Water recovery system for copper foil manufacturing process
By using a two-stage pH adjustment and reverse osmosis membrane coupled process to treat copper foil manufacturing wastewater, the problem of heavy metal pollution was solved, achieving efficient heavy metal removal and resource recovery, and reducing environmental pollution and production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- KEJIN INT (XIAN) ENVIRONMENTAL TECH CO LTD
- Filing Date
- 2025-06-19
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technologies cannot effectively treat heavy metal ions in copper foil manufacturing wastewater, leading to environmental pollution and resource waste. Furthermore, traditional treatment methods are prone to causing secondary pollution.
The process employs a two-stage pH adjustment coupled with reverse osmosis membrane technology. Wastewater is pretreated in a primary pH adjustment reaction tank, particulate matter is removed using a precision filter tank, and reverse osmosis separation is performed using a membrane filtration device to generate purified water and heavy metal concentrate. Finally, the pH value of the purified water is adjusted in a secondary pH adjustment reaction tank for reuse.
It achieves deep removal and resource utilization of heavy metal wastewater, with high water reuse rate, low energy consumption, small equipment footprint, and reduced environmental pollution risk and production cost.
Smart Images
Figure CN224258453U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water recycling technology, and in particular to a water recycling system for copper foil manufacturing. Background Technology
[0002] Copper foil manufacturing wastewater comprises various wastewaters generated during the electrolytic copper foil production process. The main pollutants are heavy metal ions such as copper, zinc, nickel, and chromium. Direct discharge of these pollutants without effective treatment will cause severe and irreversible damage to the ecological environment. Heavy metal ions are highly toxic, difficult to degrade, and bioaccumulate. Once they enter water bodies, they rapidly disrupt the balance of aquatic ecosystems: copper ions inhibit algal photosynthesis, leading to a decrease in dissolved oxygen; zinc, nickel, and other metals are highly physiologically toxic to fish and benthic organisms, causing population decline and even local extinction; hexavalent chromium is a recognized potent carcinogen that can accumulate through the food chain, ultimately threatening human health. Furthermore, this type of wastewater is typically highly acidic (low pH) and highly saline, further exacerbating soil acidification, compaction, and groundwater salinization, damaging plant root development, and leading to severe degradation of land productivity. Long-term accumulation of heavy metal pollution not only renders receiving water bodies unable to self-purify, but also contaminates farmland crops through irrigation seepage, forming a three-dimensional pollution chain of "water-soil-food," posing a persistent threat to regional ecological security and public health. Although existing technologies such as chemical precipitation and membrane separation can partially remove heavy metals, incomplete treatment or improper sludge disposal can easily lead to secondary pollution. There is an urgent need to develop efficient, low-consumption, and resource-efficient water recycling systems to achieve near-zero wastewater discharge and closed-loop management of heavy metals. Utility Model Content
[0003] The technical problem to be solved by this utility model is to provide a copper foil manufacturing process water recycling system that removes heavy metal ions from wastewater and converts it into industrially usable concentrate and pure water, thereby effectively reducing pollution to the environment.
[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a copper foil process water recovery system, comprising: two pH adjustment reaction tanks, a precision filter tank, and a membrane filter device;
[0005] The two pH adjustment reaction tanks are a primary pH adjustment reaction tank and a secondary pH adjustment reaction tank, respectively.
[0006] The output end of the primary pH adjustment reaction tank is connected to the input end of the precision filter tank, the output end of the precision filter tank is connected to the input end of the membrane filtration device, and the output end of the membrane filtration device is connected to the input end of the secondary pH adjustment reaction tank.
[0007] The primary pH adjustment reaction tank is used to adjust the pH value of the wastewater to be treated by adding chemicals; the precision filter tank is used to remove particulate matter from the wastewater after pH adjustment; the membrane filtration device is used to concentrate heavy metal ions in the wastewater into a concentrate by reverse osmosis separation filtration to obtain purified water; the secondary pH adjustment reaction tank is used to adjust the pH value of the purified water by adding chemicals to obtain recycled water.
[0008] Furthermore, the filtration accuracy of the precision filter canister is 5 micrometers.
[0009] Furthermore, the pH adjustment reaction tank includes a tank body, a motor is installed inside the tank body, the output shaft of the motor is connected to a stirring paddle, and a dosing pump is installed at the top of the tank body.
[0010] Furthermore, the membrane filtration device includes a reverse osmosis membrane module, and the input end of the reverse osmosis membrane module is also connected to a high-pressure inlet pump.
[0011] Furthermore, the system also includes a concentrate storage device, the input end of which is connected to the output end of the membrane filtration device; the concentrate storage device is used to store the concentrate produced by the membrane filtration device.
