Ceramic membrane filter, electroplating liquid filtering and purifying system and purifying method thereof

Abstract

The invention provides a ceramic membrane filter, an electroplating liquid filtering and purifying system and a purifying method thereof, and belongs to the technical field of filtering devices. The ceramic membrane filter comprises a filter shell internally provided with a plurality of ceramic membrane pipes, a connector, a water inlet pipe and a water collecting pipe. The purification system comprises a plating tank, a carbon liquid mixer and the ceramic membrane filter. The ceramic membrane filter, the purification system and the in-situ backwashing system are adopted to replace a traditional wire-wound filter element, the problems that the traditional filter element is low in precision, non-reusable, much in solid waste and high in cost are solved through high-precision filtration and membrane in-situ regeneration, manual operation is reduced to the maximum extent, the labor cost is reduced, solid waste and secondary pollution are avoided, and the method is suitable for industrial production. The advantages of high efficiency, stability, low maintenance and environmental protection are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of filtering devices, in particular to a ceramic membrane filter, an electroplating solution filtering and purifying system comprising the ceramic membrane filter, and a purifying method of the purifying system. BACKGROUND

[0002] Electroplating is a process that deposits a layer of other metal or alloy plating on the surface of a metal by using electrolysis, aiming to prevent oxidation, enhance wear resistance and electrical conductivity, improve light reflection effect, improve corrosion resistance and beautify appearance. As the electroplating process continues, impurity ions and by-products in the plating solution gradually accumulate, and when their concentration reaches a certain threshold, the deposition rate will be significantly slowed down, and the plating layer will exhibit loose and porous characteristics and reduced ductility. Common impurities in the plating solution mainly include organic impurities, metal impurities, and particulate matter. The influence of organic impurities mainly manifests in that the plating layer not only has dull luster, local mottling and stains, but also has increased brittleness and decreased toughness due to increased stress; metal impurities are deposited in low or high current density areas of the plated part due to their different deposition potentials, causing the plating layer to appear black, brittle or mottled; particulate impurities are deposited on the surface of the plated part during electroplating, causing defects such as burrs and coarse grains in the plating layer. Therefore, purification and impurity removal of the electroplating solution is an indispensable link in electroplating production.

[0003] Currently, conventional plating solution purification processes include electrolysis, insoluble salt precipitation, activated carbon adsorption, and filtration. For example, the patent application No. CN202311018137.5 discloses a plating solution purification method: the plating solution in the electroplating tank enters the filter tank through the liquid outlet pipe, removes metal impurity ions under the action of the electrolytic impurity removal device, and then enters the bottom filter to remove particulate impurities. The patent application No. CN201710929109.7 discloses a plating solution purification process: the plating solution to be purified is first mixed with activated carbon powder in a carbon liquid mixer to remove organic impurities by using the strong adsorption performance of activated carbon, and then the plating solution enters the filter module to remove solid impurities, finally obtaining purified plating solution. However, the conventional filtration and impurity removal are all completed by using wire-wound filter cartridges, which has the following disadvantages: (1) the wire-wound filter cartridges have low filtration precision, and fine particulate matter still remains in the plating solution, leading to decreased quality of the plated parts; (2) the wire-wound filter cartridges cannot be regenerated after use and can only be disposed of, increasing the cost of solid waste treatment and the risk of secondary pollution; (3) the wire-wound filter cartridges need to be replaced manually after use, increasing labor costs, and workers are likely to be exposed to harmful substances during disassembly, causing safety risks. SUMMARY

[0004] In view of the above, in order to solve the problems of the traditional wire-wound filter element, the application provides a ceramic membrane filter, an electroplating solution filtering and purifying system comprising the ceramic membrane filter, and a purifying method of the filtering and purifying system.

[0005] To achieve the above object, the application provides the following technical scheme.

[0006] In the first aspect, the application provides a ceramic membrane filter, comprising:

[0007] A filter shell is internally provided with a plurality of ceramic membrane tubes;

[0008] A joint is used for covering the filter shell, and a lower end interface thereof is in communication with the ceramic membrane tubes;

[0009] A water inlet pipe is in communication with an upper end interface of the joint;

[0010] A water collecting pipe is used for collecting filtered liquid filtered by the plurality of ceramic membrane tubes.

[0011] In the second aspect, the application provides an electroplating solution filtering and purifying system, comprising:

[0012] A plating tank is used for containing plating solution;

[0013] A carbon solution mixer is in communication between a water inlet thereof and a liquid outlet of the plating tank;

[0014] The ceramic membrane filter is in communication between a water outlet thereof and a water inlet of the plating tank;

[0015] A first valve is arranged between the plating tank and the carbon solution mixer, a second valve is arranged between the carbon solution mixer and the ceramic membrane filter, and a third valve is arranged between the ceramic membrane filter and the plating tank.

