Method for high-efficiency low-temperature heat pump evaporation treatment of waste liquid after mixing of brown solution and copperizing solution

Abstract

The application discloses a brown liquid and copper liquid mixed waste liquid efficient low-temperature heat pump evaporation treatment method, relates to the technical field of electroplating wastewater treatment, and specifically comprises the following steps: firstly, the brown waste liquid and the copper waste liquid are mixed through a synergistic matching algorithm, ferrous sulfate is added to decompose residual hydrogen peroxide, and then the mixture is concentrated through vacuum low-temperature heat pump evaporation; secondly, intermittent feeding and circulating evaporation are combined to carry out secondary crystallization and drying, and the drying state is controlled by using an end point prediction algorithm; finally, condensed liquid and high-copper-content crystalline substances are separated and recovered; the brown waste liquid and the copper waste liquid are spontaneously and synergistically mixed, no external reagent is needed, low-temperature heat pump evaporation and real-time foam control are combined, energy consumption and safety risks are reduced; the intermittent feeding, circulating evaporation and end point prediction algorithm are combined to accurately dry the mixture, form dense copper salt crystalline, and recycle the condensed liquid for reuse, so that copper resources are efficiently recycled and water resources are recycled, and an energy-saving, environment-friendly and low-cost closed-loop treatment process is constructed.

Description

Technical Field

[0001] This invention relates to the field of electroplating wastewater treatment technology, specifically a method for efficient low-temperature heat pump evaporation treatment of waste liquid after mixing browning solution and copper plating solution. Background Technology

[0002] In the fields of electronics manufacturing and electroplating, browning and copper plating processes are core steps in ensuring product quality. These processes continuously generate large quantities of browning and copper plating wastewater. This wastewater contains metal ions, complex components, and oxidizing and reducing substances, exhibiting complex composition and hazardous waste characteristics. Indiscriminate discharge can cause irreversible damage to the water and soil environment, while also resulting in the significant loss of valuable metal resources. With the increasing emphasis on national ecological and environmental protection and the ongoing promotion of industrial resource recycling policies, the harmless treatment and resource recovery of electroplating wastewater have become essential prerequisites for industry development. Low-temperature heat pump evaporation technology, with its advantages of mild processing conditions and low energy consumption, has become the mainstream technology for wastewater treatment. However, the industry currently lacks a dedicated solution for the mixed treatment of browning and copper plating wastewater. Problems such as unscientific mixing ratios, incomplete pretreatment, and crude control of evaporation and drying are common, making it difficult to achieve stable, efficient, and compliant treatment of mixed wastewater.

[0003] Traditional electroplating mixed wastewater treatment technologies have many limitations, failing to adapt to the treatment characteristics of brown plating wastewater and copper plating wastewater. The overall treatment effect and operational efficiency are insufficient to meet industry needs. Conventional chemical treatment methods can only perform simple neutralization and precipitation of the wastewater, failing to effectively break down the complex structures within the wastewater. Metal ion removal is incomplete, resulting in water quality that fails to meet standards and generating large amounts of difficult-to-dispose-of sludge, increasing subsequent treatment costs and environmental risks. Traditional evaporation treatment often employs high-temperature conditions, leading to huge energy consumption and high operating costs. Furthermore, the high-temperature environment easily causes the release of volatile substances from the wastewater, causing secondary pollution. Simultaneously, traditional processes lack targeted pretreatment steps, allowing unstable residual components in the wastewater to undergo side reactions during treatment, affecting system stability. The crystallization and drying stages lack precise control methods, resulting in low resource recovery purity and efficiency. Insufficient process continuity and automation make it unsuitable for large-scale industrial processing. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a high-efficiency, low-temperature heat pump evaporation method for treating waste liquid from the mixing of browning solution and copper melting solution. This method first determines the optimal mixing ratio of the two waste liquids using a synergistic proportioning algorithm. After mixing, ferrous sulfate is added to decompose residual hydrogen peroxide, resulting in a pretreated waste liquid. Subsequently, continuous evaporation and concentration are carried out under vacuum and low-temperature conditions, followed by a second low-temperature crystallization and drying process combined with intermittent feeding and circulating evaporation. During this process, an endpoint prediction algorithm is used to control the moisture content of the material in real time. Finally, the condensate and high-copper-content crystals are separated and recovered, achieving the resource recovery of valuable copper salts from the waste liquid.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for efficient low-temperature heat pump evaporation treatment of waste liquid after mixing browning solution and copper melting solution, the specific steps of which are as follows: S100, waste liquid ratio mixing: browning waste liquid and copper plating waste liquid generated in electroplating production are collected in a closed system. The optimal volume mixing ratio of the waste liquid is determined by the collaborative ratio algorithm. The two waste liquids are metered and transported into the container according to the ratio, stirred and mixed thoroughly, and the spontaneous reaction is completed. After standing and stabilizing, a mixed raw material liquid with uniform properties is obtained. S200, hydrogen peroxide removal: Add the specified amount of ferrous sulfate evenly to the static and stable mixed raw material liquid, keep stirring to ensure that the agent is in full contact with the waste liquid, and completely decompose the residual hydrogen peroxide in the waste liquid to obtain a stable pretreated waste liquid. S300, Low-temperature concentration: The pretreated waste liquid is placed in a vacuum low-temperature environment for continuous evaporation, and the foam on the liquid surface is monitored in real time and eliminated in time, so that the waste liquid reaches the set concentration level and forms a high-concentration concentrate. S400 Crystallization and Drying: High-concentration concentrate is subjected to secondary low-temperature treatment by a combination of intermittent feeding and circulating evaporation. The drying state of the material is controlled by the endpoint prediction algorithm throughout the process. After the material reaches the drying requirements, it is discharged while hot. The discharged material gradually solidifies and hardens after natural cooling, forming copper salt crystals. S500, Product Separation and Reuse: Collect all the condensate generated during the low-temperature concentration and crystallization drying process, and reuse it after simple treatment. Seal and collect the cooled high-copper-content dried crystallized material.

