same composition, and are composed of the following components in parts by weight: 1 to 5 parts of Lix 984H extractant, 7 to 11 parts of kerosene, 1 to 3 parts of di-(2-ethylhexyl) phosphate, and 1 to 3 parts of bis(2,4,4-trimethylpentyl)phosphinic acid.

[0010] Preferably, during the extraction process, the first organic extractant and the second organic extractant have the same composition, and are composed of the following components in parts by weight: 3 parts of Lix 984H extractant, 9 parts of kerosene, 2 parts of di-(2-ethylhexyl) phosphate, and 2 parts of bis(2,4,4-trimethylpentyl)phosphinic acid.

[0011] Preferably, during the extraction process, the first organic extractant and the second organic extractant have the same composition, and are composed of the following components in parts by weight: 5 parts of Lix 984H extractant, 7 parts of kerosene, 1 part of di-(2-ethylhexyl) phosphate, and 1 part of bis(2,4,4-trimethylpentyl)phosphinic acid.

[0012] Preferably, during the extraction process, the first organic extractant and the second organic extractant have the same composition, and are composed of the following components in parts by weight: 1 part of Lix 984H extractant, 11 parts of kerosene, 3 parts of di-(2-ethylhexyl) phosphate, and 3 parts of bis(2,4,4-trimethylpentyl)phosphinic acid.

[0013] Preferably, during the extraction process, the pH regulator is a citric acid buffer. The use of a citric acid buffer can optimize the extraction performance of the Lix 984H extractant and improve the extraction efficiency of copper ions.

[0014] Preferably, during the extraction process, the pretreated rinsing wastewater and the first organic extractant are mixed and stirred for 3 to 11 minutes and allowed to stand for 5 to 15 minutes.

[0015] Preferably, during the extraction process, the first raffinate and the second organic extractant are mixed and stirred for 3 to 11 minutes, and the standing time is 5 to 15 minutes.

[0016] Preferably, during the stripping process, the concentration of the sulfuric acid solution is 10 to 30 wt %.

[0017] Preferably, during the stripping process, the concentration of the sulfuric acid solution is 20 wt %.

[0018] The beneficial effects are as follows: the first organic extractant and the second organic extractant of the present application use Lix 984H extractant as the main copper extraction component, the Lix 984H extractant can form a copper complex with copper ions, kerosene is used to adjust the viscosity and density of the Lix 984H extractant, and the addition of kerosene can also prevent emulsification during the extraction process, ensure that the extractant and the aqueous phase have obvious stratification, and facilitate subsequent separation operations. At the same time, the two components of di-(2-ethylhexyl) phosphate and di-(2,4,4-trimethylpentyl) phosphinate are added because they contain phosphoryl groups and hydrophobic long-chain alkyl groups respectively, so they can coordinate with copper ions and cooperate with the Lix 984H extractant to form a more stable copper-extractant complex, which works together to improve the extraction efficiency of copper ions; and the present application also adjusts the pH value range to a suitable range according to the type of organic extractant to avoid too low or too high pH value affecting the extraction effect or causing other metal ions to be co-extracted, thereby improving the overall recovery rate and quality of copper;

[0019] The copper complex is obtained through the above extraction process, and then back-extracted with a sulfuric acid solution, so that copper can be effectively recovered, and the extractant can also be regenerated and reused; a two-stage extraction system is used to maximize the recovery of copper ions, reduce the heavy metal content in wastewater, and reduce the impact on the environment; the first copper-poor organic phase is combined with the second copper-poor organic phase, and then a new first organic extractant is added to continue to repeat the extraction steps, thereby realizing the recycling of the organic extractant and reducing the consumption of chemical reagents and waste emissions;

[0020] 1 to 5 parts of pre-treated rinse wastewater are mixed with 1 part of the first organic extractant in parts by weight to ensure the effective utilization rate of the extractant and the maximum extraction rate of copper ions; a pH regulator is added to the first copper-depleted raffinate to adjust the pH to 2 to 3, and then a secondary extraction is performed to further improve the recovery rate of copper ions; sulfuric acid solution is used to effectively recover copper sulfate during the back extraction process, and cathode copper is recovered by electrolytic deposition in an electrolytic cell. The entire process is efficient and stable, and can continuously produce high-quality copper products;

[0021] In summary, the copper recovery method of rinsing water after copper etching provided by the present application can more fully and efficiently transfer copper ions from large-scale low-concentration rinsing wastewater to organic extractants compared to single-stage extraction or simple chemical precipitation, electrolysis, ion exchange and adsorption methods, and the copper extraction is more complete and the copper extraction yield is high; and the organic extractant can be recycled to achieve the purpose of reducing costs. After extraction and back extraction, copper is effectively enriched, and combined with electrolysis, high-purity copper can be quickly obtained. The entire process is efficient and environmentally friendly. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can understand the present invention more clearly.

