Method for detecting concentration of copper ions in copper-containing sludge

Abstract

The invention discloses a method for detecting the concentration of copper ions in copper-containing sludge, and the method comprises the following steps: carrying out primary digestion on a copper-containing sludge sample through a sulfuric acid solution and a hydrogen peroxide solution to obtain a copper solution sample; and detecting the copper solution sample through an electroplating solution analyzer to obtain a copper ion concentration reading result of the copper solution sample. Through the design, the detection efficiency of the copper ions in the copper-containing sludge can be improved, and large-scale detection can be realized.

Description

Technical Field

[0001] This application relates to the field of copper foil manufacturing technology, and in particular to a method for detecting the concentration of copper ions in copper-containing sludge. Background Technology

[0002] Electrolytic copper foil is a crucial material in the manufacture of copper-clad laminates, printed circuit boards, and lithium-ion batteries. In today's rapidly developing electronics and information industry, electrolytic copper foil is often referred to as the "neural network" for signal and power transmission and communication in electronic products. The production process of electrolytic copper foil is relatively simple, mainly including solution forming, surface treatment, and product slitting. However, the production of electrolytic copper foil generates copper-containing wastewater, and the copper, iron, and other metals and their compounds in this wastewater will eventually settle to the bottom, forming copper-containing sludge. For manufacturers, this copper-containing sludge contains a certain amount of copper, and after testing the copper ion concentration, the sludge can be treated to recover copper resources.

[0003] Currently, the main methods for detecting copper ion concentration in copper-containing sludge are iodometric titration and flame atomic absorption spectrophotometry. However, both of these methods require multiple digestions of the copper-containing sludge before detection, which makes the pretreatment complex and results in low detection efficiency of copper ion concentration in copper-containing sludge, which is not conducive to batch detection. Summary of the Invention

[0004] The purpose of this application is to provide a method for detecting the concentration of copper ions in copper-containing sludge, so as to improve the detection efficiency of copper ions in copper-containing sludge.

[0005] This application discloses a method for detecting the concentration of copper ions in copper-containing sludge, the method comprising the following steps: A copper-containing sludge sample was digested once using sulfuric acid solution and hydrogen peroxide solution to obtain a copper solution sample; and The copper solution sample was analyzed using an electroplating solution analyzer to obtain the copper ion concentration reading.

[0006] Optionally, the step of digesting the copper-containing sludge sample once with sulfuric acid solution and hydrogen peroxide solution to obtain a copper solution sample includes: Weigh out a predetermined mass of copper-containing sludge sample and place it in a container; A first preset volume of sulfuric acid solution and a second preset volume of hydrogen peroxide solution are added to the container, and after a preset reaction time, a mixed solution is obtained. The mixed solution is filtered to obtain a filtrate and a filter residue; and The filtrate was diluted to a final volume to obtain a copper solution sample.

[0007] Optionally, the preset mass is 5g, the first preset volume is 20mL, the second preset volume is 5mL, and the filtrate is diluted to a 100mL volumetric flask to obtain the copper solution sample.

[0008] Optionally, in the step of filtering the mixed solution to obtain filtrate and filter residue, the mixed solution is filtered through a filter membrane with a pore size of 0.45µm.

[0009] Optionally, in the step of digesting the copper-containing sludge sample with sulfuric acid solution and hydrogen peroxide solution to obtain a copper solution sample, after digesting the copper-containing sludge sample with sulfuric acid solution and hydrogen peroxide solution, the pH value of the digested solution is adjusted to 3.4-4.2 to obtain the copper solution sample.

[0010] Optionally, before the step of detecting the copper solution sample using an electroplating solution analyzer and obtaining the copper ion concentration reading of the copper solution sample, a calibration curve is set in the electroplating solution analyzer. The linear equation of the calibration curve is Y=0.0874X+0.0117, where Y represents the response intensity of the electroplating solution analyzer to the copper solution sample, and X represents the copper ion concentration of the copper solution sample.