[0006] Furthermore, the browning waste liquid and copper-plating waste liquid are mixed by low-speed constant stirring. The stirring operation lasts for no less than 30 minutes, and the stirring speed is set to 120 r / min to 180 r / min. After stirring, the settling time is 60 minutes to 90 minutes. No external acid-base regulators or redox agents are added during the mixing process. The waste liquid completes the entire spontaneous reaction process by relying on its own physicochemical properties.

[0007] Furthermore, the mathematical expression for the synergistic proportioning algorithm is: ; Among them, R opt Characterizes the optimal volumetric mixing ratio of browning waste liquid and copper melting waste liquid, used to directly guide the metering and mixing operations of browning waste liquid and copper melting waste liquid; K c This is a comprehensive process correction factor, ranging from 0.95 to 1.05. It is calibrated based on the actual evaporation efficiency of the wastewater treatment equipment, the characteristics of the production water quality in the plant area, and the on-site working conditions, to adapt to fluctuations in operating conditions for different production batches; K L The average stability constant of the complexed copper in the mixed liquid system is calculated by weighting the actual concentrations of EDTA and HEDP complexing agents in the mixed liquid, and is used to characterize the binding stability of complexed copper ions in the mixed system; A1 is the total acidity of the browning waste liquid, in mol / L, expressed as H+ ions in the system. + The total molar concentration meter is used to quantify the total content level of acidic components in browning wastewater; B2 is the total alkalinity of copper leaching wastewater, in mol / L, expressed as ionizable hydroxide ions (OH-) within the system. - The total molar concentration is used to quantify the total content level of alkaline components in copper-containing waste liquid; O1 is the total oxidation capacity of the copper-containing waste liquid, in mol / L, expressed as the equivalent molar concentration of hydrogen peroxide (H2O2) in the system, used to uniformly quantify the total reaction equivalent of various oxidizing substances in the copper-containing waste liquid; R2 is the total reducing capacity of the copper-containing waste liquid, expressed as the equivalent molar concentration of formaldehyde (HCHO) in the system, used to characterize the overall reducing reaction activity of the copper-containing waste liquid.

[0008] Furthermore, the added ferrous sulfate is anhydrous ferrous sulfate solid powder. The dosage is calculated based on the volume of the mixed raw material liquid, with 0.8g of anhydrous ferrous sulfate added per liter of mixed raw material liquid. The addition method is to use a screw feeder to add the ferrous sulfate at a uniform speed. The stirring speed is set to 200r / min~250r / min, and the stirring reaction time is 40min~60min. During the reaction, the pH value in the container is maintained between 3.5 and 4.5, and the reaction temperature is controlled between 20℃ and 30℃. Before addition, the ferrous sulfate is dried to a moisture content below 0.5%. The addition process is uniform and uninterrupted to ensure that the reagent and the waste liquid are fully and evenly mixed. There is no local accumulation of reagent during the reaction process, and the reagent dispersion meets the requirements for uniform reaction of the waste liquid system.

[0009] Furthermore, the vacuum degree of the vacuum low-temperature environment is controlled between -0.07MPa and -0.09MPa, the evaporation temperature of the low-temperature heat pump is set to 45℃~55℃, the continuous evaporation time is 120min~180min, the liquid surface foam monitoring adopts a photoelectric monitoring probe with a monitoring frequency of 1 time / second, the foam elimination adopts a mechanical defoaming paddle with a defoaming paddle speed of 300r / min, the defoaming trigger threshold is when the liquid surface foam height exceeds 5cm, the concentration degree is set to 25% of the original pretreated waste liquid volume, and the concentrated liquid is transported through an insulated pipeline with the pipeline temperature maintained at 50℃ to prevent premature crystallization of the concentrated liquid during transportation.

[0010] Furthermore, the secondary low-temperature treatment temperature is maintained at 40℃~50℃, the vacuum degree is controlled at -0.07MPa, the intermittent feeding amount is 15%~20% of the total mass of the high-concentration concentrate, each cycle of evaporation is 30min, the material drying state is determined in real time by the endpoint prediction algorithm, the determination cycle is 10s each time, and the material is discharged after the drying requirement of moisture content is lower than 8%, the material discharge temperature is controlled at 60℃~70℃, the discharged material is placed on a stainless steel cooling tray with a thickness of 2mm, the natural cooling environment temperature is 15℃~25℃, the cooling time is 120min~150min, the cooling process is carried out in a sealed dust-free environment, and finally a dense copper salt crystal material is formed.