[0023] The following embodiments are only used to illustrate the present invention, but are not limited to the scope of the present invention. Based on the specific embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work belong to the protection scope of the present invention.

[0024] In the examples of the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art; in the examples of the present invention, unless otherwise specified, the technical means used are conventional means well known to those skilled in the art.

[0025] Source of raw materials:

[0026] Rinsing wastewater is collected from Guangdong Meizhou Longyu Electronic Technology Co., Ltd. by rinsing etched circuit boards with clean water;

[0027] Lix 984H extractant was purchased from Wuhan Jushun Chemical Co., Ltd.;

[0028] Kerosene was purchased from Wuhan Jiyesheng Chemical Co., Ltd.;

[0029] Di-(2-ethylhexyl) phosphate, purchased from Jiangsu Pulex Biotechnology Co., Ltd.;

[0030] Bis(2,4,4-trimethylpentyl)phosphinic acid was purchased from Zhongshan Dixin Chemical Co., Ltd.

[0031] Concentrated sulfuric acid was purchased from Guangdong Qiming Chemical Technology Co., Ltd.;

[0032] Titanium-based lead dioxide was purchased from Xi'an Aierdi Environmental Protection Technology Co., Ltd.;

[0033] The remaining reagents and equipment are commercially available.

[0034] Example 1

[0035] This embodiment provides an efficient and environmentally friendly method for recovering copper from rinse water after copper etching, comprising:

[0036] Pretreatment of rinsing wastewater: After rinsing the etched circuit board with clean water, the rinsing wastewater is collected into a storage tank, and then filtered and removed using activated carbon and polyvinylidene fluoride membranes to obtain pretreated rinsing wastewater;

[0037] Extraction: According to the weight ratio, 1 part of the pre-treated rinsing wastewater and 1 part of the first organic extractant were mixed and stirred at a speed of 500r / min for 3min, and allowed to stand for 5min to extract the copper in the pre-treated rinsing wastewater to obtain a first copper-rich organic phase and a first copper-poor raffinate, and a pH regulator was added to the first copper-poor raffinate to adjust the pH of the first copper-poor raffinate to 2. The pH regulator was a citric acid buffer, and then 1 part of the second organic extractant was added to every 5 parts of the first copper-poor raffinate, and the mixture was stirred at a speed of 500r / min for 3min, and allowed to stand for 5min for secondary extraction to obtain a second copper-rich organic phase and a second copper-poor raffinate (copper ion content 12.7mg / L), and the second copper-poor raffinate was discharged to the comprehensive sewage station for treatment; wherein, the first organic extractant and the second organic extractant have the same composition, both consisting of 1 part of Lix 984H extractant, 11 parts of kerosene, 3 parts of di-(2-ethylhexyl) phosphate, and 3 parts of bis(2,4,4-trimethylpentyl)phosphinic acid;

[0038] Stripping: According to the weight ratio, 1 part of 10wt% sulfuric acid solution is added to 5 parts of the second copper-rich organic phase for mixed stripping to obtain a copper sulfate solution and a first copper-poor organic phase (copper ion content is 13.4mg / L), and the copper sulfate solution is electrolytically deposited in an electrolytic cell to recover cathode copper, wherein the anode of the electrolytic cell is titanium-based lead dioxide plated, and the cathode is a copper mother sheet. The copper sulfate solution after electrolysis (copper ion content is 5.5g / L) is called a copper-poor electrolyte, sulfuric acid solution is added to the copper-poor electrolyte, and then mixed with the first copper-rich organic phase for stripping to obtain a copper sulfate solution and a second copper-poor organic phase, and the copper sulfate solution is continuously electrolyzed to recover cathode copper, and the first copper-poor organic phase is combined with the second copper-poor organic phase, and then a new first organic extractant is added to continue to repeat the extraction steps to extract new pre-treated rinse wastewater.