[0016] In the third aspect, the application further provides a purifying method of the electroplating solution filtering and purifying system, comprising the following steps.

[0017] Step (1), continuously active carbon adsorption, the first valve is opened, and the plating solution to be purified is delivered from the plating tank to the carbon solution mixer to be fully mixed with the active carbon therein to fully adsorb organic impurities;

[0018] Step (2), continuous ceramic membrane filtration, open the second valve and the third valve, close the backwashing system, and deliver the plating solution treated by the carbon liquid mixer to the ceramic membrane filter;

[0019] Step (3), in-situ backwashing of the ceramic membrane filter, open the backwashing system, close the second valve and the third valve, deliver the backwashing clean water to the shell side inlet of the ceramic membrane filter, and after a period of backwashing, the flushing waste water flows into the waste water tank, to realize the in-situ regeneration of the ceramic membrane.

[0020] The present application provides a ceramic membrane filter, an electroplating solution filtration and purification system comprising the same, and a purification method of the purification system, which replaces the traditional wire-wound filter element with a ceramic membrane filter, a purification system and an in-situ backwashing system. Compared with the prior art, the present application has the following advantages:

[0021] (1) High-precision filtration and high-efficiency separation

[0022] The ceramic membrane filter uses a ceramic membrane tube, which can trap active carbon and solid impurities with a pore size of ≥200 nm, while the traditional wire-wound filter element can only trap particles with a size of ≥300 nm. The removal rate of suspended solids in the actual plating solution is more than 94%, and the particle size of the filtered solution is ≤200 nm, which can avoid defects such as dull plating and burrs, and improve the quality of plated parts.

[0023] (2) Long service life and low maintenance cost

[0024] The silicon carbide ceramic membrane tube has strong chemical stability and can resist acid and alkali corrosion, and can be repeatedly regenerated.

[0025] The in-situ backwashing system realizes reverse flushing from the shell side to the tube side, and realizes the in-situ regeneration of the ceramic membrane tube without disassembling the membrane assembly. The ceramic membrane tube can be used for a long time, avoiding the generation of solid waste and labor cost caused by frequent replacement of filter elements, reducing the risk of secondary pollution. Through the linkage of valves and water pumps, the filtration-backwashing process can be automatically switched. The backwashing does not need manual disassembly, avoiding the contact of operators with harmful substances in the plating solution, reducing the safety risk, and meeting the needs of industrial unmanned operation.

[0026] In summary, the present application solves the problems of low precision, non-reusability, high cost and solid waste of traditional filter elements by high-precision membrane tube filtration and in-situ regeneration of the membrane tube, greatly reduces manual operation and labor cost, avoids the generation of solid waste and secondary pollution, realizes high efficiency, stability, low maintenance and environmental protection advantages, and provides an efficient and sustainable solution for electroplating solution purification. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a process flow chart of the electroplating solution purification system;

[0028] Figure 2 It is a schematic diagram of the ceramic membrane filter;

[0029] Figure 3 Figure 1 is a schematic diagram of a six-way joint;

[0030] Figure 4 Figure 2 is a schematic diagram of a ceramic membrane tube;

[0031] Figure 5 Figure 3 is a curve of membrane flux and solution particle size distribution of Example 1; wherein (A) is the flux change of Example 1; (B) is the particle size distribution in the solution before and after filtration of Example 1;

[0032] Figure 6 Figure 4 is a curve of membrane flux and suspended matter content change of Example 2; wherein (A) is the flux change of Example 2; (B) is the particle size distribution in the solution before and after filtration of Example 2;

[0033] Figure 7 Figure 5 is a backwashing effect diagram of Example 3;

[0034] Figure 8 Figure 6 is a curve of flux and solution particle size distribution of Comparative Example 1; wherein (A) is the flux change of Comparative Example 1; (B) is the particle size distribution in the solution before and after filtration of Comparative Example 1;

[0035] Figure 9 Figure 7 is a curve of flux and suspended matter content change of Comparative Example 2; wherein (A) is the flux change of Comparative Example 2; (B) is the suspended matter change in the actual plating solution before and after filtration of Comparative Example 2;

[0036] In the figure, 1 is a plating tank; 2 is a carbon liquid mixer; 3 is a ceramic membrane filter; 31 is a ceramic membrane tube; 32 is a joint; 33 is a first chuck; 34 is a second chuck; 35 is a water inlet pipe; 36 is a water collecting pipe; 37 is a filter shell; 4 is a clean water tank; 5 is a waste water tank; 6 is a first water pump; 7 is a second water pump; 8 is a third water pump; 9 is a first valve; 10 is a second valve; 11 is a third valve; 12 is a fourth valve; 13 is a fifth valve. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0038] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom end" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0039] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "provided with", "sleeved / connected", "connected" and the like should be broadly understood, for example, "connected" can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] As shown in Figure 2 The present application provides a ceramic membrane filter 3, characterized by comprising:

[0041] A filter housing 37 is provided with a plurality of ceramic membrane tubes 31. The filter housing 37 is a cylindrical closed structure as a whole, vertically installed in the pipeline of the purification system, and internally accommodates a plurality of ceramic membrane tubes 31.