[0011] Furthermore, the mathematical expression for the endpoint prediction algorithm is: ; Among them, W end The final moisture content of the dried material is the control target parameter for the crystallization drying process, which is collected in real time by an online moisture content sensor. The initial moisture content of the mixture formed after synergistic mixing is directly related to the optimal volume mixing ratio of the browning waste liquid and the copper melting waste liquid, and is collected by an online moisture content sensor at the end of the waste liquid mixing process; R opt The optimal volume mixing ratio of browning waste liquid and copper leaching waste liquid; k e The low-temperature evaporation rate constant is calibrated in advance based on the equipment's evaporation efficiency and waste liquid characteristics, with a value range of 0.001 to 0.005. The parameter is updated once before each batch of waste liquid is treated to match the evaporation characteristics of different batches of waste liquid. The initial viscosity of the mixture at the optimal mixing ratio is given in mPa·s, and is related to R. opt Directly related, the viscosity is collected by an online viscosity sensor at the end of the waste liquid proportioning and mixing process, with a collection accuracy of ±0.1 mPa.s, reflecting the flow characteristics of the mixture in its initial state; T represents the real-time viscosity of the material during the crystallization and drying process, measured in mPa·s. This viscosity is collected every 5 seconds by an online viscosity sensor within the crystallization and drying process, reflecting the dynamic changes in the material's flow characteristics during drying. T represents the actual evaporation temperature, measured in °C. This temperature is collected in real-time by a temperature sensor within the crystallization and drying process, reflecting the actual heating state of the material during the secondary low-temperature treatment. ref The preset reference evaporation temperature, in °C, is a process parameter for the crystallization and drying process, ranging from 45°C to 60°C. It matches the evaporation temperature setting of the low-temperature concentration step, providing a reference temperature for the algorithm calculation. P represents the actual vacuum level, in MPa, which is collected in real-time by a vacuum pressure sensor within the crystallization and drying process, reflecting the actual vacuum state of the system during the secondary low-temperature treatment. ref The preset reference vacuum degree, in MPa, is a process setting parameter for the crystallization and drying process, with a value range of -0.07MPa to -0.095MPa, providing a reference vacuum degree for algorithm calculation; t is the cumulative evaporation time of the material in the crystallization and drying process, in h, reflecting the duration of the material in the secondary low-temperature treatment state.

[0012] Furthermore, the condensate is collected in a sealed collection tank at atmospheric pressure. The condensate is then treated by a quartz sand filter with a filtration accuracy of 5μm to 10μm and a filtration flow rate of 1.2m³ / h to 1.5m³ / h. The treated condensate is then reused in the cleaning process of the electroplating production line, with the reuse conveying pressure controlled at 0.2MPa.

[0013] Furthermore, the high-copper-content dried crystallized material is collected in a sealed stainless steel storage tank with a volume of 200L. The filling amount of a single storage tank is controlled at 150kg. After collection, the storage tank is sealed with a lid, and the sealing pressure is maintained at 0.01MPa. The collection process is completed in a closed operating room with ventilation. The ventilation rate is set to 12 times / hour. After collection, the storage tank is sealed with a lid and labeled. The temperature of the storage area is controlled at 18℃~25℃, and the humidity is controlled at 45%~60%.

[0014] Compared with existing technologies, this efficient low-temperature heat pump evaporation treatment method for waste liquid after mixing browning solution and copper melting solution has the following advantages: I. This invention achieves a spontaneous reaction by synergistically mixing browning waste liquid and copper-plating waste liquid in an optimal ratio, relying on the inherent physicochemical properties of the waste liquids. This eliminates the need for external acids, alkalis, and redox agents, simplifying the waste liquid mixing pretreatment process and reducing reagent usage and costs. By selectively removing residual hydrogen peroxide from the waste liquid, the system becomes more stable, laying a solid foundation for subsequent evaporation treatment. Continuous concentration is achieved using a vacuum low-temperature heat pump evaporation mode, coupled with real-time foam monitoring and elimination methods, ensuring a smooth evaporation process. A synergistic proportioning algorithm adapts to fluctuations in different operating conditions, resulting in more precise mixing ratios. Low-temperature operation throughout reduces energy consumption and improves the energy efficiency of waste liquid treatment. Simultaneously, it avoids material deterioration and safety hazards caused by high-temperature treatment, making the waste liquid treatment process more continuous and adaptable to different operating conditions. This effectively reduces unstable factors during treatment and ensures consistent treatment results.

