A device and method for treating copper-containing wastewater

Abstract

The application discloses a kind of copper-containing wastewater treatment device and method, belong to wastewater treatment technical field.The device is by setting up by high heat-conducting metal material multidimensional heat bridge unit in freezing chamber, constructs axial radial mesoscale three-dimensional body phase heat transfer network, effectively reconstructs solution thermal resistance distribution, breaks the limit of traditional interface heat transfer.The method utilizes the above device, through wastewater pretreatment, device debugging, freezing concentration and the like steps, forms uniform temperature gradient, excites thermophoresis and ice crystal expulsion collaborative mechanism, realizes copper ion directional migration and efficient concentration.The application does not need to add chemical reagent, without secondary pollution, with the advantages of high concentration efficiency, low energy consumption, stable operation and strong adaptability.

Description

Technical Field

[0001] This invention belongs to the field of heavy metal wastewater treatment technology, specifically relating to a copper-containing wastewater treatment device and method. Background Technology

[0002] Progressive freezing concentration, as a heavy metal wastewater treatment technology, has attracted attention due to its advantages of not requiring the addition of chemical agents and not generating secondary pollution. Currently, it mainly involves unidirectionally introducing cold energy from the outer wall of the container to freeze the solution surface. The separation of impurities is achieved by utilizing the displacement effect of the solute during the ice crystal growth process. To optimize this process, technicians have adopted boundary optimization strategies such as improving the flow rate of the cooling medium, enhancing the thermal conductivity of the container wall, and optimizing the structure of the stirring paddle, in an attempt to improve heat transfer efficiency and ice crystal purity.

[0003] However, current cooling methods only allow for unidirectional heat transfer through the container walls, resulting in severe thermal hysteresis within the solution and creating a significant surface-to-bulk temperature gradient. This not only causes uneven ice crystal growth and the easy trapping of copper ions by the ice crystal lattice, but also fails to address the fundamental problem of accumulated bulk thermal resistance through simple boundary optimization. Some technologies attempt to insert metal components, but the lack of mesoscale adaptation design often leads to uneven heat transfer or even disrupts the stability of ice crystal growth. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the present invention provides a copper-containing wastewater treatment device and method, which effectively overcomes the four core problems existing in the current progressive freeze concentration technology: interface heat transfer limitation, bulk thermal resistance accumulation, disordered copper ion migration, and poor scenario adaptability.

[0005] One embodiment of the present invention provides a copper-containing wastewater treatment device, including a freezing chamber, an insulated chamber, a multi-dimensional thermal bridge unit, a temperature field intelligent monitoring system, a liquid storage unit, a freezing control system, and auxiliary structures;

[0006] The heat insulation chamber is fitted outside the freezing chamber, the multi-dimensional thermal bridge unit is disposed inside the freezing chamber, the temperature field intelligent monitoring system is coupled to the freezing chamber, the liquid storage unit is connected to the freezing chamber, the freezing control system is connected to the temperature field intelligent monitoring system, and the auxiliary structure is used for fixing and sealing.

[0007] The multidimensional thermal bridge unit is made of a high thermal conductivity metal material and is used to reconstruct the heat transfer path of the solution phase and break the interface heat transfer limitation through the synergistic effect of thermal bridge and disturbance.

[0008] This invention discloses a copper-containing wastewater treatment device. An insulated chamber is fitted outside a freezing chamber, effectively reducing cold loss and creating a stable low-temperature environment for the freeze-concentration process. A multi-dimensional thermal bridge unit, constructed of a highly thermally conductive metal material, is located within the freezing chamber. Its core function is to reconstruct the heat transfer path within the solution, transforming the traditional unidirectional interfacial heat transfer mode into efficient bulk multi-dimensional heat transfer, fundamentally overcoming the limitations of interfacial heat transfer. A temperature field intelligent monitoring system is coupled to the freezing chamber, enabling real-time and accurate monitoring of the solution temperature gradient. This monitoring system is connected to the freezing control system, forming a closed-loop control that dynamically adjusts the refrigeration intensity, ensuring the uniformity and stability of the temperature field throughout the freezing process. A liquid storage unit is connected to the freezing chamber, enabling the orderly transport of wastewater and efficient collection of the concentrate. All components are precisely fixed and effectively sealed through the auxiliary structure, ensuring the reliability and long-term stability of the device. The overall technical solution of this claim, through system integration and collaborative innovation, achieves efficient and stable treatment of copper-containing wastewater.

[0009] In one embodiment, the high thermal conductivity metal material is one or more of 304 stainless steel, copper, titanium and aluminum, and its surface is covered with a gradient corrosion-resistant coating of silicon nitride or aluminum oxide, with the coating thickness to the dielectric size ratio being 1:100 to 1:50.

[0010] In one embodiment, the freezing chamber is cylindrical with an inner diameter of 50 mm to 100 mm and a height of 100 mm to 200 mm;

[0011] The multidimensional thermal bridge unit includes one or more of metal rods, metal sheets, and metal particles. The diameter of the metal rod is 1% to 8% of the inner diameter of the freezing chamber, and the total length is 50% to 150% of the height of the freezing chamber. When there are multiple metal rods, they are arranged in an equilateral triangle or a ring.

[0012] The thickness of the metal sheet is 0.5% to 3% of the height of the freezing chamber, the width is 60% to 90% of the inner diameter of the freezing chamber, and the height is 50% to 75% of the height of the freezing chamber.

[0013] The particle size of the metal particles is 1% to 5% of the inner diameter of the refrigeration chamber, and the amount added is 5% to 20% of the wastewater volume.

[0014] In one embodiment, the multidimensional thermal bridge unit is equipped with a vortex stirring unit, including an anchor-type or propeller-type stirring paddle and a variable frequency motor. The stirring paddle is made of polypropylene or stainless steel and its diameter is less than or equal to 60% of the inner diameter of the freezing chamber.

[0015] The stirring speed is dynamically adjusted according to the particle size of the metal particles. When the particle size is less than or equal to 2% of the inner diameter of the freezing chamber, the speed is 200 to 300 rpm. When the particle size is greater than 2% of the inner diameter of the freezing chamber, the speed is 50 to 150 rpm.

