Treatment system for an anodizing bath and anodizing system for aluminum products
By treating the anodizing solution with a multi-stage membrane separation system, the problem of unstable oxide film caused by fluctuations in aluminum ion concentration was solved, achieving stable control of aluminum ion concentration and resource recovery, thereby improving the quality of oxide film and system efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 陈全羿
- Filing Date
- 2024-05-09
- Publication Date
- 2026-05-29
AI Technical Summary
In existing technologies, fluctuations in the aluminum ion concentration in the anodizing solution lead to unstable oxide film quality, affecting corrosion resistance and wear resistance, and increasing energy consumption.
A multi-stage membrane separation system is adopted, including a clarification membrane group, a diffusion dialysis membrane group, and a concentration membrane group. The solution in the anodizing tank is treated by ultrafiltration, selective ion exchange, and nanofiltration membranes to achieve stable control of aluminum ion concentration and resource recovery.
This method achieves stable maintenance of aluminum ion concentration in the anodizing solution within an ideal range, improves the corrosion resistance and wear resistance of the oxide film, reduces power consumption, and enhances material utilization and environmental friendliness.
Smart Images
Figure CN224299399U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of metal or alloy anodizing, and more specifically, to an anodizing bath solution treatment system and an aluminum product anodizing system. Background Technology
[0002] Anodizing is an electrochemical surface treatment technique for metals or alloys. In an electrolytic cell containing an acidic solution (such as sulfuric acid), the metal sample acts as the anode, and a direct current is passed through it. An electrochemical reaction occurs on the metal surface, generating metal oxides. These oxides gradually accumulate on the metal surface, forming a dense and uniform oxide film. This oxide film forms a protective layer on the metal surface, improving its corrosion resistance, wear resistance, and other properties. Unless otherwise specified, anodizing usually refers to sulfuric acid anodizing.
[0003] For example, anodizing is widely used in the surface treatment of aluminum products (aluminum and its alloys) to protect the aluminum substrate from corrosion and oxidation. During the anodizing process, excessive aluminum ions in the anodizing solution can lead to a decrease in free acid concentration and reduced conductivity. When a constant voltage process is used, the current density decreases significantly, resulting in insufficient film thickness, reduced transparency, and even unevenness such as white spots, streaks, or other shapes. Using a current-controlled process can cause voltage increases, leading to higher energy consumption and, in severe cases, film burns and blackening after sealing. However, if there are no aluminum ions in the anodizing solution, the oxide film will have strong dissolving power, making it difficult to obtain a normal film thickness, and resulting in poor corrosion resistance and wear resistance. Therefore, the maximum concentration of aluminum ions in the anodizing solution is generally controlled within the range of 20–30 g / L, with a suitable concentration ideally controlled within the range of 3–10 g / L, at which point the obtained oxide film exhibits good corrosion resistance and wear resistance.
[0004] In existing technologies, the anodizing solution is usually treated uniformly when the aluminum ion concentration exceeds the limit. The anodizing process under this operation is not a stable electrochemical reaction process, and the quality of the oxide film is unstable due to the large dynamic changes in the aluminum ion concentration. Utility Model Content
[0005] The technical problem to be solved by the present invention is to provide an anodizing bath solution treatment system and an aluminum product anodizing system that can maintain the concentration of metal ions such as aluminum ions in the anodizing solution within an ideal range.
[0006] To achieve the above objectives, according to the first aspect of this utility model, a system for treating anodizing tank solutions is provided, the technical solution of which is as follows:
[0007] A system for treating an anodizing bath solution, wherein the anodizing bath solution contains acid and metal ions; the system includes a clarification membrane group, a diffusion dialysis membrane group, a concentration membrane group, and a clear liquid storage tank; wherein, the clarification membrane group has an ultrafiltration membrane; after treating the anodizing bath solution, the clarification membrane group outputs a first concentrated solution and a first permeate; the diffusion dialysis membrane group has a selective ion exchange membrane; after treating the first permeate and clear liquid, the diffusion dialysis membrane group outputs a second concentrated solution and a second permeate; the clear liquid inlet of the diffusion dialysis membrane group is connected to the outlet of the clear liquid storage tank; the first permeate inlet of the diffusion dialysis membrane group is connected to the first permeate outlet of the clarification membrane group; the concentration membrane group has a nanofiltration membrane; after treating the second concentrated solution, the concentration membrane group outputs a third concentrated solution and a third permeate; the second concentrated solution inlet of the concentration membrane group is connected to the second concentrated solution outlet of the diffusion dialysis membrane group; the third permeate outlet of the concentration membrane group is connected to the inlet of the clear liquid storage tank.