[0015] II. This invention employs a secondary low-temperature drying method combining intermittent feeding and circulating evaporation, coupled with an endpoint prediction algorithm to precisely control the material's drying state. This ensures that copper salt crystals form a dense and stable material morphology, improving the convenience of product collection and subsequent utilization. The condensate from the entire evaporation process is centrally recovered and reused after simple filtration, maximizing water resource recycling. High-copper-content crystalline materials are collected and stored in a sealed manner, achieving efficient copper resource recovery. The fully sealed and dust-free operation reduces the risk of secondary pollution from exhaust gases and dust, constructing a closed-loop process for wastewater treatment, resource recovery, and water reuse. This reduces the overall cost of wastewater treatment for electroplating enterprises while meeting environmental emission requirements, making wastewater treatment both environmentally and economically beneficial. The process is more reliable and suitable for large-scale industrial processing scenarios.

[0016] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A framework diagram of a high-efficiency low-temperature heat pump evaporation method for treating waste liquid after mixing browning solution and copper melting solution; Figure 2 A flowchart of a high-efficiency low-temperature heat pump evaporation treatment method for waste liquid after mixing browning solution and copper melting solution; Figure 3 This is a flowchart of the crystallization and drying steps of the present invention. Detailed Implementation

[0019] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0020] Example 1: This embodiment provides a complete standard operating procedure for the efficient low-temperature heat pump evaporation treatment method of waste liquid after mixing browning solution and copper melting solution, such as... Figure 1 As shown.

[0021] First, a waste liquid mixing step is performed. The browning waste liquid and copper plating waste liquid continuously produced from the printed circuit board electroplating production line are collected in a sealed container and temporarily stored in separate 5-cubic-meter PE sealed storage tanks. Each tank is equipped with a breather valve and a waste gas collection interface on its top. The optimal volume mixing ratio of the two waste liquids is calculated using a collaborative mixing algorithm. The mathematical expression for the collaborative mixing algorithm is: ; Among them, R opt Characterizing the optimal volume mixing ratio of browning waste liquid and copper leaching waste liquid; K c K is the overall process correction factor. L R1 represents the average stability constant of the complexed copper in the mixed liquid system; A1 represents the total acidity of the browning waste liquid; B2 represents the total alkalinity of the copper-based waste liquid; O1 represents the total oxidizing capacity of the browning waste liquid; R2 represents the total reducing capacity of the copper-based waste liquid; and K represents the process comprehensive correction coefficient in this embodiment. c Take 1.0, the average stability constant K of the complexed copper in the mixed liquid system. L Using a concentration of 1.2 × 10^16, the total acidity A1 of the browning waste liquid was 1.2 mol / L, the total alkalinity B2 of the copper-containing waste liquid was 0.8 mol / L, the total oxidizing capacity O1 of the browning waste liquid was 0.3 mol / L, and the total reducing capacity R2 of the copper-containing waste liquid was 0.2 mol / L, the optimal volume mixing ratio was calculated to be 6:1. According to this ratio, the two waste liquids were precisely pumped into a 3 cubic meter sealed reaction vessel using a metering pump. The stirring device was started and the mixture was stirred at a low and constant speed of 150 r / min for 45 minutes to ensure sufficient contact between the two waste liquids and to complete the spontaneous reaction. After stirring, the mixture was allowed to stand for 75 minutes to allow the system to stabilize fully, resulting in a homogeneous mixed raw material solution. No exogenous acid-base adjusters or redox agents were added during the entire mixing process; the reaction was carried out entirely by the physicochemical properties of the waste liquids themselves.

[0022] After mixing and stabilization, the hydrogen peroxide removal step begins. Anhydrous ferrous sulfate powder, pre-dried at 105℃ for 2 hours with a moisture content controlled at 0.3%, is added uniformly to the mixed raw material solution. The dosage is calculated at 0.8g of anhydrous ferrous sulfate per liter of mixed raw material solution. A screw feeder is used to continuously convey the solution at a rate of 0.5kg / min to ensure uniform dispersion. Simultaneously, a stirring device is activated and continuously stirred at 220r / min for 50 minutes to ensure sufficient contact and reaction between the ferrous sulfate and the mixed raw material solution, completely decomposing any residual hydrogen peroxide in the waste liquid. During the reaction, the pH value in the container is maintained at approximately 4.0, and the reaction temperature is controlled at 25℃ to prevent localized agent accumulation, ultimately yielding a stable pretreated waste liquid.

[0023] After pretreatment, the waste liquid enters a low-temperature concentration step. The pretreated waste liquid is then transported to a low-temperature heat pump evaporator. Once operational, the equipment establishes a stable vacuum environment, controlled at -0.08 MPa, with the evaporation temperature set at 50°C. The waste liquid is continuously evaporated for 150 minutes. During evaporation, a photoelectric monitoring probe monitors the foam state on the liquid surface in real time at a frequency of 1 time per second. When the foam height exceeds 5 cm, a mechanical defoaming paddle is immediately activated at a speed of 300 rpm to defoam, ensuring stable evaporation. Evaporation continues until the waste liquid volume is concentrated to 25% of the original pretreated waste liquid volume, forming a high-concentration concentrate. This concentrate is then transported to the next process via an insulated pipeline, with the pipeline temperature maintained at 50°C to prevent premature crystallization during transport.

