Method and device for rapidly identifying renovated ion exchange resin

Abstract

The invention discloses a method and a device for quickly identifying renovated ion exchange resin, and relates to the field of ion exchange resin testing. When at least four colors with different depths appear, deep color impurities are attached to the outer parts of particles or impurities exist in the particles, more than 10% of particles have cracks in the inner parts or the particles are non-whole-ball particles, the resin can be identified as renovated resin, otherwise, the conductivity value of the ion exchange resin effluent is tested, the time for reaching the minimum value of the conductivity is 80-90 minutes, and the renovated resin can be identified as renovated resin. The resin is identified as renovated resin when the minimum value of the conductivity is greater than 20 [mu] S / cm and the conductivity value after 40 min of water washing is more than 10% of the conductivity value after 20 min of water washing, otherwise, the resin is not renovated resin, and the method has the advantages of rapidness, accuracy, low cost, wide application range and the like, and plays an important role in acceptance inspection of new ion exchange resin.

Description

Technical Field

[0001] The invention relates to the field of ion exchange resin testing, and in particular to a method for quickly identifying refurbished ion exchange resins and a device used therefor. Background Art

[0002] Ion exchange resin is a high-molecular-weight polymer with a backbone composed of styrene, acrylic, or other polymers. Functional groups and exchangeable ions within these groups are linked through chemical reactions. Over the course of ion exchange resin use, the functional groups gradually degrade, and their physical and chemical properties deteriorate. Furthermore, ion exchange resins can be contaminated by substances such as iron, organic matter, oil, and silicon in the influent, which can adhere to the resin surface or clog its internal pores, reducing its exchange capacity. Therefore, after a period of use, ion exchange resins are often scrapped due to significant degradation of physical and chemical parameters such as exchange capacity, water content, and iron content, requiring replacement with new resin.

[0003] To reduce the production cost of new resin, some companies currently recycle used or scrapped ion exchange resins, subjecting them to cleaning, secondary treatment, and chemical regeneration, before selling them as new ion exchange resins. For refurbished ion exchange resins, which are relatively mature, their conventional physical and chemical properties, such as exchange capacity, water content, wet true density, wet apparent density, particle size, osmotic grinding ball rate, and post-grinding ball rate, meet the acceptance standards for new ion exchange resins. Therefore, conventional product acceptance methods cannot be used to identify refurbished ion exchange resins. However, in actual use, there are still significant differences between refurbished and new ion exchange resins. This is particularly true in industries with high effluent quality requirements, such as the power, electronics, and food industries. Refurbished ion exchange resins often deteriorate effluent quality, resulting in increased conductivity, high organic content, reduced equipment output, and lower operating economic indicators. This can cause serious economic losses and production safety risks for users who were unaware of the use of refurbished ion exchange resins before commissioning.

[0004] There is currently no public method for identifying refurbished ion exchange resins that have not yet been put into use. Therefore, there is an urgent need for a method for quickly identifying refurbished ion exchange resins. Summary of the Invention

[0005] In response to the problems existing in the prior art, the present invention provides a method and device for quickly identifying refurbished ion exchange resins. Before the ion exchange resin is put into use, it can quickly and accurately identify whether it is a refurbished ion exchange resin, thereby preventing inferior products that do not meet the requirements of the technical agreement from being put into use.

[0006] The present invention is achieved through the following technical solutions: A device for testing the conductivity value of ion exchange resin effluent, comprising an exchange column and a stirring rod; The bottom of the exchange column is provided with a liquid guide tube, and the top of the exchange column is provided with a liquid outlet, a first liquid inlet, and a second liquid inlet. The exchange column is used to place the ion exchange resin to be tested, and the end of the stirring rod is deeply inserted into the exchange column. The inlet of the liquid guide tube, the inlet of the first liquid inlet, and the inlet of the second liquid inlet are respectively connected to the outlet end of the peristaltic pump, and the inlet end of the peristaltic pump is connected to the desalted water tank and the regeneration solution tank through a multi-channel switching valve; The liquid guiding tube is provided with a stop valve, which is located below the inlet of the liquid guiding tube. The end of the liquid guiding tube is communicated with the inlet of the waste liquid tank.

