Method for deeply treating copper-containing wastewater of electrolytic copper foil

Abstract

The invention provides a method for deeply treating copper-containing wastewater of an electrolytic copper foil, belongs to the technical field of copper-containing wastewater recovery in production of the electrolytic copper foil, and solves the problems that the copper-containing wastewater of the electrolytic copper foil cannot be effectively treated, the recovery rate is low and impurities exist in the traditional treatment method. The method comprises the following steps: feeding copper-containing leaching water generated in electrolytic copper foil production into first-stage reverse osmosis equipment for concentration, and separating the separated reclaimed water into fresh water through second-stage reverse osmosis equipment; feeding a concentrated solution produced by the concentrated water reverse osmosis equipment into ultrahigh-pressure reverse osmosis equipment for concentration; reclaimed water from the ultrahigh-pressure reverse osmosis equipment is returned to the first-stage reverse osmosis equipment for circular treatment. According to the method, the high-pollution-resistance reverse osmosis membrane separation technology is adopted, copper in the copper-containing waste water can be recycled, the cost is reduced, meanwhile, discharge of the copper-containing waste liquid is eradicated, waste of water resources is reduced, and the environment is not polluted.

Description

Technical Field

[0001] This invention belongs to the technical field of copper-containing wastewater recovery in the production of electrolytic copper foil, and specifically relates to a method for deep treatment of copper-containing wastewater from electrolytic copper foil production. Background Technology

[0002] Electrolytic copper foil, due to its superior ductility, low roughness, and high density, is widely used as a fundamental material in the electronics and information industry. During the copper foil production process, copper is deposited from a copper sulfate electrolyte under the action of direct current to form raw foil. This raw foil requires surface treatment to achieve the different properties required by customers.

[0003] During the production and surface treatment of foil, a pure water rinsing process is required to remove the electrolyte attached to the surface. Therefore, a large amount of acidic copper-containing rinsing water is generated throughout the production process. This water contains Cu. 2+ And sulfuric acid. Cu 2+ The concentration range is 0.1-2 g / L, and the sulfuric acid concentration range is 0.1-5 g / L.

[0004] Before the invention of this invention, simple concentration was mainly achieved through a two-stage reverse osmosis membrane separation technology: copper-containing wash water was first collected in a storage tank, then concentrated to about 10 g / L through a two-stage reverse osmosis membrane before being used in the copper foil production system. During the two-stage reverse osmosis membrane treatment, sodium hydroxide was added to adjust the pH, a flocculant was added to increase the concentration, and a scale inhibitor was added to break down the molecular chains of the solution.

[0005] This approach has the following drawbacks: 1. In the daily production process of electrolytic copper foil, the amount of copper-containing wastewater is large, and the amount of concentrated liquid produced is also large. The two-stage reverse osmosis membrane cannot treat the waste liquid in time, which also causes a lot of water waste and increases production costs.

[0006] 2. The copper content of the concentrate produced by the two-stage concentration is low. The copper foil system has a low copper content and is not conducive to the production process of electroplating grade copper sulfate. At the same time, the two-stage reverse osmosis membrane cannot achieve repeated reuse and concentration of the concentrate.

[0007] 3. The addition of other additives during the processing results in the presence of other impurities in the final concentrate, making it impossible to reach the grade of electroplating-grade copper sulfate. Summary of the Invention

[0008] The purpose of this invention is to provide a method for deep treatment of copper-containing wastewater from electrolytic copper foil, in order to solve the problems of traditional methods for treating copper-containing wastewater from electrolytic copper foil, such as ineffective wastewater treatment, low recovery rate, and the presence of impurities.

[0009] The technical solution of this invention is: a method for deep treatment of copper-containing wastewater from electrolytic copper foil, comprising the following steps: Step 1: The copper-containing rinsing water generated during the production of electrolytic copper foil is transported to the rinsing water collection tank and then sent to the first-stage reverse osmosis equipment to concentrate the copper-containing rinsing water. The water separated by the first-stage reverse osmosis equipment is then separated into fresh water by the second-stage reverse osmosis equipment. The pure water after treatment by the treatment system can be used for various water washing operations in the electrolytic copper foil production system. A portion of the concentrate from the secondary reverse osmosis unit is returned to the primary reverse osmosis unit for reuse. Step 2: Part of the concentrate from the first-stage reverse osmosis unit is concentrated in the concentrate reverse osmosis unit, while the other part is returned to the first-stage reverse osmosis unit for reuse. Step 3: The concentrate produced by the concentrated water reverse osmosis equipment is sent to the ultra-high pressure reverse osmosis equipment for concentration. The final concentrated and separated concentrate can be used in the copper sulfate production system to produce electroplating grade copper sulfate. Step 4: The treated water from the ultra-high pressure reverse osmosis equipment is returned to the primary reverse osmosis equipment for recycling.