[0008] In the processing system of this invention, firstly, the solution flowing out of the anodic oxidation tank is separated into solid and liquid by the ultrafiltration membrane of the clarifying membrane module. The equipment has low operating cost and separates a first concentrated liquid (mainly containing solid impurities) and a first permeate (with low impurity content). On the one hand, this reduces the adverse effects of impurities in the first permeate on the subsequent membrane module. On the other hand, it separates the total amount of metal ions into the first concentrated liquid and the first permeate, avoiding large fluctuations in metal ions when the first concentrated liquid flows back to the anodic oxidation tank.
[0009] Then, the first permeate is deacidified by the selective ion exchange membrane of the diffusion dialysis membrane group. The acidity difference on both sides of the ion exchange membrane is used to achieve selective transfer of acidic components from the first permeate. The acid permeation membrane has low resistance and high purity of recovered acid. The output is a second concentrate (low acid concentration, high metal ion concentration) and a second permeate (high acid concentration, low metal ion concentration). When the second permeate is returned to the anodic oxidation tank, the acid can be recycled.
[0010] Subsequently, the metal ions in the second concentrate are further concentrated and separated by the nanofiltration membrane of the concentration membrane group to obtain a third concentrate (high metal ion concentration) and a third permeate (low metal ion concentration), which facilitates the recovery of aluminum resources in the third concentrate in subsequent processing.
[0011] Furthermore, the clear liquid storage tank serves as a recycling link in the system, receiving the third permeate to form a clear liquid that can be reused by the diffusion dialysis membrane module to participate in the exchange of acidic components. This not only reduces the amount of wastewater discharged from the system by about 65-70%, resulting in less wastewater discharge and a more environmentally friendly environment, but also greatly increases the acid utilization rate of the entire system.
[0012] In summary, the above-mentioned treatment system of this utility model adopts a multi-stage membrane separation method, which effectively separates and recycles acidic components and metal ions in the anodizing tank solution, demonstrating good resource recycling and environmental protection. Three different membrane modules are used to purify the oxidation tank liquid without adding any chemicals. Therefore, no additives are mixed into the first concentrate and the second permeate, and both can be directly returned to the production system.
[0013] As a further improvement to the aforementioned anodizing bath solution treatment system, the system also includes a first reflux assembly for returning the first concentrated solution to the anodizing bath. Thus, by returning the first concentrated solution to the anodizing bath, some acid and metal ions are recycled, maintaining the metal ion concentration in the anodizing bath within a certain range. This ensures that the oxide film layer achieves excellent corrosion resistance and wear resistance, while simultaneously preventing voltage increases and increased energy consumption, and significantly improving material utilization.
[0014] As a further improvement to the aforementioned anodizing bath solution treatment system, the system also includes a second reflux assembly for returning the second permeate to the anodizing bath. Thus, by returning the second permeate (high acid concentration, low metal ion concentration) to the anodizing bath, not only can the acidic components in the anodizing bath solution be replenished, reducing the need for external addition of acidic substances and improving the overall material recycling efficiency of the system, but the acid concentration in the anodizing bath is also made more stable, resulting in higher quality anodized products.
[0015] As a further improvement to the above-mentioned anodizing bath solution treatment system, the treatment system also includes a feed pump that feeds the anodizing bath solution into the clarifying membrane module.
[0016] As a further improvement to the above-mentioned treatment system for the anodic oxidation tank solution, the treatment system also includes a clear liquid pump that inputs the clear liquid from the clear liquid storage tank into the diffusion dialysis membrane module.
[0017] As a further improvement to the above-mentioned treatment system for the anodic oxidation bath solution, the treatment system also includes a second concentrate storage tank and a concentrate pump located between the second concentrate outlet of the diffusion dialysis membrane group and the second concentrate inlet of the concentration membrane group.
[0018] As a further improvement to the above-mentioned anodic oxidation tank solution treatment system, the clarified solution storage tank also has a water inlet. This allows water to be added to the clarified solution storage tank to maintain the stable operation of the diffusion dialysis membrane module.
[0019] As a further improvement to the above-mentioned anodizing bath solution treatment system, the concentration membrane module also includes a pressure-reducing mechanism, which is an indirect heat exchange mechanism and / or a membrane flushing mechanism. Thus, indirect heat exchange can reduce the feed temperature of the membrane module, while membrane flushing can prevent pressure increases caused by membrane fouling, helping to ensure stable and efficient operation of the concentration membrane module.