[0011] Optionally, the accuracy and precision of the copper ion concentration readings can be analyzed, specifically including the following steps: The copper solution samples were divided into a low-concentration sample group, a medium-concentration sample group, and a high-concentration sample group, and each of the low-concentration sample group, the medium-concentration sample group, and the high-concentration sample group contained multiple test solution samples. Each sample in the low-concentration sample group is spiked with a low concentration, each sample in the medium-concentration sample group is spiked with a medium concentration, and each sample in the high-concentration sample group is spiked with a high concentration. The concentration of each test solution sample in the low concentration sample group, the concentration of each test solution sample in the medium concentration sample group, and the concentration of each test solution sample in the high concentration sample group were detected respectively. Calculate the average and standard deviation of the concentrations of multiple test solutions in the low-concentration sample group, the average and standard deviation of the concentrations of multiple test solutions in the medium-concentration sample group, and the average and standard deviation of the concentrations of multiple test solutions in the high-concentration sample group; Calculate the spiked recoveries of the low-concentration sample group, the medium-concentration sample group, and the high-concentration sample group. If the spiked recoveries of the low-concentration sample group, the medium-concentration sample group, and the high-concentration sample group are all within a preset standard range, then the copper ion concentration reading is determined to meet the accuracy requirements; and Calculate the relative standard deviation of the low-concentration sample group, the relative standard deviation of the medium-concentration sample group, and the relative standard deviation of the high-concentration sample group. If the relative standard deviations of the low-concentration sample group, the medium-concentration sample group, and the high-concentration sample group are all within the preset deviation range, then it is determined that the copper ion concentration reading result meets the precision requirements.

[0012] Optionally, the preset recovery rate range is 80% to 110%, and the preset deviation range is 0.4% to 0.9%.

[0013] Optionally, the method for detecting the copper ion concentration in copper-containing sludge further includes the following steps: Multiple copper-containing sludge samples were obtained from the same batch of copper-containing sludge; Obtain the copper ion concentration readings from the multiple copper solution samples; Calculate the average, standard deviation, and relative standard deviation of multiple copper ion concentration readings; and If the standard deviation and relative standard deviation of multiple copper ion concentration readings meet the preset conditions, then the copper-containing sludge sample is judged to meet the sampling requirements.

[0014] Optionally, the preset conditions are: the standard deviation of the multiple copper ion concentration readings does not exceed 0.15%, and the relative standard deviation of the multiple copper ion concentration readings does not exceed 1.4%.

[0015] The beneficial effects of this application embodiment are as follows: Compared with the method of detecting the copper ion concentration in copper-containing sludge by iodometric titration or flame atomic absorption spectrophotometry, which requires multiple digestions of the copper-containing sludge before the copper ion concentration can be detected, this application embodiment only requires one digestion of the copper-containing sludge sample using sulfuric acid solution and hydrogen peroxide solution to detect the copper ion concentration in the copper-containing sludge. Therefore, this application embodiment simplifies the pretreatment process of copper-containing sludge, improves the detection efficiency of copper ion concentration in copper-containing sludge, and is beneficial for batch detection. Attached Figure Description

[0016] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings: Figure 1This is a flowchart of a method for detecting the concentration of copper ions in copper-containing sludge provided in an embodiment of this application; Figure 2 Based on Figure 1 Detailed schematic diagram; Figure 3 This is a flowchart of another method for detecting copper ion concentration in copper-containing sludge provided in an embodiment of this application; Figure 4 This is a flowchart of another method for detecting the concentration of copper ions in copper-containing sludge provided in an embodiment of this application. Detailed Implementation

[0017] It should be understood that the terminology, specific structural and functional details used herein are merely for describing particular embodiments and are representative. However, this application may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0018] Furthermore, unless otherwise explicitly specified and limited, "connected" or "linked" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0019] There are currently two main methods for detecting the concentration of copper ions in copper-containing sludge. The first is the iodometric method used in the industry standard "Method for Determination of Copper Content in Copper-Containing Sludge", and the second is the flame atomic absorption spectrophotometry.

[0020] When using the iodometric method for detection, the copper-containing sludge needs to be first digested by heating with sulfuric acid and nitric acid, followed by a second digestion with nitric acid and perchloric acid. After digestion, the Cu is reduced with potassium iodide under slightly acidic conditions. 2+ The copper content was calculated by titrating the precipitated iodine with sodium thiosulfate.