[0010] As a further improvement of the present invention, in step one, the primary reverse osmosis equipment concentrates the copper-containing rinse water, wherein the copper content is concentrated by 2-5 times.

[0011] As a further improvement of the present invention, in step one, the acidic wastewater containing copper-containing rinsing water contains Cu. 2+ And acid, copper-containing wastewater Cu 2+ The concentration range is 0.1-2 g / L, and the sulfuric acid concentration range is 0.1-5 g / L.

[0012] As a further improvement of the present invention, in step one, the Cu in the feed water of the primary reverse osmosis equipment 2+ The concentration should be controlled within 5 g / L, and the sulfuric acid concentration range should be within 5 g / L.

[0013] As a further improvement of the present invention, in step one, after the copper-containing scrubbing water is concentrated in the primary reverse osmosis equipment, the concentrated solution Cu 2+ The concentration is 0.2-10 g / L.

[0014] As a further improvement of the present invention, in step three, the wastewater is concentrated in the concentrated water reverse osmosis equipment, and the concentrated liquid Cu 2+ The concentration is 1-20 g / L; wastewater is concentrated in ultra-high pressure reverse osmosis equipment, and the concentrate contains Cu. 2+ The concentration is 10-30 g / L.

[0015] As a further improvement of the present invention, in step three, the Cu used in the copper sulfate production system to produce the concentrated solution of electroplating-grade copper sulfate... 2+ The concentration is 20-30 g / L, and the sulfuric acid concentration is 20-30 g / L.

[0016] The beneficial effects of this invention are as follows: In this method, the water reuse rate in the two-stage reverse osmosis equipment can reach 80-85%. After two-stage desalination and two-stage concentration separation, the wastewater is used normally, and no sewage is discharged. It has produced significant effects in terms of production, environmental protection, and energy conservation.

[0017] This method enables copper recovery, reducing costs and eliminating the discharge of heavy metal wastewater. It achieves a high concentration of copper ions, providing stable technical conditions for the production of electroplating-grade copper sulfate solution through deep copper extraction. No additives are used throughout the entire process, ensuring the purity of the concentrate and enabling comprehensive utilization of wastewater, thus creating economic benefits for enterprises. Attached Figure Description

[0018] Figure 1 This is a flowchart of the processing method in this invention; Figure 2 This is a schematic diagram of the ultra-high pressure reverse osmosis equipment treatment method in this invention.

[0019] In the diagram: 1- Primary reverse osmosis equipment; 2- Concentrate reverse osmosis equipment; 3- Ultra-high pressure reverse osmosis equipment; 4- Copper sulfate production system; 5- Secondary reverse osmosis equipment; 6- Treatment system; 7- Electrolytic copper foil production system. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Example 1 Step 1: The copper-containing rinsing water generated during the electrolytic copper foil production is transported to the rinsing water collection tank. This acidic wastewater contains Cu. 2+ And acid, copper-containing wastewater Cu 2+ The concentration range is 0.1 g / L, and the sulfuric acid concentration range is 0.1 g / L. Then it is sent to the first-stage reverse osmosis unit 1 to concentrate the copper-containing rinse water, concentrating the copper content by 2 times. The Cu in the feed water of the first-stage reverse osmosis unit 1... 2+ The concentration is controlled at 5 g / L, and the sulfuric acid concentration range is 5 g / L. The treated water separated by the first-stage reverse osmosis unit 1 is then separated into fresh water by the second-stage reverse osmosis unit 5. The pure water, after treatment by the treatment system 6, can be used for various washing operations in the electrolytic copper foil production system 7. After concentrating the copper-containing rinsing water in the first-stage reverse osmosis unit 1, the concentrated solution contains Cu... 2+ The concentration is 0.2 g / L; A portion of the concentrate from the secondary reverse osmosis unit 5 is returned to the primary reverse osmosis unit 1 for reuse. Step 2: Part of the concentrate from the first-stage reverse osmosis unit 1 is concentrated in the concentrate reverse osmosis unit 2, and the other part is returned to the first-stage reverse osmosis unit 1 for reuse. Step 3: The concentrate produced by the concentrated water reverse osmosis unit 2 is sent to the ultra-high pressure reverse osmosis unit 5 for further concentration. The final concentrated solution can be used in the copper sulfate production system 4 to produce electroplating-grade copper sulfate. The wastewater is concentrated in the concentrated water reverse osmosis unit 2, and the concentrated solution contains Cu... 2+ The concentration is 1 g / L; the wastewater is concentrated in ultra-high pressure reverse osmosis equipment 3, and the concentrate is Cu 2+ The concentration is 10 g / L. This Cu is used in the concentrated solution for producing electroplating-grade copper sulfate in copper sulfate production system 4. 2+ The concentration is 20 g / L, and the sulfuric acid concentration is 20 g / L.