[0016] In one embodiment, the intelligent temperature field monitoring system includes multiple PT100 platinum resistance temperature sensors with a measurement accuracy of ±0.1 degrees Celsius, which are inserted into the solution at positions of 10% of the height from the bottom, 50% of the height, and 10% of the height from the surface.

[0017] In one embodiment, the sidewalls of the insulated chamber are provided with a 40 mm to 60 mm thick polystyrene foam insulation layer, and the bottom is provided with an 80 mm to 120 mm thick polystyrene foam insulation layer, with a thermal conductivity of less than or equal to 0.03 W / m Kelvin.

[0018] One embodiment of the present invention provides a method for treating copper-containing wastewater, which is implemented based on the copper-containing wastewater treatment method described in the above embodiment, and includes the following steps:

[0019] Wastewater pretreatment steps include filtering copper-containing wastewater and adjusting the pH value;

[0020] The device commissioning steps include selecting and installing a suitable multidimensional thermal bridge unit;

[0021] The feeding process includes injecting wastewater into the refrigeration chamber;

[0022] The system startup and control steps include starting the refrigeration control system and the intelligent temperature field monitoring system to control the temperature gradient;

[0023] The freeze concentration step includes maintaining a freeze environment to allow copper ions to migrate and accumulate in a directional manner;

[0024] The concentrate collection step includes collecting the bottom concentrate.

[0025] This invention discloses a method for treating copper-containing wastewater. Through the systematic integration of six steps—wastewater pretreatment, device commissioning, feeding, system startup and control, freeze concentration, and concentrate collection—a complete and synergistic treatment process is constructed. This achieves standardized operation and precise temperature field control, effectively promoting the synergistic enhancement of heat and mass transfer, thereby improving the efficiency of directional migration and enrichment of copper ions. At the same time, it optimizes resource recovery and process energy consumption, demonstrating the advantages of high efficiency, stability, and environmental protection.

[0026] In one embodiment, during the debugging process, wastewater is first injected, and pre-cooled metal particles are gradually added according to the freezing rate during the freezing process.

[0027] The pre-freezing temperature is between -25°C and -5°C to form a local low-temperature core to increase the migration rate of copper ions, or a combination of metal rods, sheets or granules can be selected according to the initial concentration of wastewater and the scale of treatment.

[0028] In one embodiment, during the freeze concentration step, the bulk heat transfer network constructed by the multidimensional thermal bridge unit creates a uniform temperature gradient in the solution. Copper ions migrate to the unfrozen region under the drive of thermophoretic force, while the ice crystal displacement effect compresses the migration space of copper ions, thereby achieving efficient concentration and recovery of copper ions.

[0029] In one embodiment, the filtration process in the wastewater pretreatment step includes filtering copper-containing wastewater using a 0.45-micron filter membrane to remove suspended particulate matter with a particle size greater than 1 micron, with an initial copper ion concentration of 100 mg / L to 500 mg / L.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] This invention introduces multi-dimensional thermal bridge units to construct a three-dimensional bulk heat transfer network with synergistic axial, radial, and mesoscale effects. This reconstructs the thermal resistance distribution pattern of the solution, transforming the traditional one-dimensional heat transfer path relying on interfacial conduction into a multi-dimensional bulk heat transfer mode. This design ensures that the internal and external temperature gradients of the solution are stably controlled within 3 degrees Celsius, eliminating thermal hysteresis and creating conditions for uniform ice crystal growth. Furthermore, this invention achieves a synergistic effect of thermophoresis and ice crystal displacement. Copper ions migrate directionally to the unfrozen zone under the drive of a stable temperature gradient. Simultaneously, the displacement effect during ice crystal growth further compresses the ion migration space, creating a concentration gradient amplification effect and improving the concentration efficiency and recovery rate of copper ions. Through mesoscale proportional design and dynamic / static mode adaptation, this device flexibly responds to different treatment scenarios, shortens freezing time, eliminates the need for chemical additives, avoids secondary pollution, and allows for the reuse of multi-dimensional thermal bridge units, reducing operating costs. This provides an efficient, stable, and highly adaptable technical solution for the resource-based treatment of copper-containing wastewater. Attached Figure Description

[0032] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0033] Figure 1 This is a schematic diagram of the structure of the present invention;

[0034] Figure 2 These are schematic diagrams illustrating the structure and arrangement of different high thermal conductivity metallic media of the present invention;

[0035] Figure 3 This is a schematic diagram of the hollow modification of the high thermal conductivity metallic medium of the present invention.

[0036] In the picture:

[0037] 11. Vortex stirring unit; 12. Temperature control and acquisition system; 13. Raw material waste liquid; 14. Insulated chamber; 15. Multidimensional thermal bridge unit; 16. Freezing chamber; 17. Purified liquid; 18. Concentrated liquid. Detailed Implementation

[0038] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0039] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0040] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0041] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0042] Combination Figures 1 to 3 As shown, one embodiment of the present invention provides a copper-containing wastewater treatment device, including a freezing chamber 16, an insulated chamber 14, a temperature control and acquisition system 12; a multi-dimensional thermal bridge unit 15, a temperature field intelligent monitoring system, a liquid storage unit, a freezing control system, and auxiliary structures;

[0043] The insulation chamber 14 and the temperature control and acquisition system 12 are described. The insulation chamber 14 is fitted outside the freezing chamber 16. The multi-dimensional thermal bridge unit 15 is disposed inside the freezing chamber 16. The intelligent temperature field monitoring system is coupled to the freezing chamber 16. The liquid storage unit is connected to the freezing chamber 16. The freezing control system is connected to the intelligent temperature field monitoring system. The auxiliary structure is used for fixing and sealing.

[0044] The multidimensional thermal bridge unit 15 is made of a high thermal conductivity metal material and is used to reconstruct the heat transfer path of the solution phase and break the interface heat transfer limitation through the synergistic effect of thermal bridge and disturbance.