[0021] When using flame atomic absorption spectrophotometry for detection, the copper-containing sludge needs to be first heated and digested with hydrochloric acid and nitric acid, followed by a second heating and digestion with nitric acid. After digestion, the solution is diluted to a fixed volume and then detected using an atomic absorption spectrophotometer to obtain the copper content.

[0022] However, when using the iodometric method to detect copper ion concentration in copper-containing sludge, the sludge needs to be digested multiple times, making the pre-testing process complex. Furthermore, the titration process requires precise pH control, is time-consuming, and is susceptible to interference, making it unsuitable for analyzing large quantities of samples. Similarly, when using flame atomic absorption spectrophotometry to detect copper ion concentration in copper-containing sludge, the high cost of the equipment and the need for multiple digestions and rigorous filtration of the sludge make the process complex and unsuitable for analyzing large quantities of samples.

[0023] To address the aforementioned issues, this application provides a method for detecting copper ion concentration in copper-containing sludge, thereby improving the detection efficiency and adapting to the detection of large batches of samples.

[0024] like Figure 1 As shown, the method for detecting the copper ion concentration in the copper-containing sludge includes the following steps: S1; The copper-containing sludge sample was digested once with sulfuric acid solution and hydrogen peroxide solution to obtain a copper solution sample; S2; The copper solution sample is tested using an electroplating solution analyzer to obtain the copper ion concentration reading of the copper solution sample.

[0025] Copper-containing sludge is mainly adsorbed onto the sludge in the form of copper sulfate. In this embodiment, sulfuric acid and hydrogen peroxide are added to extract the copper from the sludge and convert it into detectable Cu. 2+ Then, qualitative and quantitative analysis was performed using an electroplating solution analyzer.

[0026] Compared to methods like iodometric titration or flame atomic absorption spectrophotometry, which require multiple digestions of the copper-containing sludge to detect copper ion concentration, this embodiment only requires a single digestion of the copper-containing sludge sample using sulfuric acid and hydrogen peroxide solutions. Furthermore, it eliminates the need for high-temperature and strictly controlled pH environments. Therefore, this embodiment simplifies the pretreatment process for copper-containing sludge, improves the efficiency of copper ion concentration detection, and facilitates batch testing.

[0027] This application embodiment treats copper-containing sludge samples with sulfuric acid solution, dissolving metal oxides or hydroxides to form sulfates. Simultaneously, hydrogen peroxide is added as an oxidant to promote copper dissolution. Furthermore, during the addition of hydrogen peroxide solution, the hydrogen peroxide oxidizes copper metal particles in the copper-containing sludge sample into copper ions. Meanwhile, precious metals such as Ag and Au, due to their high standard electrode potential, are typically not oxidized and are insoluble in sulfuric acid solution, thus accumulating in the sludge. Therefore, this application embodiment detects the content of copper in all existing forms in copper-containing sludge, improving the accuracy of copper ion concentration detection in copper-containing sludge.

[0028] In some embodiments, the copper-containing sludge samples are dried and ground before digestion to improve the digestion efficiency of sulfuric acid solution and hydrogen peroxide solution on the copper-containing sludge samples.

[0029] like Figure 2 As shown, step S1 also includes: S11: Weigh a predetermined mass of copper-containing sludge sample and place it in a container; S12: Add a first preset volume of sulfuric acid solution and a second preset volume of hydrogen peroxide solution to the container, and after reacting for a preset time, obtain a mixed solution; S13: Filter the mixed solution to obtain filtrate and filter residue; S14: Adjust the volume of the filtrate to obtain a copper solution sample.

[0030] In some embodiments, the preset mass is 5g, the first preset volume is 20mL, the second preset volume is 5mL, and the filtrate is diluted to a 100mL volumetric flask to obtain the copper solution sample.

[0031] As a specific illustration, 5g of copper-containing sludge sample (accurate value 0.0001g) was weighed and added to 20mL of a 1:1 dilute sulfuric acid solution and 5mL of hydrogen peroxide solution for digestion. Digestion was considered complete when the reaction solution stopped bubbling, yielding a mixed solution. The mixed solution was then filtered to obtain filtrate and filter residue. The filter residue was washed with water, and the filtrate was diluted to a 100mL volumetric flask, shaken well, and placed in an electroplating solution analyzer for copper ion concentration testing.