[0022] Step 4: The treated water from the ultra-high pressure reverse osmosis unit 3 is returned to the first-stage reverse osmosis unit 1 for recycling.

[0023] Example 2 Step 1: The copper-containing rinsing water generated during the electrolytic copper foil production is transported to the rinsing water collection tank. This acidic wastewater contains Cu. 2+ And acid, copper-containing wastewater Cu 2+ The concentration range is 1 g / L, and the sulfuric acid concentration range is 2.5 g / L. Then it is sent to the first-stage reverse osmosis unit 1 to concentrate the copper-containing rinse water, concentrating the copper content by 3 times. The Cu in the feed water of the first-stage reverse osmosis unit 1... 2+ The concentration is controlled at 4.5 g / L, and the sulfuric acid concentration range is 4.5 g / L. The treated water separated by the first-stage reverse osmosis unit 1 is then separated into fresh water by the second-stage reverse osmosis unit 5. The pure water, after treatment by the treatment system 6, can be used for various washing operations in the electrolytic copper foil production system 7. The copper-containing rinsing water in the first-stage reverse osmosis unit 1 is concentrated to obtain Cu... 2+ The concentration is 5 g / L; A portion of the concentrate from the secondary reverse osmosis unit 5 is returned to the primary reverse osmosis unit 1 for reuse. Step 2: Part of the concentrate from the first-stage reverse osmosis unit 1 is concentrated in the concentrate reverse osmosis unit 2, and the other part is returned to the first-stage reverse osmosis unit 1 for reuse. Step 3: The concentrate produced by the concentrated water reverse osmosis unit 2 is sent to the ultra-high pressure reverse osmosis unit 5 for further concentration. The final concentrated solution can be used in the copper sulfate production system 4 to produce electroplating-grade copper sulfate. The wastewater is concentrated in the concentrated water reverse osmosis unit 2, and the concentrated solution contains Cu... 2+ The concentration is 10 g / L; the wastewater is concentrated in ultra-high pressure reverse osmosis equipment 3, and the concentrate is Cu 2+The concentration is 15 g / L. This Cu is used in the concentrated solution for producing electroplating-grade copper sulfate in copper sulfate production system 4. 2+ The concentration is 25 g / L, and the sulfuric acid concentration is 25 g / L.

[0024] Step 4: The treated water from the ultra-high pressure reverse osmosis unit 3 is returned to the first-stage reverse osmosis unit 1 for recycling.

[0025] Example 3 Step 1: The copper-containing rinsing water generated during the electrolytic copper foil production is transported to the rinsing water collection tank. This acidic wastewater contains Cu. 2+ And acid, copper-containing wastewater Cu 2+ The concentration range is 2 g / L, and the sulfuric acid concentration range is 5 g / L. Then it is sent to the first-stage reverse osmosis unit 1 to concentrate the copper-containing rinse water, concentrating the copper content by 5 times. The Cu in the feed water of the first-stage reverse osmosis unit 1... 2+ The concentration is controlled at 4 g / L, and the sulfuric acid concentration range is 4 g / L. The treated water separated by the first-stage reverse osmosis unit 1 is then separated into fresh water by the second-stage reverse osmosis unit 5. The pure water, after treatment by the treatment system 6, can be used for various washing operations in the electrolytic copper foil production system 7. The copper-containing rinsing water in the first-stage reverse osmosis unit 1 is concentrated to produce Cu... 2+ The concentration is 10 g / L; A portion of the concentrate from the secondary reverse osmosis unit 5 is returned to the primary reverse osmosis unit 1 for reuse. Step 2: Part of the concentrate from the first-stage reverse osmosis unit 1 is concentrated in the concentrate reverse osmosis unit 2, and the other part is returned to the first-stage reverse osmosis unit 1 for reuse. Step 3: The concentrate produced by the concentrated water reverse osmosis unit 2 is sent to the ultra-high pressure reverse osmosis unit 5 for further concentration. The final concentrated solution can be used in the copper sulfate production system 4 to produce electroplating-grade copper sulfate. The wastewater is concentrated in the concentrated water reverse osmosis unit 2, and the concentrated solution contains Cu... 2+ The concentration is 20 g / L; the wastewater is concentrated in ultra-high pressure reverse osmosis equipment 3, and the concentrate is Cu 2+ The concentration is 30 g / L. This Cu is used in the concentrated solution for producing electroplating-grade copper sulfate in copper sulfate production system 4. 2+ The concentration is 30 g / L, and the sulfuric acid concentration is 30 g / L.