[0020] As a further improvement to the aforementioned anodizing bath solution treatment system, a PLC control component is also included. This allows the PLC control component to monitor key parameters, adjust operating conditions in a timely manner, and achieve automated control of each critical node. It enables coordinated operation of each membrane separation process and automatically maintains a stable metal ion concentration within the anodizing bath, thereby fundamentally eliminating uneven phenomena such as insufficient oxide film thickness, decreased transparency, or even white spots, streaks, or other shapes of marks, ensuring the efficient operation of the entire treatment system.
[0021] To achieve the above objectives, according to a second aspect of this utility model, an anodizing system for aluminum products is provided, the technical solution of which is as follows:
[0022] An anodizing system for aluminum products, including the anodizing bath solution treatment system described in the first aspect above.
[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. Attached Figure Description
[0024] The accompanying drawings, which form part of this utility model, are used to aid in understanding this utility model. The contents provided in the drawings and their related descriptions in this utility model can be used to explain this utility model, but do not constitute an improper limitation of this utility model.
[0025] In the attached diagram:
[0026] Figure 1 This is a schematic diagram of an embodiment of the anodizing tank solution treatment system of this utility model.
[0027] The relevant markings in the above figures are:
[0028] 100-Anodic oxidation tank, 200-Clarifying membrane assembly, 300-Diffusion dialysis membrane assembly, 400-Concentrating membrane assembly, 510-Clearing liquid storage tank, 520-Second concentrated liquid storage tank, 610-First reflux assembly, 620-Second reflux assembly, 710-Supplier pump, 720-Clearing liquid pump, 730-Concentrated liquid pump. Detailed Implementation
[0029] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:
[0030] The technical solutions and features provided in the various parts of this utility model, including the following description, can be combined with each other without conflict.
[0031] Furthermore, the embodiments of the present invention described below are generally only a part of the embodiments of the present invention, and not all of the embodiments. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the protection scope of the present invention.
[0032] Regarding the terminology and units used in this utility model: The terms "comprising," "having," and any variations thereof in the specification, claims, and related parts of this utility model are intended to cover non-exclusive inclusion.
[0033] Figure 1 This is a schematic diagram of an embodiment of the anodizing tank solution treatment system of this utility model.
[0034] like Figure 1 As shown, the anodic oxidation tank solution contains acid and aluminum ions. The anodic oxidation tank solution treatment system includes a clarifying membrane group 200, a diffusion dialysis membrane group 300, a concentrating membrane group 400, a clear liquid storage tank 510, a first reflux assembly 610, a second reflux assembly 620, a raw liquid pump 710, a clear liquid pump 720, a second concentrated liquid storage tank 520, a concentrated liquid pump 730, and a PLC control assembly.
[0035] The clarifying membrane module 200 has an ultrafiltration membrane; after processing the anodizing tank solution, the clarifying membrane module 200 outputs a first concentrate and a first permeate; the anodizing tank solution is input into the clarifying membrane module 200 through the raw solution pump 710; the first concentrate is returned to the anodizing tank 100 through the first reflux assembly 610.
[0036] The diffusion dialysis membrane module 300 has a selective ion-exchange membrane; the diffusion dialysis membrane module 300 processes the first permeate and the clarified liquid and outputs a second concentrated liquid and a second permeate; the clarified liquid inlet of the diffusion dialysis membrane module 300 is connected to the outlet of the clarified liquid storage tank 510; the first permeate inlet of the diffusion dialysis membrane module 300 is connected to the first permeate outlet of the clarification membrane module 200; the second permeate is returned to the anodizing tank 100 through the second reflux assembly 620; the clarified liquid in the clarified liquid storage tank 510 is input into the diffusion dialysis membrane module 300 through the clarified liquid pump 720.
[0037] The concentration membrane module 400 has a nanofiltration membrane and a pressure reduction mechanism; after processing the second concentrate, the concentration membrane module 400 outputs a third concentrate and a third permeate; the second concentrate inlet of the concentration membrane module 400 is connected to the second concentrate outlet of the diffusion dialysis membrane module 300; the third permeate outlet of the concentration membrane module 400 is connected to the inlet of the clear liquid storage tank 510; a second concentrate storage tank 520 and a concentrate pump 730 are provided between the second concentrate outlet of the diffusion dialysis membrane module 300 and the second concentrate inlet of the concentration membrane module 400; the pressure reduction mechanism is an indirect heat exchange mechanism and / or a membrane flushing mechanism.
[0038] The clear liquid storage tank 510 also has a water inlet.
[0039] The PLC control component is preferably located at the following key nodes:
[0040] Clarifying membrane module 200: Adjusting the feed pressure and flow rate enables precise control of the operating parameters of the clarifying membrane module 200, ensuring membrane separation efficiency and stability.