[0032] It should be noted that the first preset volume can be greater than 20 mL, and the second preset volume can be greater than 5 mL to achieve an over-reaction, which does not affect the detection results of copper ions. Furthermore, the quality of the copper-containing sludge sample can be selected from other options. Additionally, the preset time is based on the point at which the digestion solution stops bubbling. Since different amounts of copper-containing sludge sample, different amounts of sulfuric acid solution, different amounts of hydrogen peroxide solution, and external environmental factors will all affect the reaction time, the specific time should be determined based on the actual situation and is not limited here.

[0033] In some embodiments, the mixed solution is filtered through a 0.45µm pore size membrane to remove insoluble micro-solid particles, preventing these particles from affecting detection and ensuring the normal operation of the electroplating solution analyzer. Furthermore, using a 0.45µm membrane not only reduces costs but also improves filtration efficiency. Of course, in other embodiments, other types of membranes or filters can be used to filter the mixed solution.

[0034] In some embodiments, in step S1, after digesting the copper-containing sludge sample once with sulfuric acid solution and hydrogen peroxide solution, the pH value of the digested solution is adjusted to 3.4-4.2 to obtain a copper solution sample. Since the digested solution contains not only a large amount of copper ions but also iron ions, adjusting the pH value of the digested solution to 3.4-4.2 allows iron ions to precipitate while copper ions remain in the solution, avoiding interference from iron ions in the copper solution sample with the detection results during copper ion detection.

[0035] In step S2, the electroplating solution analyzer is a DPX6600 model, specifically including a cuvette for holding the plating solution to be tested, a light source and photoelectric conversion unit located on both sides of the cuvette, an MCU unit connected to the photoelectric conversion unit, and an analysis result output display unit connected to the MCU unit. The electroplating solution analyzer used in this embodiment is based on optical principles. It selects a suitable light source to irradiate the copper ions in the copper solution sample, analyzes the concentration of copper ions in the copper solution sample based on the degree of light absorption by the copper solution sample, and displays the analysis results.

[0036] The analysis results output unit displays the machine-readable concentration C and mass fraction W of the copper solution sample to be tested, expressed as a percentage (%). The formula for calculation is as follows: .

[0037] Where c is the machine-readable concentration of the copper solution sample (i.e., the copper ion concentration), v is the fixed volume of the copper solution sample, f is the dilution factor of the filtrate, m is the mass of the copper-containing sludge sample, Wstandard is the mass fraction of the copper sulfate pentahydrate standard, and 103 is the conversion factor.

[0038] In some embodiments, after step S1, this application further performs digestion testing on the copper solution sample to determine whether a single digestion can completely digest the copper-containing sludge sample. Specifically, in addition to testing the copper solution sample obtained from the first digestion, the filter residue obtained after filtering the mixed solution produced in the first digestion is washed and filtered again. The washing liquid is then placed in an electroplating solution analyzer for testing. Finally, the filter residue is subjected to a second digestion using 20 mL of a 1:1 dilute sulfuric acid and 5 mL of hydrogen peroxide solution. After the solution stops bubbling, it is filtered through a 0.45 μm filter membrane, washed with water, and then diluted to a 100 mL volumetric flask. The solution is shaken well and placed in an electroplating solution analyzer for testing.

[0039] The copper content (copper ion concentration) detected in the first digestion, the washing liquid after the first digestion, and the second digestion are shown in Table 1. As can be seen from Table 1, the copper content measured in the washing liquid after the first digestion and the second digestion is 0.035% and 0.096%, respectively, which are negligible compared with the total copper content in the first digestion. Therefore, the digestion method in this embodiment can digest copper-containing sludge relatively completely, and only one digestion is required. The operation procedure is simple and can be adopted.

[0040]

[0041] Table 1: Schematic diagram of pretreatment test results for copper solution samples In some embodiments, prior to step S2, a calibration curve is set in the electroplating solution analyzer, the linear equation of which is Y = 0.0874X + 0.0117, where Y represents the response intensity of the electroplating solution analyzer to the copper solution sample, and X represents the copper ion concentration of the copper solution sample.