[0007] Preferably, the outlet end of the peristaltic pump is connected to an infusion pipeline, the outlet of the infusion pipeline is divided into a first infusion pipeline and a second infusion pipeline, a first stop valve is installed on the first infusion pipeline, the outlet of the first infusion pipeline is connected to the inlet of the catheter, and the stop valve on the catheter is a second stop valve; A third stop valve is installed on the second liquid infusion pipeline, the outlet of the second liquid infusion pipeline is divided into a regeneration solution transmission pipeline and a desalted water transmission pipeline, a fourth stop valve is installed on the regeneration solution transmission pipeline, and a fifth stop valve is installed on the desalted water transmission pipeline. The outlet of the regeneration solution transmission pipeline is connected to the inlet of the first liquid inlet, and the outlet of the desalted water transmission pipeline is connected to the inlet of the second liquid inlet; The liquid outlet is externally connected to a backwash liquid transmission pipeline, and the outlet of the backwash liquid transmission pipeline is lower than the second stop valve and is connected to the liquid guide pipe.

[0008] A method for rapidly identifying refurbished ion exchange resins comprises observing a particle layer formed by accumulation of ion exchange resin particles to be identified. When two or all of the following three conditions occur, the resin is identified as refurbished resin. First, there are at least four different shades of color; second, there are dark impurities attached to the outside of the particles, or there are impurities inside the particles; third, more than 10% of the particles have cracks inside or are not spherical particles; When any of the above situations occurs, the following steps are also performed based on the device for testing the conductivity value of the ion exchange resin effluent described in any of the above items: S1, placing the ion exchange resin to be tested in an exchange column, introducing deionized water from the deionized water tank into the exchange column through a liquid guide tube using a peristaltic pump, and continuously backwashing the ion exchange resin to be tested. The backwash liquid flows out from the liquid outlet until the ion exchange resin is fully expanded and there are no visible impurities in the backwash liquid. Then, backwashing is stopped, and the stop valve is opened to lower the liquid level in the exchange column. At the same time, the ion exchange resin is freely settled. When the liquid level is higher than the resin layer, the stop valve is closed, and the resin layer is stirred with a stirring rod to remove bubbles. S2, open the stop valve, and continuously introduce the regeneration solution in the regeneration solution tank into the exchange column from the first liquid inlet through the peristaltic pump, so that the regeneration solution passes through the ion exchange resin from top to bottom at a uniform speed, and the liquid level is kept above the resin layer. Then the effluent flows into the waste liquid tank through the liquid guide tube; S3, the deionized water in the deionized water tank is continuously introduced into the exchange column from the second liquid inlet by a peristaltic pump to wash the ion exchange resin. The effluent then flows into the waste liquid tank through the liquid guide tube. After 20 minutes, the effluent is collected every 5 minutes. When the volume reaches 15 mL, the conductivity is measured. The recording time is at least 120 minutes. The washing time is used as the horizontal axis and the measured conductivity value is used as the vertical axis to draw a graph, which is the washing curve; When the time to reach the minimum conductivity is greater than 80 minutes, the minimum conductivity is greater than 20 μS / cm, and the ratio of the conductivity after 40 minutes of water washing to that after 20 minutes of water washing is greater than 1 / 5, it is identified as refurbished resin; otherwise, it is not refurbished resin.

[0009] Preferably, in S1, the development rate of the ion exchange resin to be tested is 50% to 100%.