[0039] Example 2

[0040] This embodiment provides an efficient and environmentally friendly method for recovering copper from rinse water after copper etching, comprising:

[0041] Pretreatment of rinsing wastewater: After the etched circuit board is rinsed with clean water, the rinsing wastewater is collected into a storage tank, and then filtered and removed using activated carbon and polyvinylidene fluoride membranes in turn to obtain pretreated rinsing wastewater;

[0042] Extraction: According to the weight ratio, 3 parts of pre-treated rinsing wastewater and 1 part of the first organic extractant are mixed and stirred at a speed of 1000r / min for 7min, and allowed to stand for 10min to extract the copper in the pre-treated rinsing wastewater to obtain a first copper-rich organic phase and a first copper-poor raffinate, and a pH regulator is added to the first copper-poor raffinate to adjust the pH of the first copper-poor raffinate to 3. The pH regulator is a citric acid buffer, and then 1 part of the second organic extractant is added to every 7 parts of the first copper-poor raffinate, and the mixture is stirred at a speed of 1000r / min for 7min, and allowed to stand for 10min for secondary extraction to obtain a second copper-rich organic phase and a second copper-poor raffinate (copper ion content is less than 10.2mg / L), and the second copper-poor raffinate is discharged to the comprehensive sewage station for treatment; wherein, the first organic extractant and the second organic extractant have the same composition, both consisting of 3 parts of Lix 984H extractant, 9 parts of kerosene, 2 parts of di-(2-ethylhexyl) phosphate, and 2 parts of bis(2,4,4-trimethylpentyl)phosphinic acid;

[0043] Stripping: According to the weight ratio, 1 part of 20wt% sulfuric acid solution is added to every 7 parts of the second copper-rich organic phase for mixed stripping to obtain a copper sulfate solution and a first copper-poor organic phase (copper ion content is 11.8mg / L), and the copper sulfate solution is electrolytically deposited in an electrolytic cell to recover cathode copper, wherein the anode of the electrolytic cell is titanium-based lead dioxide plated, and the cathode is a copper mother sheet. The copper sulfate solution after electrolysis (copper ion content is 5.1g / L) is called a copper-poor electrolyte, sulfuric acid solution is added to the copper-poor electrolyte, and then mixed with the first copper-rich organic phase for stripping to obtain a copper sulfate solution and a second copper-poor organic phase, and the copper sulfate solution is continuously electrolyzed to recover cathode copper, and the first copper-poor organic phase is combined with the second copper-poor organic phase, and then a new first organic extractant is added to continue to repeat the extraction steps to extract new pre-treated rinse wastewater.

[0044] Example 3

[0045] This embodiment provides an efficient and environmentally friendly method for recovering copper from rinse water after copper etching, comprising:

[0046] Pretreatment of rinsing wastewater: After the etched circuit board is rinsed with clean water, the rinsing wastewater is collected into a storage tank, and then filtered and removed using activated carbon and polyvinylidene fluoride membranes in turn to obtain pretreated rinsing wastewater;

[0047] Extraction: According to the weight ratio, 5 parts of pre-treated rinsing wastewater and 1 part of the first organic extractant were mixed and stirred at a speed of 1500r / min for 11min, and allowed to stand for 15min to extract the copper in the pre-treated rinsing wastewater to obtain a first copper-rich organic phase and a first copper-poor raffinate, and a pH regulator was added to the first copper-poor raffinate to adjust the pH of the first copper-poor raffinate to 2. The pH regulator was a citric acid buffer, and then 1 part of the second organic extractant was added to every 9 parts of the first copper-poor raffinate, and the mixture was stirred at a speed of 1500r / min for 11min, and allowed to stand for 15min for secondary extraction to obtain a second copper-rich organic phase and a second copper-poor raffinate (copper ion content of 9.8mg / L), and the second copper-poor raffinate was discharged to the comprehensive sewage station for treatment; wherein, the first organic extractant and the second organic extractant have the same composition, both consisting of 5 parts of Lix 984H extractant, 7 parts of kerosene, 1 part of di-(2-ethylhexyl) phosphate, and 1 part of bis(2,4,4-trimethylpentyl)phosphinic acid;