[0042] It should be noted that the blank conditions must be kept consistent when establishing the calibration curve to avoid experimental errors.

[0043] Specifically, as shown in Table 2, 0, 0.7843 g, 1.5686 g, 2.3529 g, and 3.1373 g of copper sulfate pentahydrate were weighed into 100 mL beakers, and 10 mL of sulfuric acid was added. Then, the volume was diluted to 100 mL with water and shaken well to prepare copper standard solutions with concentrations of 0, 2, 4, 6, and 8 g / L. These five copper standard solutions were then placed into an electroplating solution analyzer for reading. The electroplating solution analyzer showed different response intensities for copper standard solutions of different concentrations.

[0044]

[0045] Table 2: Calibration Curve Plotting Parameters After testing and verification, the linear correlation coefficient R of the calibration curve is 0.9999. The calibration curve meets the requirements for linearity and calibration in "Requirements for Validation and Internal Quality Control of Chemical Analysis Methods" (GB / T 32465-2015), and also meets the method requirements.

[0046] In some embodiments, the method detection limit and quantitation limit tests are also performed. Specifically, referring to the methods specified in Appendix A.1 Method Detection Limit and A.2 Quantitation Limit in the "Technical Guidelines for the Development of Environmental Monitoring and Analysis Methods Standards" (HJ 168-2020), the target analyte is not detected in the blank test. The blank is spiked and n (n≥7) parallel determinations are performed. The standard deviation of the n parallel determinations is calculated, and the method detection limit is calculated according to formula (A.1): MDL = ,in The value is 3.143, where S is the standard deviation.

[0047] As shown in Table 3, the detection limit and quantification limit of the blank sample were tested according to the full sample analysis procedure. The experimental verification showed that the detection limit of copper was 0.02 g / L and the quantification limit was 0.06 g / L.

[0048]

[0049] Table 3: Schematic diagram of method detection limit and lower limit of quantitation test results In some embodiments, such as Figure 3 As shown, after step S2, the accuracy and precision of the copper ion concentration readings are further analyzed, specifically including the following steps: S3: The copper solution sample is divided into a low concentration sample group, a medium concentration sample group, and a high concentration sample group, and each of the low concentration sample group, the medium concentration sample group, and the high concentration sample group contains multiple test solution samples; S4: Spike each sample in the low-concentration sample group at a low concentration, spike each sample in the medium-concentration sample group at a medium concentration, and spike each sample in the high-concentration sample group at a high concentration. S5: Detect the concentration of each test solution sample in the low concentration sample group, the concentration of each test solution sample in the medium concentration sample group, and the concentration of each test solution sample in the high concentration sample group, respectively. S6: Calculate the average and standard deviation of the concentrations of multiple test solutions in the low-concentration sample group, the average and standard deviation of the concentrations of multiple test solutions in the medium-concentration sample group, and the average and standard deviation of the concentrations of multiple test solutions in the high-concentration sample group. S7: Calculate the spiked recovery rate of the low-concentration sample group, the spiked recovery rate of the medium-concentration sample group, and the spiked recovery rate of the high-concentration sample group. If the spiked recovery rates of the low-concentration sample group, the medium-concentration sample group, and the high-concentration sample group are all within the preset recovery rate range, then it is determined that the copper ion concentration reading result meets the accuracy requirements. S8: Calculate the relative standard deviation of the low-concentration sample group, the relative standard deviation of the medium-concentration sample group, and the relative standard deviation of the high-concentration sample group. If the relative standard deviations of the low-concentration sample group, the medium-concentration sample group, and the high-concentration sample group are all within the preset deviation range, then determine that the copper ion concentration reading result meets the precision requirements.

[0050] Specifically, as shown in Table 4, 18 test samples were extracted from the copper solution samples, with 6 test samples each from the low-concentration, medium-concentration, and high-concentration sample groups. Then, the copper-containing sludge solution was spiked with 40 g / L copper standard solution at low, medium, and high concentrations, respectively. The analysis was performed in parallel six times according to the complete sample analysis procedure, and the spike recovery rate and relative standard deviation were calculated.