[0024] The high-concentration concentrate enters the crystallization and drying step, employing a combination of intermittent feeding and circulating evaporation for secondary low-temperature treatment. The secondary low-temperature treatment temperature is maintained at 45℃, and the vacuum degree is controlled at -0.07MPa. The intermittent feeding rate is 18% of the total mass of the high-concentration concentrate per batch, and each cycle of circulating evaporation is 30 minutes. Throughout the process, the drying state of the material is determined every 10 seconds using an endpoint prediction algorithm. The mathematical expression for the endpoint prediction algorithm is: ; Among them, W end This refers to the final moisture content of the dried material. R represents the initial moisture content of the mixture formed after synergistic mixing; opt The optimal volume mixing ratio of browning waste liquid and copper melting waste liquid; k e This is the low-temperature evaporation rate constant; The initial viscosity of the mixture at the optimal mixing ratio; T represents the real-time viscosity of the material during the crystallization and drying process; T represents the actual evaporation temperature; T ref P is the preset reference evaporation temperature; P is the actual vacuum level; P refThe reference vacuum level is set in advance; t is the cumulative evaporation time of the material in the crystallization and drying process; and k is the low-temperature evaporation rate constant in this embodiment. e Take 0.003, with reference evaporation temperature T ref Take 45℃, and reference vacuum degree P. ref Use -0.07MPa. When the algorithm determines that the material moisture content is below 8%, the control equipment discharges the material while it is still hot, with the discharge temperature controlled at 65℃. The discharged material is conveyed to a 2mm thick stainless steel cooling tray and naturally cooled for 135 minutes in a sealed, dust-free environment at 20℃, gradually solidifying and hardening to form a dense copper salt crystal material, such as... Figure 3 As shown.

[0025] Finally, the product separation and reuse step is performed. The condensate generated during the entire low-temperature concentration and crystallization drying process is collected in a sealed collection tank with a volume of 10 cubic meters, and the tank operates at atmospheric pressure. The condensate is then filtered through a quartz sand filter with a filtration accuracy of 8μm and a filtration flow rate of 1.3 m³ / h. After treatment, the condensate is reused in the electroplating production line's cleaning process at a conveying pressure of 0.2 MPa. The cooled, high-copper-content dried crystallized material is then sealed and collected in a 200L stainless steel storage tank, with a single tank containing 150 kg. After collection, the storage tank is sealed, and the sealing pressure is maintained at 0.01 MPa. The collection process is completed in a closed operating room with an air exchange rate of 12 times / h. After collection, the storage tank is sealed and labeled. The storage area temperature is controlled at 22℃ and the humidity at 52%, completing the entire processing flow.

[0026] Example 2: This embodiment addresses the scenario of fluctuating production conditions in a factory area, providing an implementation process for a high-efficiency, low-temperature heat pump evaporation method for treating waste liquid resulting from the mixing of browning solution and copper plating solution. Figure 2 As shown.

[0027] During the waste liquid proportioning and mixing stage, the comprehensive process correction coefficient K of the collaborative proportioning algorithm is calibrated based on the actual water quality and equipment operating efficiency of the plant. c The value is 0.98. The total acidity A1 of this batch of browning waste liquid is 1.0 mol / L, the total alkalinity B2 of the copper-containing waste liquid is 0.7 mol / L, the total oxidizing capacity O1 of the browning waste liquid is 0.25 mol / L, the total reducing capacity R2 of the copper-containing waste liquid is 0.18 mol / L, and the average stability constant K of the complexed copper in the mixed liquid system is... LUsing 1.1 × 10^16, the optimal volume mixing ratio was calculated to be 5.8:1. After the browning waste liquid and copper-containing waste liquid were transported to the reaction vessel in a closed system, the stirring speed was controlled at 120 r / min, and the stirring time was 50 min to ensure uniform mixing. The settling time was 90 min. No additional chemical reagents were added. The reaction was carried out spontaneously by relying on the acid-base and redox properties to obtain a homogeneous and stable mixed raw material solution.

[0028] During the hydrogen peroxide decomposition stage, the moisture content of anhydrous ferrous sulfate was strictly controlled to 0.4%. Anhydrous ferrous sulfate was added at a dosage of 0.8 g per liter of mixed raw material solution using a screw feeder at a uniform rate of 0.4 kg / min. Simultaneously, the stirring speed was maintained at 200 r / min, the reaction time was 60 min, the pH of the reaction system was maintained at 3.5, and the reaction temperature was controlled at 20℃ to ensure complete decomposition of hydrogen peroxide, eliminate its adverse effects on subsequent vacuum evaporation, and improve the stability of the pretreated waste liquid.

[0029] During the low-temperature concentration stage, the vacuum level is finely adjusted to -0.07 MPa based on the ambient temperature, the evaporation temperature is set to 45℃, and the continuous evaporation time is 180 minutes. Foam monitoring and defoaming are performed simultaneously. A photoelectric monitoring probe monitors the liquid level at a frequency of 1 time per second. When the foam height exceeds 5 cm, a mechanical defoaming paddle is activated at a speed of 300 r / min to defoam. The high-concentration concentrate obtained after concentration is transported to the next process through an insulated pipeline. The pipeline temperature is maintained at 50℃ to prevent crystallization and blockage of the pipeline.