[0045] This invention discloses a copper-containing wastewater treatment device, comprising an insulated chamber 14 and a temperature control and acquisition system 12. The insulated chamber 14 is fitted outside the freezing chamber 16, effectively reducing cold loss and creating a stable low-temperature environment for the freezing and concentration process. A multi-dimensional thermal bridge unit 15, made of a high thermal conductivity metal material, is located inside the freezing chamber 16. Its core function is to reconstruct the heat transfer path inside the solution, transforming the traditional unidirectional interface heat transfer mode into efficient bulk multi-dimensional heat transfer, fundamentally breaking through the limitations of interface heat transfer. The intelligent temperature field monitoring system is coupled to the freezing chamber 16, realizing real-time and accurate monitoring of the solution temperature gradient. This monitoring system is connected to the freezing control system, forming a closed-loop control that can dynamically adjust the refrigeration intensity, ensuring the uniformity and stability of the temperature field throughout the freezing process. The liquid storage unit is connected to the freezing chamber 16, realizing the orderly transportation of wastewater and the efficient collection of the concentrate 18. All components are precisely fixed and effectively sealed through the auxiliary structure, ensuring the reliability and long-term stability of the device operation. The overall technical solution of this claim achieves efficient and stable treatment of copper-containing wastewater through system integration and collaborative innovation.

[0046] It should be noted that the freezing chamber 16 is a cylindrical sealed cavity that provides space for freezing and concentration reaction. It is made of polyethylene terephthalate (PET) or PP, with an inner diameter of 50-100mm, a height of 100-200mm, a wall thickness of 0.02-0.05mm, and a smooth inner wall with no adsorption.

[0047] Insulated chamber 14, temperature control and acquisition system 12; The insulated chamber 14 is installed outside the freezing chamber 16, and the side walls and bottom are respectively provided with polystyrene foam insulation layers of 40-60mm and 80-120mm thickness, with a thermal conductivity ≤0.03W / (m・K) to reduce cold loss;

[0048] Multidimensional thermal bridge unit 15: This is the core innovative component of the present invention. Breaking through the limitations of traditional "single component addition," it constructs a three-dimensional heat transfer network of "axial-radial-mesoscale" to achieve directional control of thermal resistance, including:

[0049] 1. Axial thermal bridge (metal rod): 1-5 rods, made of high thermal conductivity metal (thermal conductivity ≥15W / (m・K)), diameter d=D×(1%-8%) (based on the thermal boundary layer penetration theory, to ensure penetration of the solution thermal boundary layer and avoid local heat concentration), total length L=H×(50%-150%) (exposed section is the cold capture end, immersed section is the cold conduction end), multiple rods are arranged in an equilateral triangle / ring, adjacent spacing ≥d×3 (based on the heat transfer superposition effect, to avoid heat transfer area overlap and form a uniform bulk phase heat transfer network);

[0050] 2. Radial thermal bridge (metal sheet): 1-3 sheets, made of the same material as the metal rod, with a thickness t=H×(0.5%-3%) (balancing structural stability and heat transfer area), a width W=D×(60%-90%) (adapting to the chamber cross-section and maximizing radial heat transfer coverage), and a height h=H×(50%-75%) (ensuring effective immersion depth). The surface is provided with corrugated microgrooves with a depth of 0.5-1mm (based on the micro-convection enhancement theory, generating local micro-vortices, breaking the laminar boundary layer, and enhancing radial mass transfer).

[0051] 3. Mesoscale thermal bridge (metal particles): Particle size r = D × (1%-5%) (mesoscale design, taking into account both suspension and heat transfer efficiency), the addition amount is 5%-20% of the wastewater volume, equipped with a vortex stirring unit 11 (stirring blade diameter ≤ D × 60%), and the particles are uniformly suspended by frequency conversion speed control (50-300 rpm) to form "mesoscale heat transfer nodes" to fill the heat transfer gaps of axial / radial thermal bridges.

[0052] Furthermore, the intelligent temperature field monitoring system includes temperature sensors and data loggers. The sensors are inserted into the solution at different depths (H×10% from the bottom, H×50% from the middle, and H×10% from the surface) to monitor the internal and external temperature gradients in real time.

[0053] Liquid storage unit: includes a raw material liquid tank and a concentrated liquid collection tank, which are connected to the freezing chamber 16 through pipes, and the pipes are equipped with valves to control the on and off;

[0054] Refrigeration control system: consists of a low-temperature constant temperature chamber (temperature control range -25℃ to -5℃) and a temperature controller, which are electrically connected to the temperature acquisition system to dynamically adjust the refrigeration temperature;

[0055] Auxiliary structure: includes a fixing bracket (for fixing metal rods and metal sheets, made of PP / UPVC), and a sealing cap (with a medium perforation, sampling port, and sealing gasket), such as Figure 1 The black L-shaped fixing device on the side wall of the intermediate tank, and the dotted lines on the tank body represent fixing devices for metal rods and plates. A sealing cap is also installed on the side wall of the tank, located at the inlet of the raw material waste liquid 13 and the outlets of the purified liquid 17 and the concentrated liquid 18. Figure 1 This is shown in the text and explained here.

[0056] In one embodiment, the high thermal conductivity metal material is one or more of 304 stainless steel, copper, titanium and aluminum, and its surface is covered with a gradient corrosion-resistant coating of silicon nitride or aluminum oxide, with the coating thickness to the dielectric size ratio being 1:100 to 1:50.

[0057] In this embodiment, by covering the surface of high thermal conductivity metals such as 304 stainless steel, copper, titanium, and aluminum with a gradient coating of silicon nitride or aluminum oxide, an optimal balance between corrosion resistance and heat transfer efficiency is achieved. The coating thickness to medium size ratio of 1:100 to 1:50 is designed to ensure sufficient corrosion protection while minimizing the impact of the coating's thermal resistance.

[0058] The gradient corrosion-resistant coating effectively blocks the chemical corrosion of the metal substrate by copper-containing wastewater, and is especially suitable for highly corrosive wastewater environments in industries such as electroplating and chemical processing, thus extending the service life of the multidimensional thermal bridge unit 15.