[0051]

[0052] Table 4: Schematic diagram of spiked recovery test results (unit: g) The results showed that the recovery rate of the copper solution samples ranged from 93.7% to 98.7%, falling within the preset recovery range of 80% to 110%, thus meeting the accuracy requirements of the method. The standard deviations for low, medium, and high concentration spikes of the copper solution samples were 0.004 g, 0.004 g, and 0.008 g, respectively, with relative standard deviations of 0.65%, 0.48%, and 0.86%, all within the preset deviation range of 0.4% to 0.9%. Therefore, the precision met the quality control and related quality management requirements of this method.

[0053] In some embodiments, the present application also analyzes actual samples. For example... Figure 4 As shown, the method for detecting the copper ion concentration in copper-containing sludge further includes the following steps: S01: Obtain multiple copper-containing sludge samples from the same batch of copper-containing sludge; S02: Obtain the copper ion concentration readings from the multiple copper solution samples; S03: Calculate the average, standard deviation, and relative standard deviation of the multiple copper ion concentration readings; S04: If the standard deviation and relative standard deviation of multiple copper ion concentration readings meet the preset conditions, then the copper-containing sludge sample is judged to meet the sampling requirements.

[0054] Specifically, in this embodiment of the application, six copper-containing sludge samples were collected from the same batch of copper-containing sludge, and the copper ion concentration in the copper-containing sludge was detected using the above-mentioned detection method. Furthermore, the calibration curve design described above was adopted, and the accuracy and precision analysis of the copper ion concentration reading results were performed as described above.

[0055] As shown in Table 5, the standard deviation of the copper solution samples obtained from these copper-containing sludge samples was 0.10%, not exceeding 0.15%; the relative standard deviation of the copper solution samples obtained from these copper-containing sludge samples was 1.31%, not exceeding 1.4%. Therefore, it meets the accuracy and precision requirements of the method and related quality control and management requirements. It can be seen that the copper-containing sludge samples in this application embodiment meet the conditions, and the copper ion concentration reading results obtained in this application embodiment are also the overall results of the copper-containing sludge, thereby avoiding the problem of abnormal copper ion concentration reading results caused by excessively high or low local copper content in the copper-containing sludge.

[0056]

[0057] Table 5: Schematic diagram of spiked recovery test results (unit: %) The method for detecting copper ion concentration in copper-containing sludge provided in this application has a simple and efficient pretreatment digestion process for copper-containing sludge samples, which does not require multiple digestions. Furthermore, the digested copper solution sample can be directly analyzed, and the reading is sufficient without dilution. In addition, the method for detecting copper ion concentration in copper-containing sludge provided in this application also has the advantages of low detection limit, high accuracy, stable readings, simple operation, and short processing time, making it suitable for batch detection.

[0058] It should be noted that the limitations of each step involved in this solution are not considered as limiting the order of steps, provided that they do not affect the implementation of the specific solution. The steps listed first can be executed first, later, or even simultaneously. Solutions from different embodiments can be combined and applied without conflict. As long as this solution can be implemented, they should be considered to fall within the protection scope of this application.

[0059] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. A method for detecting the concentration of copper ions in copper-containing sludge, characterized in that, Including the following steps: A copper solution sample was obtained by digesting the copper-containing sludge sample in one step using sulfuric acid solution and hydrogen peroxide solution. as well as The copper solution sample was analyzed using an electroplating solution analyzer to obtain the copper ion concentration reading.

2. The method for detecting copper ion concentration in copper-containing sludge as described in claim 1, characterized in that, The step of digesting copper-containing sludge samples with sulfuric acid solution and hydrogen peroxide solution to obtain copper solution samples includes: Weigh out a predetermined mass of copper-containing sludge sample and place it in a container; A first preset volume of sulfuric acid solution and a second preset volume of hydrogen peroxide solution are added to the container, and after a preset reaction time, a mixed solution is obtained. The mixed solution is filtered to obtain a filtrate and a filter residue; and The filtrate was diluted to a final volume to obtain a copper solution sample.