[0042] A joint 32 is used to cover the filter housing 37, and the lower end interface thereof is in communication with the ceramic membrane tubes 31. The joint 32 is located at the top end of the filter housing 37 and is in a "T" shape or a multi-pass structure, serving as a hub component for liquid inlet and outlet. The joint 32 is preferably a six-way joint 32, and the number of ceramic membrane tubes 31 is preferably five, corresponding to the five openings at the lower end of the flow joint 32, as shown in Figures 3-4 .

[0043] A water inlet pipe 35 is in communication with the upper end interface of the joint 32.

[0044] A water collecting pipe 36 is used to collect the filtered liquid after being filtered by a plurality of ceramic membrane tubes 31.

[0045] In the present application, the upper end opening of the filter housing 37 is sealed and covered with the joint 32, and the side wall of the housing is provided with a shell pass water inlet and outlet for backwashing. The filter housing 37 is used to provide a closed filtering space to protect the plurality of ceramic membrane tubes 31 inside from external pollution.

[0046] The joint 32 is preferably communicated with the upper end opening of each ceramic membrane tube 31 in one-to-one correspondence through an O-shaped sealing ring to form a tube passage liquid inlet channel. The upper end interface of the joint 32 is communicated with the water inlet pipe 35 to receive the plating solution to be filtered from the carbon liquid mixer 2. The plating solution delivered by the water inlet pipe 35 is uniformly distributed to the five ceramic membrane tubes 31 arranged in parallel through the joint 32, ensuring that the flux of each membrane tube is consistent.

[0047] One end of the water inlet pipe 35 is communicated with the water inlet port at the top end of the joint 32 and then communicated with the tube passage inlet of the ceramic membrane tube 31, and the other end can be communicated with the water outlet of the carbon liquid mixer 2 in the purification system described below. The water inlet pipe 35 delivers the plating solution pretreated by the activated carbon in the carbon liquid mixer 2 into the tube passage of the ceramic membrane tube 31 as a “feed channel” of the filtration process, and cooperates with the water pump to provide driving force so that the plating solution enters the ceramic membrane tube 31 at a certain pressure to achieve filtration.

[0048] The water collecting pipe 36 is communicated with the lower end opening of the ceramic membrane tube 31 to collect the filtered solution that passes through the membrane holes, and the filtered solution collected by the water collecting pipe 36 can be delivered to a waste water collecting device, such as the waste water tank 5 described below. The bottom outlet of the water collecting pipe 36 is connected with the return pipe of the plating tank 1 through the third valve 11. The water collecting pipe 36 is used to collect the filtered solution of all ceramic membrane tubes 31 to ensure that the filtered solution is uniformly returned to the plating tank 1 for direct reuse, avoid the residue of the filtered solution, reduce the loss of the plating solution, and improve the processing efficiency of the system.

[0049] In the present application, a first chuck 33 and a second chuck 34 for fixing a plurality of ceramic membrane tubes 31 are further included. The first chuck 33 and the second chuck 34 are fixed at both ends of the ceramic membrane tube 31 to ensure the coaxiality of the ceramic membrane tube 31 and avoid local pollution caused by flow deviation. The shell passage and the tube passage form independent flow channels for filtration (tube passage liquid inlet) and backwashing (shell passage liquid inlet), respectively.

[0050] In the present application, the number of passages of the ceramic membrane tube 31 is preferably 10-35, and more preferably 35. The material of the ceramic membrane tube 31 is preferably alumina, zirconia, silica, silicon nitride or silicon carbide, and more preferably silicon carbide.

[0051] The ceramic filter provided by the present application is an upgrade of the wound filter, which is designed to replace the existing filter in situ, improve the filtration precision, and have an in-situ backwashing function, thereby reducing equipment investment and assisting enterprises in clean production.

[0052] The ceramic filter of the present application realizes high-precision separation of the solution to be filtered through the flow channel design of “water inlet pipe 35→joint 32→ceramic membrane tube 31→water collecting pipe 36”. At the same time, the sealing structure of the filter shell 37 and the joint 32 provides a switching basis for in-situ backwashing, which together guarantees the efficient and long-life operation of the ceramic membrane filter 3.