[0030] During the crystallization and drying stage, the temperature of the secondary low-temperature treatment was maintained at 40℃, and the vacuum degree was controlled at -0.07MPa. Intermittent feeding was used, with each feed amount being 15% of the total mass of the high-concentration concentrate. Each cycle of evaporation was 30 minutes. The endpoint prediction algorithm determined the material drying state every 10 seconds. In this embodiment, the low-temperature evaporation rate constant k... e Take 0.0025, with reference evaporation temperature T. ref Take 45℃, and reference vacuum degree P. ref Use -0.07 MPa. Discharge the material promptly when the moisture content is below 8%, and control the discharge temperature at 60℃. Allow the material to cool naturally for 150 minutes in a sealed, dust-free environment at 15℃ to form copper salt crystals.

[0031] In the product separation and reuse stage, the condensate is treated by a quartz sand filter with a filtration accuracy of 5μm and a filtration flow rate set at 1.2m³ / h. The treated water quality meets the reuse standards and is stably transported to the production cleaning stage at a conveying pressure of 0.2MPa. High copper-content crystal materials are collected and stored in a sealed manner throughout the process. The operating room maintains ventilation 12 times / h, and the temperature in the storage area is controlled at 18℃ and the humidity at 45% to ensure stable material quality.

[0032] Example 3: This embodiment provides an implementation process for a high-efficiency, low-temperature heat pump evaporation treatment method for waste liquid after mixing browning solution and copper plating solution in a continuous, large-scale production scenario.

[0033] During the waste liquid proportioning and mixing stage, an automated closed collection system is used to continuously collect browning waste liquid and copper plating waste liquid. A collaborative proportioning algorithm collects the physicochemical parameters of the waste liquid in real time and dynamically outputs the optimal mixing ratio. In this embodiment, the process comprehensive correction coefficient K c The total acidity and total oxidizing capacity of the browning waste liquid and the total alkalinity and total reducing capacity of the copper-containing waste liquid are automatically detected every 30 minutes, and the average stability constant K of the complexed copper in the mixed liquid system is updated in real time. L The metering pump's flow rate is dynamically adjusted to achieve automated metering, conveying, and mixing. The stirring speed is set to 180 r / min, the stirring time to 30 min, and the settling time to stabilize to 60 min. After the mixed system stabilizes, it automatically enters the next process, achieving continuous feeding.

[0034] During the hydrogen peroxide removal stage, an automated dosing system is used to deliver anhydrous ferrous sulfate. The moisture content of the dried ferrous sulfate is controlled below 0.5%. The dosage and dosing rate are matched with the feed flow rate in real time to ensure that 0.8 g of anhydrous ferrous sulfate is added per liter of mixed raw material liquid. The stirring speed is set to 250 r / min, the stirring reaction time is 40 min, the pH value of the reaction system is maintained at 4.5, and the reaction temperature is controlled at 30℃. The stirring state and reaction conditions are automatically controlled throughout the process to ensure complete hydrogen peroxide removal and stable output of pretreated waste liquid, meeting the requirements for continuous treatment.

[0035] During the low-temperature concentration stage, the low-temperature heat pump evaporator operates continuously for 24 hours, with the vacuum level controlled at -0.09 MPa, the evaporation temperature set at 55℃, and the continuous evaporation time at 120 minutes. Online foam monitoring and mechanical defoaming are linked for control; a photoelectric monitoring probe monitors the liquid level at a frequency of 1 time per second, automatically triggering defoaming action. The concentrated liquid is automatically transported to the crystallization and drying process, with the insulated conveying system maintaining a temperature of 50℃ to prevent crystallization and ensure smooth material transport.

[0036] During the crystallization and drying stage, an automatic control mode of intermittent feeding and circulating evaporation was adopted. The secondary low-temperature treatment temperature was maintained at 50℃, and the vacuum degree was controlled at -0.07MPa. The intermittent feeding amount was 20% of the total mass of the high-concentration concentrate, and each cycle of circulating evaporation was 30 minutes. The endpoint prediction algorithm collected the material moisture content, viscosity, temperature, and vacuum degree parameters in real time, and determined the drying state every 10 seconds. In this embodiment, the low-temperature evaporation rate constant k was used. e Take 0.004, with reference evaporation temperature T ref Take 50℃ and reference vacuum degree P. refSet the pressure to -0.07 MPa. When the material moisture content is below 8%, the discharge process is completed automatically, with the discharge temperature controlled at 70℃. The discharged material is automatically conveyed to the cooling area and naturally cooled for 120 minutes in a sealed, dust-free environment at 25℃ to complete solidification and crystallization.

[0037] In the product separation and reuse stage, the condensate is automatically collected, filtered, and reused, forming a closed-loop water resource system. The filtration accuracy is 10μm, the filtration flow rate is set at 1.5m³ / h, and the reuse conveying pressure is 0.2MPa. High-copper-content crystalline materials are automatically collected, sealed, and labeled for storage. The storage tank has a volume of 200L, the filling amount of a single storage tank is controlled at 150kg, and the sealing pressure is maintained at 0.01MPa. The entire process involves no direct human contact, reducing the risk of contamination and improving the efficiency and safety of large-scale processing.