3. The method for detecting copper ion concentration in copper-containing sludge as described in claim 2, characterized in that, The preset mass is 5g, the first preset volume is 20mL, the second preset volume is 5mL, and the filtrate is diluted to a 100mL volumetric flask to obtain the copper solution sample.

4. The method for detecting copper ion concentration in copper-containing sludge as described in claim 2, characterized in that, In the step of filtering the mixed solution to obtain filtrate and filter residue, the mixed solution is filtered through a filter membrane with a pore size of 0.45µm.

5. The method for detecting copper ion concentration in copper-containing sludge as described in claim 1, characterized in that, In the step of digesting copper-containing sludge samples with sulfuric acid solution and hydrogen peroxide solution to obtain copper solution samples, after digesting the copper-containing sludge samples with sulfuric acid solution and hydrogen peroxide solution, the pH value of the digested solution is adjusted to 3.4-4.2 to obtain copper solution samples.

6. The method for detecting copper ion concentration in copper-containing sludge as described in claim 1, characterized in that, Before the step of detecting the copper solution sample using an electroplating solution analyzer and obtaining the copper ion concentration reading of the copper solution sample, a calibration curve is set in the electroplating solution analyzer. The linear equation of the calibration curve is Y=0.0874X+0.0117, where Y represents the response intensity of the electroplating solution analyzer to the copper solution sample, and X represents the copper ion concentration of the copper solution sample.

7. The method for detecting copper ion concentration in copper-containing sludge as described in claim 1, characterized in that, The accuracy and precision of the copper ion concentration readings are analyzed, specifically including the following steps: The copper solution samples were divided into a low-concentration sample group, a medium-concentration sample group, and a high-concentration sample group, and each of the low-concentration sample group, the medium-concentration sample group, and the high-concentration sample group contained multiple test solution samples. Each sample in the low-concentration sample group is spiked with a low concentration, each sample in the medium-concentration sample group is spiked with a medium concentration, and each sample in the high-concentration sample group is spiked with a high concentration. The concentration of each test solution sample in the low concentration sample group, the concentration of each test solution sample in the medium concentration sample group, and the concentration of each test solution sample in the high concentration sample group were detected respectively. Calculate the average and standard deviation of the concentrations of multiple test solutions in the low-concentration sample group, the average and standard deviation of the concentrations of multiple test solutions in the medium-concentration sample group, and the average and standard deviation of the concentrations of multiple test solutions in the high-concentration sample group; Calculate the spiked recovery rates of the low-concentration sample group, the medium-concentration sample group, and the high-concentration sample group. If the spiked recovery rates of the low-concentration sample group, the medium-concentration sample group, and the high-concentration sample group are all within the preset recovery rate range, then the copper ion concentration reading result is determined to meet the accuracy requirements. as well as Calculate the relative standard deviation of the low-concentration sample group, the relative standard deviation of the medium-concentration sample group, and the relative standard deviation of the high-concentration sample group. If the relative standard deviations of the low-concentration sample group, the medium-concentration sample group, and the high-concentration sample group are all within the preset deviation range, then it is determined that the copper ion concentration reading result meets the precision requirements.

8. The method for detecting copper ion concentration in copper-containing sludge as described in claim 7, characterized in that, The preset recovery rate range is 80% to 110%, and the preset deviation range is 0.4% to 0.9%.

9. The method for detecting copper ion concentration in copper-containing sludge as described in claim 1, characterized in that, The method for detecting the copper ion concentration in copper-containing sludge also includes the following steps: Multiple copper-containing sludge samples were obtained from the same batch of copper-containing sludge; Obtain the copper ion concentration readings from the multiple copper solution samples; Calculate the average, standard deviation, and relative standard deviation of the multiple copper ion concentration readings; as well as If the standard deviation and relative standard deviation of multiple copper ion concentration readings meet the preset conditions, then the copper-containing sludge sample is judged to meet the sampling requirements.

10. The method for detecting copper ion concentration in copper-containing sludge as described in claim 9, characterized in that, The preset conditions are: the standard deviation of multiple copper ion concentration readings does not exceed 0.15%, and the relative standard deviation of multiple copper ion concentration readings does not exceed 1.4%.

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