[0010] Preferably, in S1, the stop valve is closed when the liquid level is (20-40) mm higher than the resin layer. Preferably, in S2, (400-500) mL of the regeneration solution is passed through the ion exchange resin at a uniform speed from top to bottom within (60-90) min, and the liquid level is kept (20-40) mm above the resin layer. Preferably, for cation exchange resin, the regeneration solution is (0.8-1.2) mol / L hydrochloric acid or sulfuric acid solution, and for anion exchange resin, the regeneration solution is (1.8-2.2) mol / L sodium hydroxide solution. Preferably, in S3, the deionized water is used to wash the ion exchange resin at a flow rate of (7-10) mL / min. Preferably, the number of ion exchange resin particles in the granular layer is 500-1000 particles. 1 mL of deionized water is added to evenly spread the ion exchange resin particles on a glass slide and observed using a microscope.

[0011] Preferably, the microscope is equipped with a 10x eyepiece. Before observation, the view size and background light are adjusted so that the number of ion exchange resin particles within the visual range is (90-110).

[0012] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention provides a device for testing the electrical conductivity of ion exchange resin effluent. When observing a particle layer formed by accumulation of ion exchange resin particles to be identified, if any of the following three situations occurs, the electrical conductivity of the ion exchange resin effluent needs to be tested: first, there are at least four different shades of color; second, dark impurities are attached to the outside of the particles, or there are impurities inside the particles; third, more than 10% of the particles have cracks inside or are non-spherical particles. Therefore, it is necessary to design a device for testing the electrical conductivity of the ion exchange resin effluent, and then the conductivity value can be tested. The ion exchange resin to be tested can be placed in the exchange column, and the deionized water in the deionized water tank can be introduced into the exchange column through the liquid guide tube by a peristaltic pump, and the ion exchange resin is continuously backwashed from bottom to top. The backwash liquid can flow out from the liquid outlet, and then the stop valve is opened to lower the liquid level in the exchange column, and the ion exchange resin is freely settled. When the liquid level is higher than the resin layer, the stop valve is closed, and a stirring rod can be used to stir to remove bubbles in the resin layer; then the stop valve is opened, and the regeneration solution in the regeneration solution tank can be continuously introduced into the exchange column from the first liquid inlet by a peristaltic pump, so that the regeneration solution passes through the ion exchange resin from top to bottom at a uniform speed, and the liquid level is kept higher than the resin layer, and then the effluent flows into the waste liquid tank through the liquid guide tube; the deionized water in the deionized water tank can be continuously introduced into the exchange column from the second liquid inlet by the peristaltic pump to wash the ion exchange resin, and then the effluent flows into the waste liquid tank through the liquid guide tube, so that the conductivity value of the effluent can be tested at the required time point.

[0013] The present invention provides a method for quickly identifying refurbished ion exchange resins. By observing a particle layer formed by the accumulation of a large number of refurbished ion exchange resin particles, it can be found that the refurbished ion exchange resins have the following essential characteristics: first, poor uniformity in the secondary synthesis process; second, contaminants that have not been completely cleaned out on the outside or inside; third, poor mechanical strength and a low balling rate; and fourth, a large number of small molecules and ions in the interior due to the synthesis process, and unstable functional groups that are easily degraded and dissolved during water washing. Therefore, if it is necessary to quickly identify whether it is a refurbished ion exchange resin, the physical appearance of the ion exchange resin sample particles can be physically observed first, and whether there are any abnormalities in terms of color, impurities, and balling rate. When at least four different shades of color, dark impurities attached to the outside of the particles, impurities inside the particles, more than 10% of the particles have cracks inside, or the particles are non-ball particles, or two or all of the following are present, the refurbished resin can be identified. If only one of the following is present, it is necessary to combine the water washing characteristic test to comprehensively judge whether the ion exchange resin is a refurbished resin. The water washing characteristic test is to first backwash the ion exchange resin sample from bottom to top to fully expand it, and there is no visible impurity in the backwash solution. After the ion exchange resin is freely settled, it is ensured that there are no bubbles in the resin layer. Then, a regeneration solution is passed through the ion exchange resin at a uniform speed from top to bottom to regenerate it. Finally, it is washed with water. After 20 minutes, the conductivity of the effluent is measured every 5 minutes. The relationship between the conductivity and the water washing time is obtained and a curve is plotted to observe whether there is a clear inflection point where the conductivity decreases. The conductivity of the effluent at 120 minutes of water washing is recorded. If it takes more than 80 minutes to reach the minimum value of the conductivity, the minimum value of the conductivity is greater than 20 μS / cm, and the ratio of the conductivity after 40 minutes of water washing to that after 20 minutes of water washing is greater than 1 / 5, it is identified as refurbished resin. Otherwise, it is not refurbished resin. The method of the present invention has the advantages of being fast, accurate, low cost, and having a wide range of applications, and plays an important role in the acceptance of new ion exchange resins. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a water washing curve diagram in the sixth step of the method for identifying refurbished ion exchange resins described in Example 2 of the present invention.