[0038] Comparative Example In related technologies, traditional separate treatment methods are used to treat browning waste liquid and copper-plating waste liquid separately, without mixing and synergistic reaction, without using synergistic proportioning algorithm and endpoint prediction algorithm, and without using low-temperature heat pump evaporation and crystallization drying treatment.

[0039] Browning wastewater was treated separately using chemical precipitation. Sodium hydroxide solution was added to adjust the pH to 9.0, followed by the addition of sodium sulfide solution to precipitate copper ions as copper sulfide. The amount of sodium sulfide added was calculated based on a sulfide to copper ion molar ratio of 1.2:1. After stirring for 30 minutes, the mixture was allowed to settle for 2 hours, and then filtered to obtain copper sludge with a water content of approximately 75%. Copper oxide wastewater was treated separately using acidification and complex-breaking precipitation. Sulfuric acid was first added to adjust the pH to 2.0, followed by the addition of sodium hypochlorite for oxidation and complex-breaking. After complex-breaking, sodium hydroxide was added to adjust the pH to 9.0, and finally, sodium sulfide was added to precipitate copper sulfide, which was then filtered to obtain copper sludge.

[0040] Traditional treatment methods do not include hydrogen peroxide pretreatment. During evaporation, the hydrogen peroxide breaks down, generating a large amount of gas, leading to unstable equipment vacuum and severe foam overflow. High-temperature evaporation, set at 100℃ and operating at atmospheric pressure, is energy-intensive and prone to releasing harmful substances. It does not employ a combination of intermittent feeding and circulating evaporation; the degree of material drying relies on manual observation, resulting in unstable copper salt crystal quality with moisture content fluctuating between 15% and 25%. The condensate lacks efficient purification, resulting in high COD content, making stable reuse difficult and requiring further treatment at the plant's integrated wastewater treatment station. The overall process is cumbersome, with high equipment investment and operating costs. Copper resources are recovered as low-value copper sludge, requiring disposal by qualified companies, failing to achieve the synergistic goal of wastewater reduction and resource recovery.

[0041] Comparison Table of Key Processes and Effects between Examples and Comparative Examples To intuitively demonstrate the advantages of the technical solution of this invention, the core process parameters and processing effects of the three sets of embodiments and one set of comparative examples are systematically compared as follows: The above comparative results demonstrate that this invention, through its complete technical solution of synergistic mixing, hydrogen peroxide removal, low-temperature concentration, crystallization drying, and product separation and reuse, can stably and efficiently treat browning wastewater and copper leaching wastewater. Compared with traditional separate treatment methods, this invention can reduce chemical reagent consumption by approximately 70%, more than double the added value of copper resource recovery, reduce operating costs by approximately 40%, and simultaneously achieve stable reuse of condensate, exhibiting good industrial applicability and environmental benefits.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple 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 method for efficient low-temperature heat pump evaporation treatment of waste liquid after mixing browning solution and copper melting solution, characterized in that, The specific steps of this method are as follows: S100. Waste Liquid Proportioning and Mixing: Browning waste liquid and copper plating waste liquid generated during electroplating are collected in a closed system. The optimal volumetric mixing ratio of the waste liquids is determined using a collaborative proportioning algorithm. The two waste liquids are metered and transported into a container according to the ratio, thoroughly stirred, and allowed to undergo a spontaneous reaction. After settling and stabilizing, a homogeneous mixed raw material liquid is obtained. The mathematical expression of the collaborative proportioning algorithm is: ； Among them, R opt Characterizing the optimal volume mixing ratio of browning waste liquid and copper leaching waste liquid; K c K is the overall process correction factor. L R1 represents the average stability constant of the complexed copper in the mixed liquid system; A1 is the total acidity of the browning waste liquid; B2 is the total alkalinity of the copper-containing waste liquid; O1 is the total oxidizing capacity of the browning waste liquid; R2 is the total reducing capacity of the copper-containing waste liquid. S200, hydrogen peroxide removal: Add the specified amount of ferrous sulfate evenly to the static and stable mixed raw material liquid, keep stirring to ensure that the agent is in full contact with the waste liquid, and completely decompose the residual hydrogen peroxide in the waste liquid to obtain a stable pretreated waste liquid. S300, Low-temperature concentration: The pretreated waste liquid is placed in a vacuum low-temperature environment for continuous evaporation, and the foam on the liquid surface is monitored in real time and eliminated in time, so that the waste liquid reaches the set concentration level and forms a high-concentration concentrate. S400 Crystallization and Drying: High-concentration concentrate is subjected to secondary low-temperature treatment by a combination of intermittent feeding and circulating evaporation. The drying state of the material is controlled by the endpoint prediction algorithm throughout the process. After the material reaches the drying requirements, it is discharged while hot. The discharged material gradually solidifies and hardens after natural cooling, forming copper salt crystals. S500, Product Separation and Reuse: Collect all the condensate generated during the low-temperature concentration and crystallization drying process, and reuse it after simple treatment. Seal and collect the cooled high-copper-content dried crystallized material.