[0053] As Figure 1As shown, the application also provides a plating solution filtering and purifying system, characterized in that it comprises:

[0054] The plating tank 1 is used for containing plating solution. The plating solution storage and circulation foundation is provided, the production continuity is ensured, the directly reused plating solution after purification is provided, and material loss is reduced.

[0055] The carbon solution mixer 2 is connected with the outlet of the plating tank 1. The carbon solution mixer 2 is located between the plating tank 1 and the ceramic membrane filter 3, and is used as the core device of the pretreatment link. The carbon solution mixer 2 is used for reducing the membrane assembly blockage probability, prolonging the service life of the ceramic membrane tube 31, and improving the operation stability of the whole system.

[0056] The ceramic membrane filter 3 is connected with the outlet of the carbon solution mixer 2 and the inlet of the plating tank 1. The ceramic membrane filter 3 is connected between the carbon solution mixer 2 and the plating tank 1, and is the core filtering component of the system. The silicon carbide ceramic membrane tube 31 (the number is preferably 5 and the number of channels is 35) is used for high-precision filtering, and solid impurities with a size greater than or equal to 200 nm are intercepted, and the filtered liquid has a particle size less than or equal to 200 nm. The filtering precision is far higher than that of the traditional wire-wound filter element (the traditional wire-wound filter element only intercepts particles with a size greater than or equal to 300 nm), the membrane assembly can be regenerated repeatedly, the flux decay rate is only 50% in a 16-day period, and the replacement cost and solid waste generation are reduced.

[0057] The first valve 9 is arranged between the plating tank 1 and the carbon solution mixer 2, the second valve 10 is arranged between the carbon solution mixer 2 and the ceramic membrane filter 3, and the third valve 11 is arranged between the ceramic membrane filter 3 and the plating tank 1.

[0058] In the application, the outlet of the plating tank 1 is connected with the inlet of the carbon solution mixer 2 through a pipeline, and the inlet receives the backflow of the plating solution purified by the ceramic membrane filter 3. The plating solution storage and circulation foundation is provided, the production continuity is ensured, the directly reused plating solution after purification is provided, and material loss is reduced. The closed-loop circulation of the plating solution is realized, the cost waste caused by frequent replacement of new solution is avoided, and the production efficiency is improved.

[0059] The inlet of the carbon solution mixer 2 is connected with the outlet of the plating tank 1, and the outlet is connected with the pipe inlet of the ceramic membrane filter 3 through the second valve 10. The activated carbon in the carbon solution mixer 2 adsorbs the organic impurities in the plating solution, the pollution risk of the subsequent ceramic membrane is reduced, the filtering efficiency is improved, the membrane assembly blockage probability is reduced, the service life of the ceramic membrane is prolonged, and the operation stability of the whole system is improved.

[0060] The ceramic membrane filter 3 is connected between the carbon solution mixer 2 and the plating tank 1, and is the core filtering component of the system. The inlet of the ceramic membrane filter 3 receives the plating solution pretreated by the carbon solution mixer 2, and the outlet is connected with the plating tank 1 through the water collecting pipe 36 and the third valve 11.

[0061] The first valve 9 is located between the plating tank 1 and the carbon liquid mixer 2, and controls the inflow of the plating solution to be treated. The second valve 10 is located between the carbon liquid mixer 2 and the ceramic membrane filter 3, and adjusts the liquid flow into the ceramic membrane tube 31. The third valve 11 is located between the ceramic membrane filter 3 and the plating tank 1, and controls the backflow of the purified plating solution.

[0062] The first valve 9, the second valve 10 and the third valve 11 segmentally control the on-off of the pipeline, and cooperate with the water pump to realize the switching of the filtering and backwashing processes. The first valve 9, the second valve 10 and the third valve 11 precisely regulate the liquid flow direction, pressure and flow rate, and realize the automatic process control (such as filtering / backwashing mode switching). The system switching can be completed without manual intervention, which reduces the risk of operators contacting harmful substances and improves the safety and automation level of industrial production.

[0063] The above-mentioned purification system of the present application realizes efficient purification and recycling of the plating solution through the closed loop design of “plating tank 1→carbon liquid mixer 2 (pre-treatment)→ceramic membrane filter 3 (high-precision filtration)→plating tank 1 (reuse)”, combined with the precise control of the valve system, and takes into account the filtration precision, operation cost and environmental safety, which is significantly superior to the traditional wire-wound filter cartridge technology.

[0064] In the present application, a first water pump 6 is arranged between the plating tank 1 and the carbon liquid mixer 2 and downstream of the first valve 9, a second water pump 7 is arranged between the carbon liquid mixer 2 and the ceramic membrane filter 3 and upstream of the second valve 10, and a third water pump 8 is arranged between the clean water tank 4 and the ceramic membrane filter 3 for in-situ backwashing system.