[0015] Figure 2 This is a water washing curve diagram in the sixth step of the method for identifying refurbished ion exchange resins according to the present invention.

[0016] Figure 3 Schematic diagram of the device for testing the conductivity value of ion exchange resin effluent according to the present invention.

[0017] In the figure: 1-exchange column; 2-sealing plug; 3-stirring rod; 4-liquid guide; 5-waste liquid tank; 6-deionized water tank; 7-regeneration solution tank; 8-multi-channel switching valve; 9-peristaltic pump; 10-infusion pipeline; 11-liquid guide tube; 12-liquid outlet; 13-first liquid inlet; 14-second liquid inlet; 21-first infusion pipeline; 22-second infusion pipeline; 23-regeneration solution transmission pipeline; 24-deionized water transmission pipeline; 25-backwash liquid transmission pipeline; 31-first stop valve; 32-second stop valve; 33-third stop valve; 34-fourth stop valve; 35-fourth stop valve; 36-sixth stop valve; 37-seventh stop valve. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and drawings, which are intended to explain rather than limit the present invention.

[0019] The present invention provides a method for quickly identifying refurbished ion exchange resins, comprising the following steps: The first step is to take 5 mL (usually 500-1000 particles) of ion exchange resin sample, add 1 mL of deionized water and spread it evenly on a glass slide. Observe the resin particles using a microscope equipped with a 10x eyepiece. Adjust the view size and background light so that 90-110 resin particles are within the visual range. Observe the color and morphology of the resin particles. Be careful not to observe new ion exchange resins that have been stored improperly or for an extended period of time, or that have been contaminated. Step 2: If there are any of the following three abnormalities in the observation results, record them: (1) The color of the particles varies, with at least four different shades of color; (2) There are dark impurities attached to the outside of the particles, or there are impurities inside the particles; (3) More than 10% of the particles have cracks inside or are not spherical particles; If the ion exchange resin sample shows two or more abnormal conditions in the second step, it can be identified as refurbished resin; When one of the above situations occurs, further judgment is required based on the test results of the ion exchange resin effluent conductivity value. The specific process is as follows: The third step is to take (50-60) mL of ion exchange resin sample and place it in an exchange column. The exchange column can be a plexiglass exchange column or a glass sand core chromatography column of appropriate size. Deionized water is introduced into the exchange column and continuously backwashed with deionized water (to achieve bottom-up washing) until the sample development rate reaches 50%-100%. At the same time, it is necessary to ensure that there are no visible impurities in the sample, so that there are no visible impurities in the backwash liquid. Water is drained to lower the liquid level in the exchange column, and the ion exchange resin sample is freely settled. The water is drained until the liquid level is (20-40) mm higher than the resin layer, and the resin layer is stirred with a stirring rod to ensure that there are no bubbles in the resin layer. Step 4: Pass (400-500) mL of regeneration solution through the ion exchange resin sample at a constant speed from top to bottom over (60-90) minutes. For cation exchange resin, the regeneration solution is (0.8-1.2) mol / L hydrochloric acid or sulfuric acid solution. For anion exchange resin, the regeneration solution is (1.8-2.2) mol / L sodium hydroxide solution. Keep the liquid level (20-40) mm above the resin layer throughout the process. In the fifth step, deionized water is continuously introduced into the exchange column and passed through the ion exchange resin sample from top to bottom at a flow rate of (7~10) mL / min. After 20 minutes, the effluent is collected every 5 minutes. When the volume reaches 15 mL, the conductivity is measured. The washing time is used as the horizontal axis and the measured conductivity value is used as the vertical axis to draw a graph as the washing curve, and the conductivity value of the effluent at 120 minutes of washing is recorded.