[0059] The protective effect of the coating ensures the long-term stability of the surface properties of the metal medium, avoids the decay of heat transfer performance due to corrosion, and enables the freeze concentration process to maintain a stable temperature field and heat transfer efficiency.

[0060] By combining and adapting different metal materials and coatings, the device can flexibly cope with copper-containing wastewater of varying corrosiveness, thus expanding the application range of the technology.

[0061] In one embodiment, the freezing chamber 16 is cylindrical with an inner diameter of 50 mm to 100 mm and a height of 100 mm to 200 mm;

[0062] The multidimensional thermal bridge unit 15 includes one or more of metal rods, metal sheets, and metal particles. The diameter of the metal rod is 1% to 8% of the inner diameter of the freezing chamber 16, and the total length is 50% to 150% of the height of the freezing chamber 16. When there are multiple metal rods, they are arranged in an equilateral triangle or a ring.

[0063] The thickness of the metal sheet is 0.5% to 3% of the height of the freezing chamber 16, the width is 60% to 90% of the inner diameter of the freezing chamber 16, and the height is 50% to 75% of the height of the freezing chamber 16.

[0064] The particle size of the metal particles is 1% to 5% of the inner diameter of the 16-cell refrigeration chamber, and the amount added is 5% to 20% of the wastewater volume.

[0065] In this embodiment, the freezing chamber 16 adopts a cylindrical structure, with an inner diameter of 50-100 mm and a height range of 100-200 mm, providing a reasonable space for phase change reaction. The metal rods are designed with a diameter ratio of 1%-8% of the inner diameter of the chamber and a length ratio of 50%-150% of the height, and combined with an equilateral triangle or ring arrangement, they form a spatially balanced axial heat transfer main channel.

[0066] The metal sheet design balances structural function and heat transfer requirements. The thickness is 0.5%-3% of the chamber height to ensure sufficient structural rigidity. The width is configured at 60%-90% of the inner diameter, maximizing the radial heat transfer area. The height is 50%-75% of the chamber height, ensuring effective heat transfer penetration depth.

[0067] The metal particle size is controlled within a range of 1%-5% of the chamber diameter. This size design ensures both sufficient particle suspension and adequate specific surface area. The addition amount is configured at a ratio of 5%-20% of the wastewater volume, achieving a balance between enhanced heat transfer and flow resistance.

[0068] Each component is designed proportionally based on the 16-core size of the cryogenic chamber, and this mesoscale correlation ensures the performance consistency of devices of different specifications. Metal rods serve as the heat transfer backbone, metal sheets achieve radial expansion, and metal particles fill the heat transfer gaps; together, these three elements construct a complete bulk heat transfer network.

[0069] In one embodiment, the multidimensional thermal bridge unit 15 is equipped with a vortex stirring unit 11, including an anchor or propeller-type stirring paddle and a variable frequency motor. The stirring paddle is made of polypropylene or stainless steel and its diameter is less than or equal to 60% of the inner diameter of the freezing chamber 16.

[0070] The stirring speed is dynamically adjusted according to the particle size of the metal particles. When the particle size is less than or equal to 2% of the inner diameter of the freezing chamber 16, the speed is 200 to 300 rpm. When the particle size is greater than 2% of the inner diameter of the freezing chamber 16, the speed is 50 to 150 rpm.

[0071] In one embodiment, the intelligent temperature field monitoring system includes multiple PT100 platinum resistance temperature sensors with a measurement accuracy of ±0.1 degrees Celsius, which are inserted into the solution at positions of 10% of the height from the bottom, 50% of the height, and 10% of the height from the surface.

[0072] In this embodiment, a PT100 platinum resistance temperature sensor is used, ensuring a measurement accuracy of ±0.1 degrees Celsius, providing a reliable data foundation for temperature field control. This high-precision monitoring can accurately capture minute temperature changes within the solution, creating conditions for subsequent precise control.

[0073] Sensors were placed at three key locations: 10% from the bottom of the solution, 50% from the middle, and 10% from the surface, forming a complete axial temperature gradient monitoring network. This placement method can simultaneously capture the temperature characteristics of the unfrozen bottom zone, the phase transition zone in the middle, and the surface ice crystal growth zone, comprehensively reflecting the dynamic changes in the freezing process.

[0074] The real-time acquired axial temperature distribution data provides accurate feedback signals to the refrigeration control system, enabling it to dynamically adjust the refrigeration intensity based on the actual temperature gradient. This control strategy based on measured data effectively avoids the problems of over-freezing or under-freezing in traditional methods.

[0075] By continuously monitoring the temperature at key locations, abnormal fluctuations in the temperature field can be detected and corrected in a timely manner, ensuring the stability of ice crystal growth and the continuity of copper ion migration paths, thus providing a guarantee for obtaining stable treatment results.

[0076] This temperature monitoring solution, through the combination of high-precision sensing and optimized point placement, enables precise monitoring of the freeze-concentration process, providing crucial support for the stable operation and performance optimization of the entire system.

[0077] In one embodiment, the heat insulation chamber 14 and the temperature control and acquisition system 12 are provided with a 40 mm to 60 mm thick polystyrene foam insulation layer on the side wall and an 80 mm to 120 mm thick polystyrene foam insulation layer at the bottom, with a thermal conductivity of less than or equal to 0.03 W / m Kelvin.

[0078] In this embodiment, the differentiated thickness design of 40-60 mm on the sidewalls and 80-120 mm on the bottom is specifically designed to block the loss of cold energy in different directions. The low thermal conductivity of polystyrene foam material, which is less than or equal to 0.03 W / m Kelvin, effectively reduces the heat transfer rate. The thickened bottom treatment compensates for the heat loss caused by contact conduction, making the temperature distribution in the chamber more uniform. This configuration reduces energy consumption while maintaining the stability of the low-temperature environment, and provides reliable protection for temperature-sensitive processes.