[0041] Diffusion dialysis membrane module 300: Matches the flow rates of the first permeate and the supernatant, controls the normal operation of the diffusion dialysis membrane module 300, and optimizes the separation effect of acidic substances.
[0042] Concentrator 400: Adjust the feed pressure and flow rate to ensure stable operation of the concentrator 400.
[0043] Clarified liquid storage tank 510: Purified water is added to or stopped from being added to the clarified liquid storage tank 510 according to the liquid level detection to maintain the material balance of the diffusion dialysis membrane module 300.
[0044] The following are application examples of the anodizing tank solution treatment system of this utility model.
[0045] Table 1 shows the operating data of the anodizing tank solution treatment system of this invention under actual working conditions. Verification showed that during continuous operation for 15 days, with 580L of pure water added to the clear liquid storage tank 510, the aluminum ion concentration in the anodizing tank 100 was maintained at 6±0.5g / L.
[0046] Table 1
[0047]
[0048] Table 2 shows the operating data of the anodizing tank solution treatment system of this invention under another actual working condition. Verification showed that during continuous operation for 15 days, with 580L of pure water added to the clear liquid storage tank 510, the aluminum ion concentration in the anodizing tank 100 was maintained at 10±0.5g / L.
[0049] Table 2
[0050]
[0051] An embodiment of the aluminum product anodizing system of this utility model is a treatment system including the above-mentioned anodizing tank solution.
[0052] The foregoing has described the relevant content of this utility model. Those skilled in the art will be able to implement this utility model based on these descriptions. All other embodiments obtained by those skilled in the art based on the above description of this utility model without inventive effort should fall within the protection scope of this utility model.
Claims
1. A system for treating anodizing tank solution, wherein the anodizing tank solution contains acid and metal ions, characterized in that: The processing system includes a clarification membrane module (200), a diffusion dialysis membrane module (300), a concentration membrane module (400), and a supernatant storage tank (510); among which, The clarification membrane assembly (200) has an ultrafiltration membrane; after processing the anodizing tank solution, the clarification membrane assembly (200) outputs a first concentrate and a first permeate; The diffusion dialysis membrane module (300) has a selective ion-exchange membrane; the diffusion dialysis membrane module (300) processes the first permeate and the clear liquid and outputs the second concentrated liquid and the second permeate; the clear liquid inlet of the diffusion dialysis membrane module (300) is connected to the outlet of the clear liquid storage tank (510); the first permeate inlet of the diffusion dialysis membrane module (300) is connected to the first permeate outlet of the clarification membrane module (200); The concentration membrane group (400) has a nanofiltration membrane; the concentration membrane group (400) processes the second concentrate and outputs a third concentrate and a third permeate; the second concentrate inlet of the concentration membrane group (400) is connected to the second concentrate outlet of the diffusion dialysis membrane group (300); the third permeate outlet of the concentration membrane group (400) is connected to the inlet of the clear liquid storage tank (510).
2. The anodizing tank solution treatment system as described in claim 1, characterized in that: The processing system also includes a first reflux assembly (610) that returns the first concentrate to the anodizing tank (100).
3. The anodizing tank solution treatment system as described in claim 1, characterized in that: The treatment system also includes a second reflux assembly (620) that returns the second permeate to the anodizing tank (100).
4. The anodizing tank solution treatment system as described in claim 1, characterized in that: The processing system also includes a feed pump (710) that feeds the anodic oxidation tank solution into the clarifying membrane assembly (200).
5. The anodizing tank solution treatment system as described in claim 1, characterized in that: The processing system also includes a clear liquid pump (720) that inputs clear liquid from the clear liquid storage tank (510) into the clear liquid pump in the diffusion dialysis membrane module (300).
6. The anodizing tank solution treatment system as described in claim 1, characterized in that: The processing system also includes a second concentrate storage tank (520) and a concentrate pump (730) located between the second concentrate outlet of the diffusion dialysis membrane unit (300) and the second concentrate inlet of the concentration membrane unit (400).
7. The anodizing tank solution treatment system as described in claim 1, characterized in that: The clear liquid storage tank (510) also has a water inlet.
8. The anodizing tank solution treatment system as described in claim 1, characterized in that: The concentration membrane assembly (400) also has a pressure reduction mechanism, which is an indirect heat exchange mechanism and / or a membrane flushing mechanism.
9. The anodizing tank solution treatment system as described in claim 1, characterized in that: It also includes PLC control components.
10. An anodizing system for aluminum products, characterized in that: The system includes the treatment system for the anodizing bath solution as described in any one of claims 1-9.