[0048] Stripping: According to the weight ratio, 1 part of 30wt% sulfuric acid solution is added to every 9 parts of the second copper-rich organic phase for mixed stripping to obtain a copper sulfate solution and a first copper-poor organic phase (copper ion content is less than 11.1mg / L), and the copper sulfate solution is electrolytically deposited in an electrolytic cell to recover cathode copper, wherein the anode of the electrolytic cell is titanium-based lead dioxide plated, and the cathode is a copper mother sheet. The copper sulfate solution after electrolysis (copper ion content is 4.8g / L) is called a copper-poor electrolyte, sulfuric acid solution is added to the copper-poor electrolyte, and then mixed with the first copper-rich organic phase for stripping to obtain a copper sulfate solution and a second copper-poor organic phase, and the copper sulfate solution is continuously electrolyzed to recover cathode copper, and the first copper-poor organic phase is combined with the second copper-poor organic phase, and then a new first organic extractant is added to continue to repeat the extraction steps to extract new pre-treated rinse wastewater.

[0049] Comparative Example 1

[0050] This comparative example provides an efficient and environmentally friendly method for recovering copper from rinse water after copper etching, comprising:

[0051] Pretreatment of rinsing wastewater: After the etched circuit board is rinsed with clean water, the rinsing wastewater is collected into a storage tank, and then filtered and removed using activated carbon and polyvinylidene fluoride membranes in turn to obtain pretreated rinsing wastewater;

[0052] Extraction: According to the weight ratio, 5 parts of pre-treated rinsing wastewater and 1 part of the first organic extractant were mixed and stirred at a speed of 1500r / min for 11min, and allowed to stand for 15min to extract the copper in the pre-treated rinsing wastewater to obtain a first copper-rich organic phase and a first copper-poor raffinate, and a pH regulator was added to the first copper-poor raffinate to adjust the pH of the first copper-poor raffinate to 2. The pH regulator was selected from citric acid buffer, and then 1 part of the second organic extractant was added to every 9 parts of the first copper-poor raffinate, and the mixture was stirred at a speed of 1500r / min for 11min, and allowed to stand for 15min for secondary extraction to obtain a second copper-rich organic phase and a second copper-poor raffinate (copper ion content of 19.8mg / L), and the second copper-poor raffinate was discharged to the comprehensive sewage station for treatment; wherein, the first organic extractant and the second organic extractant have the same composition, and are both obtained by mixing 5 parts of Lix 984H extractant and 7 parts of kerosene;

[0053] Stripping: According to the weight ratio, 1 part of 5wt% sulfuric acid solution is added to every 11 parts of the second copper-rich organic phase for mixed stripping to obtain a copper sulfate solution and a first copper-poor organic phase (copper ion content is 18.7mg / L), and the copper sulfate solution is electrolytically deposited in an electrolytic cell to recover cathode copper, wherein the anode of the electrolytic cell is titanium-based lead dioxide plated, and the cathode is a copper mother sheet. The copper sulfate solution after electrolysis (copper ion content is 4.9g / L) is called a copper-poor electrolyte, sulfuric acid solution is added to the copper-poor electrolyte, and then mixed with the first copper-rich organic phase for stripping to obtain a copper sulfate solution and a second copper-poor organic phase, and the copper sulfate solution is continuously electrolyzed to recover cathode copper, and the first copper-poor organic phase is combined with the second copper-poor organic phase, and then a new first organic extractant is added to continue to repeat the extraction steps to extract new pre-treated rinse wastewater.

[0054] Comparative Example 2

[0055] This comparative example provides an efficient and environmentally friendly method for recovering copper from rinse water after copper etching, comprising:

[0056] Pretreatment of rinsing wastewater: After the etched circuit board is rinsed with clean water, the rinsing wastewater is collected into a storage tank, and then filtered and removed using activated carbon and polyvinylidene fluoride membranes in turn to obtain pretreated rinsing wastewater;