[0079] One embodiment of the present invention provides a method for treating copper-containing wastewater, which is implemented based on the copper-containing wastewater treatment method described in the above embodiment, and includes the following steps:

[0080] Wastewater pretreatment steps include filtering copper-containing wastewater and adjusting the pH value;

[0081] The device commissioning steps include selecting and installing the appropriate multidimensional thermal bridge unit 15;

[0082] The feeding process includes injecting wastewater into the refrigeration chamber 16;

[0083] The system startup and control steps include starting the refrigeration control system and the intelligent temperature field monitoring system to control the temperature gradient;

[0084] The freeze concentration step includes maintaining a freeze environment to allow copper ions to migrate and accumulate in a directional manner;

[0085] The concentrated liquid 18 collection step includes collecting the bottom concentrated liquid 18.

[0086] The present invention discloses a copper-containing wastewater treatment method that integrates six steps: wastewater pretreatment, device commissioning, feeding, system startup and control, freeze concentration, and collection of concentrated liquid. This system constructs a complete and coordinated treatment process, achieves standardized operation and precise temperature field control, effectively promotes the synergistic enhancement of heat and mass transfer, thereby improving the efficiency of copper ion directional migration and enrichment. At the same time, it optimizes resource recovery and process energy consumption, demonstrating the advantages of high efficiency, stability, and environmental protection.

[0087] In one embodiment, during the debugging process, wastewater is first injected, and pre-cooled metal particles are gradually added according to the freezing rate during the freezing process.

[0088] The pre-freezing temperature is between -25°C and -5°C to form a local low-temperature core to increase the migration rate of copper ions, or a combination of metal rods, sheets or granules can be selected according to the initial concentration of wastewater and the scale of treatment.

[0089] In this embodiment, the commissioning step involves first introducing pre-frozen metal particles and then injecting wastewater. This allows the low-temperature particles, ranging from -25°C to -5°C, to rapidly form multiple local low-temperature nuclei in the wastewater. These low-temperature nuclei effectively reduce the initial temperature of the surrounding solution, establishing a microscopic temperature gradient in advance and creating conditions for the full activation of the subsequent thermophoretic effect. The introduction of pre-frozen particles changes the traditional freezing process's heat transfer mode, which starts from the boundary, and enables rapid nucleation emanating from the interior of the solution phase. This shortens the time required for the system to reach a stable temperature field and promotes the directional migration of copper ions to the unfrozen region.

[0090] In one embodiment, during the freeze concentration step, the bulk heat transfer network constructed by the multidimensional thermal bridge unit 15 creates a uniform temperature gradient in the solution. Copper ions migrate to the unfrozen region under the drive of thermophoretic force, while the ice crystal displacement effect compresses the migration space of copper ions, thereby achieving efficient concentration and recovery of copper ions.

[0091] In this embodiment, a bulk heat transfer network constructed by the multidimensional thermal bridge unit 15 achieves a uniform temperature field distribution, enabling the solution to form a stable axial temperature gradient. Based on this temperature gradient, thermophoretic force drives copper ions to migrate directionally to the unfrozen region, while the displacement effect during ice crystal growth further compresses the ion migration space. The synergistic effect of these two mechanisms creates a concentration gradient amplification effect, thereby improving the concentration efficiency and recovery rate of copper ions.

[0092] In one embodiment, the filtration process in the wastewater pretreatment step includes filtering copper-containing wastewater using a 0.45-micron filter membrane to remove suspended particulate matter with a particle size greater than 1 micron, with an initial copper ion concentration of 100 mg / L to 500 mg / L.

[0093] In this embodiment, the pretreatment step effectively removes suspended particulate matter larger than 1 micrometer by using a 0.45-micrometer filter membrane, avoiding clogging of the thermal bridge unit gaps during subsequent processing and ensuring the smooth flow of the heat transfer network. Controlling the initial copper ion concentration within the range of 100-500 mg / L provides suitable initial conditions for the freeze-concentration process, ensuring processing efficiency while avoiding abnormal ice crystal growth caused by excessively high concentrations.

[0094] Furthermore, the stirring speed of the vortex stirring unit 11 is dynamically adjusted according to the particle size of the metal particles: when r≤D×2%, the speed is 200-300rpm (to avoid particle sedimentation); when r>D×2%, the speed is 50-150rpm (to prevent particle collision and damage to the chamber).

[0095] Based on the above-mentioned device, the core mechanism is: thermal resistance reconstruction - thermophoretic amplification - ice crystal displacement synergy, and the specific steps are as follows:

[0096] 1. Wastewater pretreatment: Filter copper-containing wastewater using a 0.45μm filter membrane to remove suspended particles with a diameter >1μm (to avoid clogging thermal bridge gaps), adjust the pH of the wastewater to 6.0-7.0 (to optimize the copper ion migration environment), and prepare wastewater to be treated with an initial copper ion concentration of 100-500mg / L;

[0097] 2. Adaptation and debugging of multi-dimensional thermal bridge unit 15: Based on the dimensions D and H of the freezing chamber 16, determine the key parameters (diameter / thickness / particle size, length / height, and spacing) of the axial / radial / mesoscale thermal bridges according to the mesoscale ratio. Fix the axial / radial thermal bridges to the freezing chamber 16 using anti-interference fixing brackets, ensuring that the immersion end is 5-10mm from the bottom. For the metal particle system, the mesoscale thermal bridge particles need to be pre-frozen to -25℃ to -5℃ (to form an initial low-temperature core and stimulate thermophoresis). Install the vortex stirring unit 11 and adjust the rotation speed according to the particle size.

[0098] 3. Feeding and pre-equilibrium: The pretreated wastewater is injected into the freezing chamber 16 (80%-90% of the volume). The pre-frozen mesoscale thermal bridge particles are first added to the metal particle system and left to stand for 5-10 minutes to achieve pre-distribution of the thermal field between the thermal bridge unit and the wastewater, laying the foundation for the subsequent construction of the heat transfer network.