[0012] Furthermore, the output end of the concentrated liquid storage device is connected to the first discharge delivery pump.
[0013] Furthermore, the system also includes a recycled water storage device, the input end of which is connected to the output end of the secondary pH adjustment reaction tank; the recycled water storage device is used to store the recycled water generated by the secondary pH adjustment reaction tank.
[0014] Furthermore, the output end of the recycled water storage device is connected to the second discharge pump.
[0015] This utility model has the following advantages compared with the prior art:
[0016] This invention provides a copper foil manufacturing process water recycling system that significantly improves the purification efficiency and resource recovery rate of heavy metal wastewater through a multi-stage collaborative treatment mechanism. Specifically:
[0017] 1. Deep removal of heavy metals and pollution blocking
[0018] The system employs a two-stage pH adjustment coupled with reverse osmosis membrane technology. The first-stage pH adjustment reaction tank, through acid-base neutralization pretreatment, effectively suppresses the risk of scaling in subsequent equipment due to the hydrolysis and precipitation of heavy metal ions. After suspended particles are intercepted by a precision filter tank (5-micron precision), the membrane filtration device, driven by a high-pressure pump, removes heavy metal ions (Cu) through reverse osmosis. 2+ Zn 2+ Ni2+ Cr 6+ (etc.) are separated from water at the molecular level, with a removal rate of over 99%, completely blocking their entry into the ecological environment and eliminating the basis for the formation of the "water-soil-food" three-dimensional pollution chain described in the background technology from the source.
[0019] 2. Closed-loop management of resource utilization
[0020] The reverse osmosis process simultaneously produces high-purity purified water and heavy metal concentrate: the purified water is precisely conditioned in a two-stage pH adjustment reaction tank to generate neutral reclaimed water, which can be directly used in production lines or cooling systems to achieve water resource recycling; the concentrate is directed to a storage device for centralized management, where the enriched heavy metals can be extracted and regenerated into industrial raw materials (such as electrolytic copper foil anode liquid), forming a closed loop of heavy metal resource recovery and harmless disposal, completely avoiding the risk of secondary pollution from sludge generated by traditional chemical precipitation methods.
[0021] 3. System stability and energy efficiency advantages
[0022] The precision filter tank effectively intercepts particulate matter, and the two-stage pH adjustment controls the tendency to scale, significantly reducing the frequency of reverse osmosis membrane fouling and extending the life of core components. The modular design (such as the integration of stirring motors and dosing pumps) ensures a uniform and efficient reaction process, increasing reagent utilization by more than 30%. Driven by a high-pressure pump, the reverse osmosis process reduces energy consumption by 40-60% compared to traditional technologies such as evaporation and concentration, and reduces the equipment footprint by 50%, meeting the compact requirements of industrial scenarios.
[0023] 4. Ecological and economic benefits
[0024] The system ultimately achieves near-zero wastewater discharge, reducing the discharge of tens of thousands of tons of acidic wastewater containing heavy metals annually, thus avoiding its photosynthetic inhibition, biological toxicity, and soil salinization damage to aquatic ecosystems. At the same time, the reuse of water to replace fresh water sources and the recovery of heavy metal resources directly reduce production costs, achieving a dual benefit of environmental governance and economic benefits.
[0025] In summary, this invention utilizes a reverse osmosis membrane to recycle wastewater from the copper foil manufacturing process, removing heavy metal ions from the wastewater and converting it into industrially usable concentrate and purified water. The recycled water is of good quality, the process is simple, energy consumption is low, and the equipment is simple, thereby effectively reducing pollution to the environment.
[0026] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of the overall structure of a copper foil manufacturing process water recycling system provided by this utility model.
[0028] Explanation of reference numerals in the attached figures:
[0029] 1. Primary pH adjustment reaction tank; 2. Precision filter tank; 3. Membrane filtration device; 4. Concentrate storage device; 5. Secondary pH adjustment reaction tank; 6. Reclaimed water storage device. Detailed Implementation
[0030] like Figure 1 As shown, the copper foil manufacturing process water recycling system provided by this utility model includes: two pH adjustment reaction tanks, a precision filter tank 2, and a membrane filter device 3;
[0031] The two pH adjustment reaction tanks are a primary pH adjustment reaction tank 1 and a secondary pH adjustment reaction tank 5, respectively.
[0032] The output end of the primary pH adjustment reaction tank 1 is connected to the input end of the precision filter tank 2, the output end of the precision filter tank 2 is connected to the input end of the membrane filter device 3, and the output end of the membrane filter device 3 is connected to the input end of the secondary pH adjustment reaction tank 5.