[0026] Step 4: The treated water from the ultra-high pressure reverse osmosis unit 3 is returned to the first-stage reverse osmosis unit 1 for recycling.

[0027] Ultra-high pressure reverse osmosis equipment 3 utilizes a high-pressure pump to apply pressure, and under high pressure, Cu... 2+The invention separates sulfuric acid and water using a reverse osmosis membrane, enabling the separate recycling of water and copper sulfate. This technology can separate over 98% of the water from copper-containing wastewater, leaving a usable high-concentration copper and acid solution (copper sulfate). After two stages of desalination and two stages of concentration separation, the wastewater is reused normally, with no wastewater discharge. This has produced significant effects on production, environmental protection, and energy conservation.

Claims

1. A method for deep treatment of copper-containing wastewater from electrolytic copper foil, characterized in that: Includes the following steps: Step 1: The copper-containing rinsing water generated in the production of electrolytic copper foil is transported to the rinsing water collection tank and then sent to the first-stage reverse osmosis equipment (1) to concentrate the copper-containing rinsing water. The water separated by the first-stage reverse osmosis equipment (1) is then separated into fresh water by the second-stage reverse osmosis equipment (5). The pure water after treatment by the treatment system (6) can be used for various water washing operations in the electrolytic copper foil production system (7). A portion of the concentrate from the secondary reverse osmosis unit (5) is returned to the primary reverse osmosis unit (1) for reuse; Step 2: Part of the concentrate from the first-stage reverse osmosis unit (1) is concentrated in the concentrated water reverse osmosis unit (2), and the other part is returned to the first-stage reverse osmosis unit (1) for reuse. Step 3: The concentrate produced by the concentrated water reverse osmosis equipment (2) is sent to the ultra-high pressure reverse osmosis equipment (5) for concentration. The concentrated and separated concentrate can be used in the copper sulfate production system (4) to produce electroplating grade copper sulfate. Step 4: The treated water from the ultra-high pressure reverse osmosis equipment (3) is returned to the first-stage reverse osmosis equipment (1) for recycling.

2. The method for deep treatment of copper-containing wastewater from electrolytic copper foil according to claim 1, characterized in that: In step one, the primary reverse osmosis equipment (1) concentrates the copper-containing scrubbing water, with the copper content concentrated by 2-5 times.

3. The method for deep treatment of copper-containing wastewater from electrolytic copper foil according to claim 1, characterized in that: In step one, the acidic wastewater containing copper-containing rinsing water contains Cu. 2+ And acid, copper-containing wastewater Cu 2+ The concentration range is 0.1-2 g / L, and the sulfuric acid concentration range is 0.1-5 g / L.

4. The method for deep treatment of copper-containing wastewater from electrolytic copper foil according to claim 1, characterized in that: In step one, the Cu inlet water of the primary reverse osmosis unit (1) 2+ The concentration should be controlled within 5 g / L, and the sulfuric acid concentration range should be within 5 g / L.

5. The method for deep treatment of copper-containing wastewater from electrolytic copper foil according to claim 1, characterized in that: In step one, after the copper-containing scrubbing water is concentrated in the primary reverse osmosis equipment (1), the concentrated solution Cu 2+ The concentration is 0.2-10 g / L.

6. The method for deep treatment of copper-containing wastewater from electrolytic copper foil according to claim 1, characterized in that: In step three, the wastewater is concentrated in the concentrated water reverse osmosis equipment (2), and the concentrated liquid Cu 2+ The concentration is 1-20 g / L; the wastewater is concentrated in the ultra-high pressure reverse osmosis equipment (3), and the concentrate Cu 2+ The concentration is 10-30 g / L.

7. The method for deep treatment of copper-containing wastewater from electrolytic copper foil according to claim 1, characterized in that: In step three, Cu is used in the concentrated solution for producing electroplating-grade copper sulfate in the copper sulfate production system (4). 2+ The concentration is 20-30 g / L, and the sulfuric acid concentration is 20-30 g / L.

Images