[0057] Extraction: According to the weight ratio, 5 parts of pre-treated rinsing wastewater and 1 part of the first organic extractant are mixed and stirred at a speed of 1500r / min for 11min, and allowed to stand for 15min to extract the copper in the pre-treated rinsing wastewater to obtain a first copper-rich organic phase and a first copper-poor raffinate, a pH regulator is added to the first copper-poor raffinate to adjust the pH of the first copper-poor raffinate to 1, and a 70wt% sulfuric acid solution is selected as the pH regulator, and then 1 part of the second organic extractant is added to every 9 parts of the first copper-poor raffinate, mixed and stirred at a speed of 1500r / min for 11min, and allowed to stand for 15min for secondary extraction to obtain a second copper-rich organic phase and a second copper-poor raffinate (copper ion content is 17.6mg / L), and the second copper-poor raffinate is discharged to a comprehensive sewage station for treatment; wherein, the first organic extractant and the second organic extractant have the same composition, and are both obtained by mixing 5 parts of Lix 984H extractant and 7 parts of kerosene;

[0058] Stripping: According to the weight ratio, 1 part of 70wt% sulfuric acid solution is added to every 9 parts of the second copper-rich organic phase for mixed stripping to obtain a copper sulfate solution and a first copper-poor organic phase (copper ion content is less than 15.7mg / L), and the copper sulfate solution is electrolytically deposited in an electrolytic cell to recover cathode copper, wherein the anode of the electrolytic cell is titanium-based lead dioxide plated, and the cathode is a copper mother sheet. The copper sulfate solution after electrolysis (copper ion content is 4.8g / L) is called a copper-poor electrolyte, sulfuric acid solution is added to the copper-poor electrolyte, and then mixed with the first copper-rich organic phase for stripping to obtain a copper sulfate solution and a second copper-poor organic phase, and the copper sulfate solution is continuously electrolyzed to recover cathode copper, and the first copper-poor organic phase is combined with the second copper-poor organic phase, and then a new first organic extractant is added to continue to repeat the extraction steps to extract new pre-treated rinse wastewater.

[0059] It can be seen from Examples 1 to 3 that, during the extraction process, the ratio of the pre-treated rinsing wastewater to the first organic extractant, the extraction speed, stirring time, standing time and pH value during the extraction process, the ratio of the first copper-poor raffinate to the second organic extractant, and the proportion of the components of the first organic extractant and the second organic extractant will have an important influence on the extraction yield of copper. In the stripping process, the ratio of the second copper-rich organic phase to the sulfuric acid solution and the concentration of the sulfuric acid solution will also affect the stripping yield of copper. From the three examples, Example 3 has the highest extraction yield of copper and the highest stripping yield of copper. Comparative Example 1 and By comparing Example 3, it can be found that when the composition of the first organic extractant and the second organic extractant is changed during the extraction process of Comparative Example 1, the extraction yield of copper will be reduced. In the stripping process, the ratio between the second copper-rich organic phase and the sulfuric acid solution and the concentration of the sulfuric acid solution are changed, and the stripping yield of copper will be reduced. By comparing Comparative Example 2 with Example 3, it can be found that when Comparative Example 2 is used in the extraction process, 70wt% sulfuric acid solution is used to replace the citric acid buffer as the pH regulator, and the pH of the first copper-depleted raffinate is adjusted to 1, the extraction yield of copper will be reduced. In the stripping process, the concentration of the stripping agent sulfuric acid solution is increased, and the stripping yield of copper is also reduced.

[0060] The above is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, 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