[0033] The primary pH adjustment reaction tank 1 is used to adjust the pH value of the wastewater to be treated by adding chemicals; the precision filter tank 2 is used to remove particulate matter from the wastewater after pH adjustment; the membrane filter device 3 is used to concentrate the heavy metal ions in the wastewater into a concentrate by reverse osmosis separation filtration to obtain purified water; the secondary pH adjustment reaction tank 5 is used to adjust the pH value of the purified water by adding chemicals to obtain recycled water.
[0034] In this invention, the components are connected sequentially via corrosion-resistant pipes.
[0035] Wastewater to be treated (containing Cu) 2+ 50-200 mg / L, Zn 2+ 20-80 mg / L, Ni 2+ 10-50 mg / L, Cr 6+ (5-30 mg / L, pH = 2-4) First, it enters the primary pH adjustment reaction tank 1. This tank is equipped with a stirring motor (speed 80-120 rpm) driving stainless steel blades. A top dosing pump quantitatively injects 10% NaOH solution to raise the pH to 6.5-7.5 to prevent heavy metal hydrolysis, precipitation, and scaling.
[0036] After neutralization, the wastewater flows into the precision filter tank 2, which has a built-in 5μm precision filter element (polypropylene material), which can intercept suspended particles ≥5μm (such as Fe(OH)3 colloids, CaSO4 crystals), and the effluent turbidity is ≤1NTU.
[0037] The pretreated water is pressurized by the inlet high-pressure pump (pressure 1.5-2.5MPa) and then enters the membrane filtration device 3. A polyamide composite reverse osmosis membrane (RO membrane) is used to separate purified water (water production rate 60-70%) and heavy metal concentrate (containing heavy metal ion concentration increased by 3-5 times) under molecular-level sieving.
[0038] In this invention, a two-stage pH adjustment system works synergistically to prevent scale buildup. The first-stage tank neutralizes strongly acidic wastewater, preventing calcium buildup. 2+ Mg 2+ Scaling occurs on the RO membrane surface; the secondary tank precisely adjusts the pH of the product water to meet reuse standards (such as GB / T 19923-2005 Industrial Circulating Cooling Water Quality).
[0039] The precision filter tank (2) has a filtration accuracy of 5 micrometers. It has a built-in 5μm precision filter element (polypropylene material), which can intercept suspended particles ≥5μm (such as Fe(OH)3 colloids, CaSO4 crystals), and the turbidity of the effluent is ≤1NTU.
[0040] The necessity of 5μm precision filtration in this invention: Experiments show (see Table 1) that when the filtration accuracy is >10μm, the RO membrane fouling cycle is shortened to 72 hours; using a 5μm filter element can extend it to 720 hours, and the membrane flux decay rate is <5% / month.
[0041] Table 1. Effects of different filtration precisions on RO membrane operation
[0042] Filtration accuracy (μm) Membrane fouling cycle (h) Membrane flux decline rate (%) / month 20 48 15.2 10 72 12.7 5 720 4.3
[0043] In addition, the pH adjustment reaction tank includes a tank body, a motor is installed inside the tank, the output shaft of the motor is connected to a stirring paddle, and a dosing pump is installed at the top of the tank body. The stirring paddle's function is to uniformly agitate the liquid after dosing, thereby increasing the reaction rate.
[0044] In this invention, the membrane filtration device 3 includes a reverse osmosis membrane module, and the input end of the reverse osmosis membrane module is also connected to a high-pressure inlet pump. A polyamide composite reverse osmosis membrane (RO membrane) is used to separate purified water (60-70% water production rate) and heavy metal concentrate (containing a 3-5 times increase in heavy metal ion concentration) through molecular-level sieving.
[0045] In this invention, the principle of reverse osmosis heavy metal separation is as follows: the RO membrane has a pore size of approximately 0.1 nm, and it blocks ions through a dissolution-diffusion mechanism (water molecules permeate while heavy metal ions are retained). Test data (Table 2) shows that Cu... 2+ The removal rate reached 99.8%, Cr 6+ Removal rate: 99.5%.
[0046] Table 2. Measured data on heavy metal removal rate of reverse osmosis membrane.
[0047] pollutants Influent concentration (mg / L) Product water concentration (mg / L) Removal rate (%) <![CDATA[Cu 2+ ]]> 158.6 0.32 99.8 <![CDATA[Zn 2+ ]]> 73.4 0.15 99.7 <![CDATA[Cr 6+ ]]> 28.5 0.14 99.5
[0048] In this invention, the system further includes a concentrate storage device 5, the input end of which is connected to the output end of the membrane filtration device 3; the concentrate storage device 5 is used to store the concentrate produced by the membrane filtration device 3. The output end of the concentrate storage device 5 is connected to a first discharge pump. Purified water enters the secondary pH adjustment reaction tank 5, where a trace amount of H2SO4 or NaOH is injected via a dosing pump to adjust the pH to 6.8-7.2, after which it is stored in the recycled water storage device 6 and supplied to the production line by a second pump.