[0065] The first water pump 6 provides initial power to pump the plating solution to be purified in the plating tank 1 into the carbon liquid mixer 2, and drives the liquid into the pre-treatment link. The flow rate is adjusted in cooperation with the first valve 9 to control the speed of the plating solution entering the mixer, so as to ensure that the activated carbon and the plating solution are in full contact. The feed rate is precisely controlled to avoid insufficient adsorption of activated carbon due to excessive flow rate, and a corrosion-resistant material (such as stainless steel) is used to adapt to the strong acid and alkali environment of the electroplating solution and improve the durability of the equipment.

[0066] The second water pump 7 provides the core driving force for the filtration process, and pressurizes the plating solution after activated carbon pre-treatment to send it into the ceramic membrane tube 31. By adjusting the pump pressure, the plating solution is allowed to pass through the membrane pores in a dead-end filtration mode, and ≥200nm impurities are intercepted. The second water pump 7 provides a stable transmembrane pressure difference to ensure that the filtered liquid has a particle size ≤200nm, and the filtration precision is better than that of the traditional filter cartridge. The variable frequency control design can dynamically adjust the pressure according to the degree of membrane pollution, and maintain long-term high-flux operation.

[0067] The third water pump 8 is started in the backwashing stage to pressurize the backwashing water in the clean water tank 4 and pump it into the shell side of the ceramic membrane filter 3. Through the reverse water flow of the shell side to the tube side, the pollutants trapped on the membrane surface are flushed away, the transmembrane pressure difference is restored to the initial value, the in-situ regeneration of the ceramic membrane filter 3 is realized, the filtering performance is restored without disassembly, and the labor maintenance cost is reduced.

[0068] The three-stage water pump matches the pressure requirements of pretreatment, filtration and backwashing respectively, avoids the efficiency loss caused by excessive load of a single water pump, is linked with the valve system (first / second / third valves 11), realizes automatic switching of the "filtration-backwashing" process through PLC control, and does not need manual intervention. The pump speed is dynamically adjusted according to different working conditions, and the overall energy consumption is reduced.

[0069] In the application, a backwashing system is further included, and the backwashing system comprises:

[0070] The wastewater tank 5 is communicated with the ceramic membrane tube 31 of the ceramic membrane filter 3. The wastewater tank 5 is preferably located below or on the side of the ceramic membrane filter 3 and is independent of the waste liquid collecting unit of the main filtration process. A sewage outlet is arranged at the bottom of the wastewater tank 5 and is connected to a wastewater treatment system. The wastewater tank 5 is specially used for collecting the mixed liquid (containing trapped impurities, residual plating solution, etc.) discharged from the membrane tube in the backwashing stage, temporarily storing the waste liquid until a preset liquid level is reached, and then pumping the waste liquid to a subsequent wastewater treatment unit through a sewage pump, so as to avoid direct discharge and pollution of the environment. The backwashing wastewater and the purified plating solution are completely isolated, and secondary pollution is prevented.

[0071] The clean water tank 4 is communicated with the ceramic membrane shell side of the ceramic membrane filter 3. The clean water tank 4 is used as a storage container for backwashing water. The clean water tank 4 stores the backwashing water and provides clean and impurity-free flushing medium for backwashing. The clean water tank 4 is connected to the third water pump 8 (backwashing pump) and pressurizes the clean water to pump it into the shell side of the membrane filter in the backwashing stage.

[0072] The fourth valve 12 is arranged between the clean water tank 4 and the ceramic membrane filter 3, and the fifth valve 13 is arranged between the wastewater tank 5 and the ceramic membrane filter 3. The fourth valve 12 controls the entry of the backwashing water, and the fifth valve 13 controls the discharge of the backwashing waste liquid.

[0073] In the application, the inlet of the wastewater tank 5 is communicated with the tube side outlet of the ceramic membrane filter 3 through the fifth valve 13. The outlet of the clean water tank 4 is communicated with the shell side inlet of the ceramic membrane filter 3 through the fourth valve 12, and the inlet of the clean water tank 4 is connected to an external water source.

[0074] The fifth valve 13 is linked with the third water pump 8 and is opened only in the backwashing stage. The fifth valve 13 is automatically switched through the PLC control system to ensure strict interlocking with the filtration process, that is, the backwashing valve is completely closed during filtration, and the filtration valve is completely closed during backwashing.

[0075] The fourth valve 12 adjusts the backwash water flow and pressure, controls the washing intensity, and avoids damage to the ceramic membrane tube 31 caused by excessive water pressure. The fifth valve 13 quickly discharges the backwash waste liquid, shortening the washing cycle.