[0099] 4. Coupled Enhanced Freeze-Concentration: The freeze control system and the intelligent temperature field monitoring system are activated. The low-temperature constant temperature chamber provides cold energy. The axial thermal bridge (metal rod) acts as the "main trunk of cold energy conduction" to capture cold energy and transfer it to the bulk solution phase. The radial thermal bridge (metal sheet) diffuses the cold energy laterally. The mesoscale thermal bridge (metal particles) fills the heat transfer gaps, forming a three-dimensional heat transfer network, reconstructing the thermal resistance distribution of the solution, and controlling the temperature gradient to ≤3℃. At this time, a stable axial temperature gradient is formed in the solution, which stimulates the "thermophoresis effect" (copper ions migrate to the low-temperature region under the drive of the temperature gradient). At the same time, ice crystals grow from the solution surface and the surface of the thermal bridge, producing the "ice crystal repulsion effect" (copper ions are repelled from the ice crystal lattice). The two work together to make copper ions migrate directionally to the bottom unfrozen region.

[0100] 5. Process maintenance in different modes: The static system (metal rod / plate) is frozen for 25-35 hours, relying on a three-dimensional heat transfer network to achieve uniform freezing; the dynamic system (metal particles + vortex stirring) is frozen for 20-30 hours, and the vortex stirring generates micro-convection, further enhancing the synergistic effect of thermophoresis-ice crystal displacement and accelerating copper ion migration; during this period, the temperature gradient is monitored in real time through an intelligent temperature field monitoring system, and the change in copper ion concentration is monitored through the sampling port.

[0101] 6. Targeted collection of concentrated liquid 18: After freezing is completed, shut down the system and wait for 20%-30% of the ice layer to melt (retain most of the ice crystals to avoid copper ion backflow). Open the drain valve at the bottom of the freezing chamber 16 and collect the high-concentration copper ion concentrated liquid 18 (concentration ≥1600mg / L) to complete the resource-based treatment of copper-containing wastewater.

[0102] Furthermore, the cryogenic chamber 16 is a low-temperature phase change reaction device that provides a sealed space for the cryogenic concentration of copper-containing wastewater, thereby achieving effective separation of copper ions and water resources. This chamber is typically made of corrosion-resistant, low-thermal-conductivity materials, and in conjunction with the insulated chamber 14 and the temperature control and acquisition system 12, it reduces cold loss. By precisely controlling the temperature and the distribution of the metallic medium within the chamber, the cryogenic chamber 16 can improve the selectivity and efficiency of cryogenic concentration. In this invention, the directional concentration of copper ions is achieved through the cryogenic chamber 16, and the presence of the highly thermally conductive metallic medium prevents copper ions from being trapped by ice crystals, reducing resource waste and improving the stability and reliability of the system.

[0103] A high thermal conductivity metallic dielectric component is connected to the freezing chamber 16. This component helps reduce the temperature gradient inside and outside the solution during freezing. During freeze-concentration, the ratio of copper ions to water in the solution gradually changes as the wastewater concentration reaction continues, directly causing fluctuations in concentration efficiency. Specifically, as water gradually freezes, the concentration of copper ions in the solution increases, making the mass transfer kinetics of the reaction system more complex and reducing the copper ion migration rate. Therefore, to maintain a sufficient migration rate, enhanced heat transfer is usually required to compensate. However, if the operating conditions for this enhanced heat transfer are not properly controlled, it can lead to an uneven temperature gradient in the solution. This not only affects the reaction kinetics but may also negatively impact the stability of ice crystal growth, thus affecting the long-term performance of the overall system.

[0104] By incorporating high thermal conductivity metallic media components, the temperature gradient between the inside and outside of the solution can be effectively reduced, thereby protecting the stability of ice crystal growth and extending the service life of the freezing chamber 16. Furthermore, a uniform temperature gradient helps improve concentration efficiency, allowing a high copper ion migration rate to be maintained with lower energy consumption. These comprehensive measures not only optimize the overall performance of cryogenic concentration but also improve the system's economy and sustainability.

[0105] A temperature acquisition system is connected to the freezing chamber 16 to monitor the temperature of the liquid inside. The liquid storage unit includes a raw material tank and a concentrate collection tank. The raw material tank is connected to the inlet of the freezing chamber 16 and is used to collect and store the copper-containing wastewater to be treated. The concentrate collection tank is connected to the outlet of the freezing chamber 16 and is used to collect and store the concentrated copper-containing concentrate 18. A flow meter is connected to the raw material tank, the concentrate collection tank, and the freezing chamber 16, and is used to control the flow rate of the liquid entering the freezing chamber 16.

[0106] The refrigeration control system is connected to the refrigeration chamber 16 and the temperature acquisition system. In particular, the refrigeration control system of the present invention is a combination of a low-temperature constant temperature chamber and a temperature controller, wherein the temperature controller is a frequency converter, which can dynamically adjust the refrigeration intensity according to the signal from the temperature acquisition system.

[0107] The surface trenches of the high thermal conductivity metallic dielectric components and the freezing chamber 16 can have different trench textures. Different trench textures have different heat transfer enhancement effects. The specific etched trench textures can be determined according to the actual application. This invention does not impose specific limitations, but the etching of different trench textures should all be within the protection scope of this invention. For example:

[0108] (1) Linear texture: Increases surface area by creating elongated grooves that are evenly distributed along the surface. This helps guide fluid flow, transforming laminar flow near the surface into turbulent flow, thereby enhancing heat exchange.

[0109] (2) Dotted texture: By creating multiple small protrusions, the micro-roughness of the surface is increased. This texture can effectively promote the formation of more vortices on the surface of the fluid, improve the mixing of the flow, and thus enhance the efficiency of convective heat transfer.

[0110] (3) Ripple texture: including wave-like undulations, which can increase the contact area of ​​the fluid and generate periodic pressure changes when the fluid flows through, thereby promoting turbulence. This structure can prolong the residence time of the fluid at the heat transfer interface and enhance heat transfer.

[0111] (4) Honeycomb texture: Simulates the honeycomb structure in nature, providing multiple flow paths, which helps to increase the surface area and effectively disperse fluid flow. This texture can increase the flow rate of the fluid and enhance the heat exchange effect.