[0049] The system also includes a recycled water storage device 6, the input of which is connected to the output of the secondary pH adjustment reaction tank 5. The recycled water storage device 6 is used to store the recycled water generated by the secondary pH adjustment reaction tank 5. The output of the recycled water storage device 6 is connected to a second discharge pump. The concentrate is introduced into the concentrate storage device 4 and then pumped by a first pump to an electrolytic cell to recover heavy metals (such as copper ions regenerated into raw materials for electrolytic copper foil).
[0050] In this invention, the feasibility of recovering the concentrate is verified by using the concentrate (Cu). 2+ The copper concentration (approximately 600 mg / L) is directly recycled into the anolyte of the electrolytic cell. A plant's six-month operation showed a 95% copper recovery rate, saving 340,000 RMB / year in raw material costs. In terms of energy consumption, compared to the evaporation crystallization process (35 kWh per ton of water), this system consumes only 12 kWh per ton of water (85% using high-pressure pumps), resulting in energy savings of 65.7%. Regarding the quality of the recycled water, after two-stage pH adjustment, the conductivity of the product water is <50 μS / cm, and the TDS is <20 mg / L, meeting the standards for copper foil rinsing water (GB / T 29149-2012).
[0051] When the simulated wastewater flow rate fluctuates (±20%), the pH is automatically adjusted by the dosing pump (control accuracy ±0.2) and the high-pressure pump is frequency-controlled (pressure fluctuation <5%), and the concentration of heavy metals in the produced water is always below 0.5 mg / L, proving that the system has industrial-grade stability.
[0052] In summary, this invention utilizes a reverse osmosis membrane to recycle wastewater from the copper foil manufacturing process, removing heavy metal ions from the wastewater and converting it into industrially usable concentrate and purified water. The recycled water is of good quality, the process is simple, energy consumption is low, and the equipment is simple, thereby effectively reducing pollution to the environment.
[0053] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the present utility model. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model.
Claims
1. A water recycling system for copper foil manufacturing processes, characterized in that, include: Two pH adjustment reaction tanks, one precision filter tank (2), and one membrane filter device (3); The two pH adjustment reaction tanks are a primary pH adjustment reaction tank (1) and a secondary pH adjustment reaction tank (5), respectively. The output end of the primary pH adjustment reaction tank (1) is connected to the input end of the precision filter tank (2), the output end of the precision filter tank (2) is connected to the input end of the membrane filter device (3), and the output end of the membrane filter device (3) is connected to the input end of the secondary pH adjustment reaction tank (5). The primary pH adjustment reaction tank (1) is used to adjust the pH value of the wastewater to be treated by adding chemicals; the precision filter tank (2) is used to remove particulate matter from the wastewater after pH adjustment; the membrane filter device (3) is used to concentrate the heavy metal ions in the wastewater into the concentrate by reverse osmosis separation filtration to obtain purified water; the secondary pH adjustment reaction tank (5) is used to adjust the pH value of the purified water by adding chemicals to obtain recycled water.
2. A copper foil manufacturing process water recycling system according to claim 1, characterized in that, The precision filter canister (2) has a filtration accuracy of 5 micrometers.
3. A copper foil manufacturing process water recycling system according to claim 1, characterized in that, The pH adjustment reaction tank includes a tank body, a motor is installed inside the tank body, the output shaft of the motor is connected to a stirring paddle, and a dosing pump is installed at the top of the tank body.
4. A copper foil manufacturing process water recycling system according to claim 1, characterized in that, The membrane filtration device (3) includes a reverse osmosis membrane module, and the input end of the reverse osmosis membrane module is also connected to a high-pressure water pump.
5. A copper foil manufacturing process water recycling system according to claim 1, characterized in that, The system also includes a concentrate storage device (4), the input end of which is connected to the output end of the membrane filtration device (3); the concentrate storage device (4) is used to store the concentrate produced by the membrane filtration device (3).
6. A copper foil manufacturing process water recycling system according to claim 5, characterized in that, The output end of the concentrated liquid storage device (4) is connected to the first discharge pump.
7. A copper foil manufacturing process water recycling system according to claim 1, characterized in that, The system also includes a recycled water storage device (6), the input end of which is connected to the output end of the secondary pH adjustment reaction tank (5); the recycled water storage device (6) is used to store the recycled water generated by the secondary pH adjustment reaction tank (5).
8. A copper foil manufacturing process water recycling system according to claim 7, characterized in that, The output end of the recycled water storage device (6) is connected to the second discharge pump.