2. The method for efficient low-temperature heat pump evaporation treatment of waste liquid after mixing browning solution and copper plating solution according to claim 1, characterized in that, In step S100, the browning waste liquid and the copper-plating waste liquid are mixed by low-speed constant stirring. The stirring operation lasts for no less than 30 minutes, and the stirring speed is set to 120 r / min to 180 r / min. After stirring, the settling time is 60 minutes to 90 minutes. No external acid-base regulators or redox agents are added during the mixing process. The waste liquid completes the entire spontaneous reaction process by relying on its own physicochemical properties.

3. The method for efficient low-temperature heat pump evaporation treatment of waste liquid after mixing browning solution and copper plating solution according to claim 1, characterized in that, In step S200, the added ferrous sulfate is anhydrous ferrous sulfate solid powder. The dosage is calculated based on the volume of the mixed raw material liquid, with 0.8g of anhydrous ferrous sulfate added per liter of mixed raw material liquid. The addition method is to use a screw feeder to add the ferrous sulfate at a uniform speed. The stirring speed is set to 200r / min to 250r / min, and the stirring reaction time is 40min to 60min. During the reaction, the pH value in the container is maintained between 3.5 and 4.5, and the reaction temperature is controlled between 20℃ and 30℃. Before addition, the ferrous sulfate is dried to a moisture content below 0.5%. The addition process is uniform and uninterrupted to ensure that the reagent and the waste liquid are fully and evenly mixed, and there is no local accumulation of reagent during the reaction process. The reagent dispersion meets the requirements for uniform reaction of the waste liquid system.

4. The method for efficient low-temperature heat pump evaporation treatment of waste liquid after mixing browning solution and copper plating solution according to claim 1, characterized in that, In step S300, the vacuum degree of the vacuum low-temperature environment is controlled between -0.07MPa and -0.09MPa, the evaporation temperature of the low-temperature heat pump is set to 45℃~55℃, the continuous evaporation time is 120min~180min, the liquid surface foam monitoring adopts a photoelectric monitoring probe, the foam elimination adopts a mechanical defoaming paddle with a defoaming paddle speed of 300r / min, the defoaming trigger threshold is when the liquid surface foam height exceeds 5cm, the concentration degree is set to 25% of the original pretreated waste liquid volume, and the concentrated liquid is transported through an insulated pipeline with the pipeline temperature maintained at 50℃.

5. The method for efficient low-temperature heat pump evaporation treatment of waste liquid after mixing browning solution and copper plating solution according to claim 1, characterized in that, In step S400, the secondary low-temperature treatment temperature is maintained at 40℃~50℃, the vacuum degree is controlled at -0.07MPa, the intermittent feeding amount is 15%~20% of the total mass of the high-concentration concentrate, each cycle of evaporation is 30min, and the material is discharged after reaching the drying requirement of less than 8% moisture content. The material discharge temperature is controlled at 60℃~70℃, the discharged material is placed on a stainless steel cooling tray with a thickness of 2mm, the natural cooling environment temperature is 15℃~25℃, the cooling time is 120min~150min, and the cooling process is carried out in a sealed dust-free environment, ultimately forming a dense copper salt crystal material.

6. The method for efficient low-temperature heat pump evaporation treatment of waste liquid after mixing browning solution and copper plating solution according to claim 1, characterized in that, In step S400, the mathematical expression of the endpoint prediction algorithm is: ； Among them, W end This refers to the final moisture content of the dried material. R represents the initial moisture content of the mixture formed after synergistic mixing; opt The optimal volume mixing ratio of browning waste liquid and copper leaching waste liquid; k e This is the low-temperature evaporation rate constant; The initial viscosity of the mixture at the optimal mixing ratio; T represents the real-time viscosity of the material during the crystallization and drying process; T represents the actual evaporation temperature; T ref P is the preset reference evaporation temperature; P is the actual vacuum level; P ref The reference vacuum level is set in advance; t is the cumulative evaporation time of the material in the crystallization and drying process.

7. The method for efficient low-temperature heat pump evaporation treatment of waste liquid after mixing browning solution and copper plating solution according to claim 1, characterized in that, In step S500, the condensate is collected in a sealed collection tank at atmospheric pressure. The condensate is then treated by a quartz sand filter with a filtration accuracy of 5μm to 10μm and a filtration flow rate of 1.2m³ / h to 1.5m³ / h. The treated condensate is then reused in the cleaning process of the electroplating production line, with the reuse conveying pressure controlled at 0.2MPa.

8. The method for efficient low-temperature heat pump evaporation treatment of waste liquid after mixing browning solution and copper plating solution according to claim 1, characterized in that, In step S500, the high copper content dried crystallized material is collected in a sealed stainless steel storage tank with a volume of 200L. The filling amount of a single storage tank is controlled at 150kg. After collection, the storage tank is sealed with a lid, and the sealing pressure is maintained at 0.01MPa. The collection process is completed in a closed operating room with ventilation. The ventilation rate is set to 12 times / h. After collection, the storage tank is sealed with a lid and labeled. The temperature of the storage area is controlled at 18℃~25℃ and the humidity is controlled at 45%~60%.

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