[0112] (5) Textured surface: By creating an irregular surface structure, tiny depressions and protrusions are formed, increasing the contact area between the surface and the fluid. This texture helps to disrupt laminar flow and promote turbulence, thereby improving heat transfer efficiency.

[0113] Understandably, after filtering the copper-containing wastewater, it is injected into the raw material tank and the backup storage tank respectively, and the liquid levels in the raw material tank and the backup storage tank are kept the same.

[0114] Maintaining the same liquid level in the raw material tank and the spare storage tank ensures a stable and uniform flow rate during feeding, preventing fluctuations in the feed rate due to different liquid levels, which could affect the freezing and concentration effect. It also maintains the system's hydraulic balance, prevents liquid level fluctuations from impacting the equipment, avoids negative pressure or overflow in pipelines, and improves operational safety.

[0115] Turn on the delivery pump and adjust the liquid flow rate into the freezing chamber 16 according to the flow meter reading to stabilize the liquid flow rate into the freezing chamber 16.

[0116] Understandably, ensuring a stable liquid flow rate into the freezing chamber 16 allows for consistent heat and mass transfer conditions during freezing, ensuring uniform ice crystal growth. Otherwise, flow rate fluctuations would lead to inconsistent residence times of the solution within the chamber, potentially causing over-freezing or under-freezing in localized areas, thus affecting the directional migration and concentration of copper ions.

[0117] When the liquid flow rate in the freezing chamber 16 is stable, the freezing control system and temperature acquisition system are turned on.

[0118] Under the influence of the freezing environment, the high thermal conductivity metal dielectric components construct a low thermal resistance heat transfer path, so that the solution in the freezing chamber 16 forms a stable temperature gradient, which promotes the migration and enrichment of copper ions to the bottom unfrozen area.

[0119] When the temperature sensor detects that the liquid temperature in the freezing chamber 16 has reached the preset temperature, the freezing intensity is dynamically adjusted by the freezing control system to ensure that the liquid temperature in the freezing chamber 16 does not exceed the safe temperature, thus ensuring the directional migration of copper ions.

[0120] In summary, the apparatus and method for treating copper-containing wastewater using a high thermal conductivity metallic medium-enhanced progressive freeze-thaw concentration method described in this invention effectively avoids the generation of secondary pollution during the treatment of copper-containing wastewater. Relying on cold energy to drive the phase change reaction, it eliminates the need for additional chemical agents, thus reducing pollutant generation and environmental burden. It also significantly improves the corrosion resistance and stability of the freezing chamber 16, extends the equipment's service life, simplifies the wastewater treatment process, and effectively reduces operating and maintenance costs. Furthermore, this apparatus monitors the temperature of the liquid in the freezing chamber 16 using a temperature acquisition system. When the liquid temperature gradient is too large, the stirring unit is activated or the freezing intensity is adjusted to regulate the solution temperature gradient. Specifically, the surfaces of the freezing chamber 16 and the high thermal conductivity metallic medium components are engraved with grooves to enhance heat transfer, improving the heat transfer effect and ensuring the stability of ice crystal growth and concentration efficiency.

[0121] This invention can also dynamically adjust the output of the refrigeration control system based on real-time temperature information monitored by the temperature acquisition system, thereby optimizing the working state of the device. This precise temperature gradient control method not only ensures stable operation of the refrigeration concentration process within the set temperature range, but also increases the heat transfer intensity to improve concentration efficiency when needed, thereby improving the overall energy efficiency of the system. While reducing the temperature gradient, it also ensures a high-efficiency copper ion concentration rate.

[0122] Specifically, the water quality data for the copper-containing wastewater to be treated are as follows: copper ion content of 100-500 mg / L, pH=6.0-7.0, sulfuric acid mass fraction of 0-5%, and freezing temperature of -25℃ to -5℃.

[0123] The steps for concentrating and intelligently controlling the temperature of the copper-containing wastewater are as follows:

[0124] First, the copper-containing wastewater is filtered. Then, using a raw material transfer pump, the wastewater is transported to the freezing chamber 16 at a flow rate of 0.5-2 m³ / h. Once the flow rate stabilizes, the freezing control system is activated. Due to the high thermal conductivity metal-based media components and the special structural design of the freezing chamber 16, a stable temperature field is formed within the chamber. Under the freezing environment, the water gradually freezes, and copper ions are driven to the unfrozen area. Due to the low thermal resistance path constructed by the high thermal conductivity metal-based media, the solution temperature gradient remains stable, and copper ions continue to migrate and accumulate at the bottom. The experimental conditions are: freezing temperature -15℃, two metal rods, initial copper ion content: 300 mg / L, and after 25-35 hours of cyclic freezing, the percentage of copper ions in the bottom concentrate 18 can reach over 85% of the total copper ion content, with a maximum of 92%. The liquid temperature of the circulating wastewater gradually decreases from 25℃ to around -15℃. The freezing temperature is positively correlated with the concentration efficiency, but excessively low temperatures can lead to rapid ice crystal growth that traps copper ions. This problem is solved by combining high thermal conductivity metal media components with a refrigeration control system. The combination can achieve higher concentration efficiency in a shorter time, which not only ensures the stability of ice crystal growth, but also improves the recovery rate of copper ions.

[0125] The method for treating copper-containing wastewater described in this invention not only achieves stable freezing of the solution in the freezing chamber 16, but also intelligently controls the temperature and enhances heat transfer during the freezing process to ensure high concentration efficiency, without the need to add chemical agents.

[0126] The raw material wastewater used in this invention is copper-containing industrial wastewater, the sources of which include, but are not limited to, electroplating wastewater, printed circuit board etching wastewater, or mine drainage. In addition to the copper ions to be recovered (concentration range of 100 mg / L to 500 mg / L), this wastewater typically also contains a certain amount of other metal ions, suspended particulate matter, and organic impurities. Before entering the treatment device, it must undergo pretreatment steps as described in the specific embodiments.