1. A method for recovering copper from rinsing water after copper etching, characterized in that: include: Pretreatment of rinsing wastewater: After rinsing the etched circuit board with clean water, collect the rinsing wastewater into a storage tank, filter and remove impurities, and obtain pretreated rinsing wastewater; Extraction: According to the weight ratio, 1 to 5 parts of the pre-treated rinsing wastewater are mixed with 1 part of the first organic extractant, stirred, and allowed to stand to extract the copper in the pre-treated rinsing wastewater to obtain a first copper-rich organic phase and a first copper-poor raffinate, a pH regulator is added to the first copper-poor raffinate to adjust the pH of the first copper-poor raffinate to 2 to 3, and then 1 part of the second organic extractant is added to every 5 to 9 parts of the first copper-poor raffinate, mixed and stirred, and allowed to stand for secondary extraction to obtain a second copper-rich organic phase and a second copper-poor raffinate (copper ion content is less than 20 mg / L), and the second copper-poor raffinate is discharged to a comprehensive sewage station for treatment; wherein the first organic extractant and the second organic extractant have the same composition, and are obtained by mixing Lix 984H extractant, kerosene, di-(2-ethylhexyl) phosphate and bis(2,4,4-trimethylpentyl)phosphinic acid; Stripping: according to the weight ratio, 1 part of sulfuric acid solution is added to every 5 to 9 parts of the second copper-rich organic phase for mixed stripping to obtain a copper sulfate solution and a first copper-poor organic phase (copper ion content is less than 20 mg / L), the copper sulfate solution is electrolytically deposited in an electrolytic cell to recover cathode copper, wherein the anode of the electrolytic cell is titanium-based lead dioxide plated, and the cathode is a copper mother sheet, the copper sulfate solution after electrolysis (copper ion content is less than 10 g / L) is called a copper-poor electrolyte, sulfuric acid solution is added to the copper-poor electrolyte, and then mixed with the first copper-rich organic phase for stripping to obtain a copper sulfate solution and a second copper-poor organic phase, the copper sulfate solution is continuously electrolyzed to recover cathode copper, the first copper-poor organic phase is combined with the second copper-poor organic phase, and then a new first organic extractant is added to continue to repeat the extraction step to extract new pre-treated rinse wastewater.

2. The method for recovering copper from rinsing water after etching copper according to claim 1, characterized in that: In the extraction process, the first organic extractant and the second organic extractant have the same composition, and are composed of the following components in parts by weight: 1 to 5 parts of Lix 984H extractant, 7 to 11 parts of kerosene, 1 to 3 parts of di-(2-ethylhexyl) phosphate, and 1 to 3 parts of bis(2,4,4-trimethylpentyl) phosphinic acid.

3. The method for recovering copper by rinsing water after etching copper according to claim 1, characterized in that: In the extraction process, the first organic extractant and the second organic extractant have the same composition, and are composed of the following components in parts by weight: 3 parts of Lix 984H extractant, 9 parts of kerosene, 2 parts of di-(2-ethylhexyl) phosphate, and 2 parts of bis(2,4,4-trimethylpentyl) phosphinic acid.

4. The method for recovering copper from rinsing water after etching copper according to claim 1, characterized in that: In the extraction process, the first organic extractant and the second organic extractant have the same composition, and are composed of the following components in parts by weight: 5 parts of Lix 984H extractant, 7 parts of kerosene, 1 part of di-(2-ethylhexyl) phosphate, and 1 part of di(2,4,4-trimethylpentyl) phosphinic acid.

5. The method for recovering copper from rinsing water after etching copper according to claim 1, characterized in that: In the extraction process, the first organic extractant and the second organic extractant have the same composition, and are composed of the following components in parts by weight: 1 part of Lix 984H extractant, 11 parts of kerosene, 3 parts of di-(2-ethylhexyl) phosphate, and 3 parts of bis(2,4,4-trimethylpentyl) phosphinic acid.

6. The method for recovering copper from rinsing water after etching copper according to claim 1, characterized in that: In the extraction process, the pH regulator is selected from citric acid buffer. The pH value range needs to be adjusted to a suitable range according to the type of organic extractant to avoid too low or too high pH values ​​that affect the extraction effect or cause co-extraction of other metal ions. The selection of citric acid buffer can optimize the extraction performance of the Lix 984H extractant and improve the extraction rate of copper ions to a certain extent.

7. The method for recovering copper from rinsing water after etching copper according to claim 1, characterized in that: During the extraction process, the pretreated rinsing wastewater and the first organic extractant are mixed and stirred for 3 to 11 minutes and allowed to stand for 5 to 15 minutes.

8. The method for recovering copper from rinsing water after copper etching according to claim 1, characterized in that: During the extraction process, the first raffinate and the second organic extractant are mixed and stirred for 3 to 11 minutes, and the standing time is 5 to 15 minutes.

9. The method for recovering copper from rinsing water after copper etching according to claim 1, characterized in that: During the stripping process, the concentration of the sulfuric acid solution is 10-30 wt %.

10. The method for recovering copper from rinsing water after etching copper according to claim 1, characterized in that: During the stripping process, the concentration of the sulfuric acid solution was 20 wt %.