[0076] The double-valve interlocking design eliminates the risk of “filtration / backwash process liquid mixing” and ensures the purity of the purified plating solution.

[0077] Through the reverse flow channel design of “fresh water tank 4→ fourth valve 12→ shell side of ceramic membrane filter 3→ tube side→ fifth valve 13→ waste water tank 5”, combined with the pressurized washing of the third water pump 8, the in-situ efficient regeneration of the ceramic membrane is realized. Compared with the traditional offline cleaning (which requires disassembly of the membrane assembly), the system can restore the membrane flux to more than 90% of the initial value, and the backwash cycle is extended to 16 days (compared to 3-5 days for traditional filter cartridges), significantly reducing downtime maintenance time and replacement cost of consumables. At the same time, the centralized treatment design of the waste water tank 5 meets the environmental protection requirements, realizing the whole-process closed-loop control of “filtration-purification-regeneration-environmental protection”.

[0078] The present application also provides a purification method for the above-mentioned electroplating solution filtration and purification system, comprising the following steps:

[0079] Step (1), continuous activated carbon adsorption, open the first valve 9, and transport the plating solution to be purified from the plating tank 1 to the carbon liquid mixer 2 to mix with the activated carbon therein to fully adsorb organic impurities.

[0080] Step (2), continuous ceramic membrane filtration, open the second valve 10 and the third valve 11, and close the backwash system, transport the plating solution treated by the carbon liquid mixer 2 to the ceramic membrane filter 3.

[0081] Step (3), in-situ backwash of the ceramic membrane filter 3, open the backwash system, close the second valve 10 and the third valve 11, transport the backwash clean water to the shell side inlet of the ceramic membrane filter 3, and after a period of backwash, the washing waste water flows into the waste water tank 5, realizing the in-situ regeneration of the ceramic membrane.

[0082] The present application is described in detail in combination with the accompanying drawings Figure 1 The above-mentioned purification method is described in detail as follows:

[0083] Step (1), continuous activated carbon adsorption, open the first valve 9, and transport the plating solution to be purified from the plating tank to the carbon liquid mixer 2 by the first water pump 6 to mix with the activated carbon therein to fully adsorb organic impurities.

[0084] Step (2), continuous ceramic membrane filtration, open the second valve 10 and the third valve 11, close the fourth valve 12 and the fifth valve 13, the activated carbon treated plating solution is transported into the ceramic membrane filter 3 by the second water pump 7, and the activated carbon mixed in the plating solution is removed by membrane filtration. The ceramic membrane filter 3 has higher interception precision than the original wire-wound filter and can be repeatedly used to save labor cost.

[0085] Step (3), in-situ backwashing of the ceramic membrane filter 3, open the fourth valve 12 and the fifth valve 13, close the second valve 10 and the third valve 11, the backwashing clean water is transported from the water storage tank to the shell side inlet of the ceramic membrane filter 3 by the third water pump 8, and after a period of backwashing, the washing waste water flows into the waste water tank, so that the ceramic membrane is regenerated in-situ. The backwashing process does not need manual disassembly, and pollution and safety risks are avoided.

[0086] The technical solutions of the present application will be clearly and specifically described in combination with specific embodiments.

[0087] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present application are conventional reagents, methods, instruments and equipment in the art.

[0088] In the following examples, the activated carbon particles used are purchased from Suzhou Carbon Cyclone Activated Carbon Co., Ltd., the silicon carbide membrane is purchased from Shandong Selekico Membrane Technology Co., Ltd., and the actual ammonia-nickel plating solution is taken from Maoying Electronics (Shanghai) Co., Ltd.

[0089] Example 1

[0090] Pure water is used as a simulated plating solution and is placed in the plating tank 1, the first valve 9, the second valve 10 and the third valve 11 are opened, the fourth valve 12 and the fifth valve 13 are closed, the first water pump 6 is opened to transport the pure water into the carbon liquid mixer 2 to prepare a feed liquid with an activated carbon concentration of 5 g / L, then the second water pump 7 is opened to transport the activated carbon-containing feed liquid to the ceramic membrane filter 3 pipe, the feed liquid is filtered by membrane under an initial pressure of 0.2 MPa, the filtrate is collected in the ceramic membrane shell side water collection pipe 36, and the flux of the ceramic membrane filter 3 and the particle size change of the supernatant in the feed liquid before and after membrane filtration are recorded. The particle size is detected by a Malvern particle size analyzer, and the flux value J (L / (m 2 h) is calculated according to formula 1:

[0091]

[0092] In the formula, V (L) is the volume of the filtrate in the time interval t (h), and A (m2) is the effective membrane area. The results are shown in Table A. Figure 5 The ceramic membrane flux gradually decreases from 10000 L / (m 2 h) to 4000 L / (m 2h), the decline rate was 60%. The particle size analysis of the solution before and after filtration showed that Figure 5 As shown in (B), the ceramic membrane had good interception effect on the activated carbon, and the 400 nm particles in the original solution were completely intercepted, and the filtered solution only contained activated carbon particles with a particle size of 200 nm, which could meet the production requirements.