[0127] After the above-mentioned freeze-concentration process, the copper ion concentration in the purified liquid obtained from the melting of ice crystals (corresponding to Figure 17) is significantly reduced. Depending on the process conditions, the copper ion concentration can be reduced to below 1 mg / L, meeting industrial reclaimed water or specific discharge standards. At the same time, the concentrated liquid enriched with copper ions (corresponding to Figure 18) can then proceed to the subsequent resource recovery process.

[0128] It should be noted that when the stirring is started after inserting the metal rod, plate, and ball, eddies will be generated when the liquid flows due to the obstruction of the metal rod and plate; in particular, the metal ball will move violently under the drive of the stirring paddle, and it will also move axially and radially, reducing the temperature gradient and enhancing the intensity of the eddies.

[0129] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A copper-containing wastewater treatment device, characterized in that, It includes a freezing chamber (16), an insulated chamber (14), a multi-dimensional thermal bridge unit (15), a temperature field intelligent monitoring system, a liquid storage unit, a freezing control system, and auxiliary structures; The heat insulation chamber (14) is fitted outside the freezing chamber (16), the multidimensional thermal bridge unit (15) is set inside the freezing chamber (16), the temperature field intelligent monitoring system is coupled to the freezing chamber (16), the liquid storage unit is connected to the freezing chamber (16), the freezing control system is connected to the temperature field intelligent monitoring system, and the auxiliary structure is used for fixing and sealing. The multidimensional thermal bridge unit (15) is made of a high thermal conductivity metal material and is used to reconstruct the heat transfer path of the solution phase and break the interface heat transfer limitation through the synergistic effect of thermal bridge and disturbance.

2. The copper-containing wastewater treatment device as described in claim 1, characterized in that, The high thermal conductivity metal material is one or more of 304 stainless steel, copper, titanium and aluminum, and its surface is covered with a gradient corrosion-resistant coating of silicon nitride or aluminum oxide, with the coating thickness to the medium size ratio being 1:100 to 1:

50.

3. The copper-containing wastewater treatment device as described in claim 1, characterized in that, The freezing chamber (16) is cylindrical with an inner diameter of 50 mm to 100 mm and a height of 100 mm to 200 mm; The multidimensional thermal bridge unit (15) includes one or more of metal rods, metal sheets and metal particles. The diameter of the metal rod is 1% to 8% of the inner diameter of the freezing chamber (16), and the total length is 50% to 150% of the height of the freezing chamber (16). When there are multiple metal rods, they are arranged in an equilateral triangle or a ring. The thickness of the metal sheet is 0.5% to 3% of the height of the freezing chamber (16), the width is 60% to 90% of the inner diameter of the freezing chamber (16), and the height is 50% to 75% of the height of the freezing chamber (16). The particle size of the metal particles is 1% to 5% of the inner diameter of the freezing chamber (16), and the amount added is 5% to 20% of the wastewater volume.

4. The copper-containing wastewater treatment device as described in claim 1, characterized in that, The multidimensional thermal bridge unit (15) is equipped with a vortex stirring unit (11), including an anchor or propeller stirring paddle and a variable frequency motor. The stirring paddle is made of polypropylene or stainless steel and its diameter is less than or equal to 60% of the inner diameter of the freezing chamber (16). The stirring speed is dynamically adjusted according to the particle size of the metal particles. When the particle size is less than or equal to 2% of the inner diameter of the freezing chamber (16), the speed is 200 to 300 revolutions per minute. When the particle size is greater than 2% of the inner diameter of the freezing chamber (16), the speed is 50 to 150 revolutions per minute.

5. The copper-containing wastewater treatment device as described in claim 1, characterized in that, The intelligent temperature field monitoring system includes multiple PT100 platinum resistance temperature sensors with a measurement accuracy of ±0.1 degrees Celsius, which are inserted into the solution at positions of 10% of the height from the bottom, 50% of the height, and 10% of the height from the surface.

6. The copper-containing wastewater treatment device as described in claim 1, characterized in that, The sidewalls of the insulation chamber (14) are provided with a polystyrene foam insulation layer of 40 mm to 60 mm thickness, and the bottom is provided with a polystyrene foam insulation layer of 80 mm to 120 mm thickness, with a thermal conductivity of less than or equal to 0.03 W / m Kelvin.

7. A method for treating copper-containing wastewater, characterized in that, Based on the device described in claim 1, the following steps are included: Wastewater pretreatment steps include filtering copper-containing wastewater and adjusting the pH value; The device commissioning steps include selecting and installing a suitable multidimensional thermal bridge unit (15). The feeding process includes injecting wastewater into the refrigeration chamber (16). The system startup and control steps include starting the refrigeration control system and the intelligent temperature field monitoring system to control the temperature gradient; The freeze concentration step includes maintaining a freeze environment to allow copper ions to migrate and accumulate in a directional manner; The concentrate (18) collection step includes collecting the bottom concentrate (18).

8. The method for treating copper-containing wastewater as described in claim 7, characterized in that, In the debugging device steps, wastewater is first injected, and during the freezing process, pre-cooled metal particles are gradually added according to the freezing rate. The pre-freezing temperature is between -25°C and -5°C to form a local low-temperature core to increase the migration rate of copper ions, or a combination of metal rods, sheets or granules can be selected according to the initial concentration of wastewater and the scale of treatment.

9. The method for treating copper-containing wastewater as described in claim 7, characterized in that, In the freeze concentration step, the bulk heat transfer network constructed by the multidimensional thermal bridge unit (15) enables the solution to form a uniform temperature gradient. Copper ions migrate to the unfrozen area under the drive of thermophoretic force, while the ice crystal displacement effect compresses the migration space of copper ions, thereby achieving efficient concentration and recovery of copper ions.

10. A method for treating copper-containing wastewater as described in claim 7, characterized in that, The filtration process in the wastewater pretreatment step includes filtering copper-containing wastewater using a 0.45-micron filter membrane to remove suspended particulate matter with a particle size greater than 1 micron, with an initial copper ion concentration of 100 mg / L to 500 mg / L.

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