[0093] Example 2

[0094] The actual nickel sulfamate plating solution to be purified was placed in the plating tank 1, the first valve 9, the second valve 10 and the third valve 11 were opened, the fourth valve 12 and the fifth valve 13 were closed, and the first water pump 6 was opened to deliver the plating solution to the carbon liquid mixer 2 to allow the activated carbon to fully adsorb the organic matter in the plating solution. Then, the second water pump 7 was opened to deliver the plating solution after activated carbon adsorption to the ceramic membrane filter 3 pipe, the plating solution was filtered under an initial pressure of 0.1 MPa, the purified plating solution was collected in the ceramic membrane shell collection pipe 36, and the flux of the ceramic membrane filter 3, the change in the content of suspended matter in the plating solution before and after membrane filtration were recorded. The suspended matter was detected according to the national standard (GB11901-89), and the flux value was calculated according to the method described in Example 1. The results are shown in Table 2. Figure 6 As shown in (A), the ceramic membrane flux gradually decreased from 17500 L / (m 2 h) to 8000 L / (m 2 h) in a 16-day operation cycle, showing good stability. The analysis of the suspended matter in the solution before and after filtration showed that Figure 6 As shown in (B), the ceramic membrane could significantly remove the suspended particles in the plating solution, and the content of suspended matter decreased significantly from 3500 to below 200, showing the outstanding performance advantage of the ceramic membrane.

[0095] Example 3

[0096] The backwashing effect evaluation, the actual nickel sulfamate plating solution to be purified was placed in the plating tank 1, the first valve 9, the second valve 10 and the third valve 11 were opened, the fourth valve 12 and the fifth valve 13 were closed, and the first water pump 6 was opened to deliver the plating solution to the carbon liquid mixer 2 to allow the activated carbon to fully adsorb the organic matter in the plating solution. Then, the second water pump 7 was opened to deliver the plating solution after activated carbon adsorption to the ceramic membrane filter 3 pipe, the plating solution was filtered under an initial pressure of 0.1 MPa, and the purified plating solution was collected in the ceramic membrane shell collection pipe 36. In-situ backwashing was performed on the ceramic membrane after long-term operation, and the operation steps were as follows: the fourth valve 12 and the fifth valve 13 were opened, the second valve 10 and the third valve 11 were closed, and the third water pump 8 was used to deliver the backwashing clean water from the clean water tank to the ceramic membrane filter 3 shell inlet, and the backwashing was performed at 0.25 MPa for 5 min as one cleaning cycle. The cleaned ceramic membrane filter 3 was used again for the treatment of electroplating solution purification, and the recovery of the transmembrane pressure difference was used as the evaluation index of the cleaning effect. The results are shown in Table 3. Figure 7As shown in the figure, the transmembrane pressure difference rises to 0.35 MPa as the time for backwashing. After cleaning, the transmembrane pressure difference can be restored to the initial value. The ceramic membrane shows a stable treatment effect under three cleaning-running cycles. The above shows that the ceramic membrane filter 3 has great advantages in terms of reuse.

[0097] Comparative Example 1

[0098] To evaluate the filtering effect of the wire-wound filter element on the simulated plating solution, the ceramic membrane in the ceramic membrane filter 3 was replaced with a wire-wound filter element. Pure water was used as the simulated plating solution and placed in the plating tank 1. The first valve 9, the second valve 10 and the third valve 11 were opened. The fourth and fifth valves 13 were closed. The first water pump 6 was turned on to transport the pure water to the carbon-liquid mixer 2 to prepare a liquid with an activated carbon concentration of 5 g / L. Subsequently, the second water pump 7 was turned on to transport the activated carbon-containing liquid to the wire-wound filter element filter. The liquid was filtered through the wire-wound filter element at an initial pressure of 0.2 MPa, and the filtrate was collected in the filter collection pipe 36. At the same time, the filter flux and the change in the particle size of the supernatant particles in the liquid before and after filtration were recorded. The results are shown in Figure 8 As shown in (A), the flux of the wire wound filter element increased from 12000L / (m 2 h) dropped sharply to 3000L / (m 2 h), the flux attenuation rate reached 71%, and there were still a large number of particles larger than 300nm in the solution after filtering through the wire-wound filter element ( Figure 8 The above shows that ceramic membrane has stronger resistance to activated carbon impact and higher filtration accuracy than wire wound filter element.

[0099] Comparative Example 2

[0100] To evaluate the filtering effect of the wire-wound filter element on the actual plating solution, the ceramic membrane in the ceramic membrane filter 3 was replaced with a wire-wound filter element. The actual nickel sulfamate plating solution to be purified was placed in the plating tank 1, the first valve 9, the second valve 10 and the third valve 11 were opened, the fourth valve 12 and the fifth valve 13 were closed, the first water pump 6 was turned on to transport the plating solution to the carbon-liquid mixer 2 so that the activated carbon could fully adsorb the organic matter in the plating solution, and then the second water pump 7 was turned on to transport the plating solution after the activated carbon adsorption to the wire-wound filter element filter. The plating solution was filtered through the wire-wound filter element at an initial pressure of 0.05 MPa, and the purified plating solution was collected through the water collection pipe 36. At the same time, the filter flux and the content of suspended matter in the plating solution before and after the filter element filtration were recorded. The results are shown in Figure 9 As shown in (A), the flux of the wire wound filter element is maintained at 22000L / (m 2 h), but due to its larger pore size, the suspended matter content in the filtrate is still close to 500 (e.g. Figure 9 (as shown in (B)).

[0101] The above shows that compared with the ceramic membrane, the wire-wound filter element can maintain a high flux, but the particle content in the filtrate is high, which can easily cause defects of the plated parts.

[0102] The above merely describes the preferred embodiments of the present application. The protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacements or changes to the technical solutions and the improvement concepts of the present application within the technical scope disclosed by the present application, which should be covered by the protection scope of the present application.

Claims

1. A ceramic membrane filter, characterized in that include: a filter housing in which a plurality of ceramic membrane tubes are arranged; A connector, used to cover the filter housing, with its lower end interface communicating with the ceramic membrane tube; A water inlet pipe is connected to the upper end interface of the joint; The water collecting pipe is used to collect the filtrate after being filtered by the plurality of ceramic membrane tubes.

2. A ceramic membrane filter according to claim 1, characterized in that: It also includes a first chuck and a second chuck for fixing a plurality of the ceramic membrane tubes.

3. A ceramic membrane filter according to claim 1, characterized in that: The number of channels of the ceramic membrane tube is 10 to 35.

4. A ceramic membrane filter according to claim 3, characterized in that: The number of channels of the ceramic membrane tube is 35.

5. A ceramic membrane filter according to claim 1, characterized in that: The number of the ceramic membrane tubes is 5, and the joint is a six-way joint.

6. A ceramic membrane filter according to any one of claims 1 to 5, characterized in that: The ceramic membrane tube is made of aluminum oxide, zirconium oxide, silicon oxide, silicon nitride or silicon carbide.

7. A ceramic membrane filter according to claim 6, characterized in that: The ceramic membrane tube is made of silicon carbide.

8. A plating liquid filtration and purification system, characterized in that: include: Plating tank, used to hold plating solution; a carbon-liquid mixer, the water inlet of which is connected to the liquid outlet of the plating tank; A ceramic membrane filter according to any one of claims 1 to 7, wherein the water inlet of the ceramic membrane tube side is connected to the water outlet of the carbon-liquid mixer, and the water outlet of the ceramic membrane shell side is connected to the liquid inlet of the coating tank; A first valve is provided between the plating tank and the carbon-liquid mixer, a second valve is provided between the carbon-liquid mixer and the ceramic membrane filter, and a third valve is provided between the ceramic membrane filter and the plating tank.

9. The electroplating liquid filtration and purification system according to claim 4, characterized in that: Also included is a backwash system, the backwash system comprising: a waste water tank, the water inlet of which is connected to the water outlet of the ceramic membrane tube of the ceramic membrane filter; A clean water tank, the water outlet of which is connected to the water inlet of the ceramic membrane shell of the ceramic membrane filter; A fourth valve is provided between the clean water tank and the ceramic membrane filter, and a fifth valve is provided between the waste water tank and the ceramic membrane filter.

10. The purification method of the electroplating liquid filtration and purification system according to claim 8 or 9, characterized in that: The steps include: Step (1), continuous activated carbon adsorption, opening the first valve, transporting the plating solution to be purified from the plating tank to the carbon-liquid mixer to be fully mixed with the activated carbon therein to fully adsorb organic impurities; Step (2), continuous ceramic membrane filtration, open the second valve and the third valve, close the backwash system, and transport the plating solution treated by the carbon-liquid mixer into the ceramic membrane filter; Step (3), backwashing the ceramic membrane filter in situ, opening the backwash system, closing the second valve and the third valve, and delivering the backwash clean water to the shell inlet of the ceramic membrane filter. After backwashing for a period of time, the flushing wastewater flows into the wastewater tank, realizing the in-situ regeneration of the ceramic membrane.

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