[0020] Step 6: Analyze the results of step 5. The analysis method is as follows: Example 2 is the most regular water washing curve obtained by the above experiment through a large number of refurbished ion exchange resins. Example 1 is the water washing curve of the new resin. If the water washing curve in the fifth step is close to Figure 2 Example 2, where the conductivity drop after washing is not obvious (the time required to reach the minimum conductivity is greater than 80 minutes, the ratio of the conductivity after 40 minutes of washing to that after 20 minutes of washing is greater than 1 / 5, and the conductivity of the effluent after 120 minutes of washing is still greater than 20 μS / cm), is identified as refurbished resin; otherwise, it is not refurbished resin.

[0021] In order to facilitate the above process, a device for testing the conductivity of the ion exchange resin effluent can be designed. Figure 3 As shown, it includes an exchange column 1, a peristaltic pump 9 and a stirring rod 3.

[0022] A liquid guide tube 11 is provided at the bottom of the exchange column 1, a sealing plug 2 is inserted into the top of the exchange column 1, a liquid outlet 12 and a second liquid inlet 14 are respectively provided on the sealing plug 2, the first liquid inlet 13 is provided on the exchange column 1 near the sealing plug 2, the exchange column 1 can be used to place ion exchange resin, the end of the stirring rod 3 is inserted into the exchange column 1 through the sealing plug 2, the inlet of the liquid guide tube 11, the inlet of the first liquid inlet 13 and the inlet of the second liquid inlet 14 are respectively connected to the outlet end of the peristaltic pump 9, the inlet end of the peristaltic pump 9 is connected to the outlet end of the multi-channel switching valve 8, and the inlet end of the multi-channel switching valve is connected to the desalted water tank 6 and the regeneration solution tank 7 through two independent pipelines. The liquid guiding tube 11 is provided with a stop valve, which is located below the inlet of the liquid guiding tube 11 to avoid interfering with the normal liquid inflow of the liquid guiding tube 11. The end of the liquid guiding tube 11 is connected to the inlet of the waste liquid tank 5 to receive waste liquid.

[0023] Specifically, the outlet end of the peristaltic pump 9 is connected to the infusion pipeline 10, and the outlet of the infusion pipeline 10 is divided into a first infusion pipeline 21 and a second infusion pipeline 22. A first stop valve 31 is installed on the first infusion pipeline 21, and the outlet of the first infusion pipeline 21 is connected to the inlet of the catheter 11. The stop valve on the catheter 11 is specifically a second stop valve 32. A third stop valve 33 is installed on the second infusion pipeline 22, and the outlet of the second infusion pipeline 22 is divided into a regeneration solution transmission pipeline 23 and a desalted water transmission pipeline 24. A fourth stop valve 34 is installed on the regeneration solution transmission pipeline 23, and a fifth stop valve 35 is installed on the desalted water transmission pipeline 24. The outlet of the regeneration solution transmission pipeline 23 is connected to the inlet of the first liquid inlet 13, and the outlet of the desalted water transmission pipeline 24 is connected to the inlet of the second liquid inlet 14.

[0024] The liquid outlet 12 is externally connected to a backwash liquid transmission pipe 25. The outlet of the backwash liquid transmission pipe 25 is lower than the second shut-off valve 32 and is connected to the liquid guide pipe 11. A sixth shut-off valve 36 is installed near the second shut-off valve 32 of the backwash liquid transmission pipe 25. The end of the liquid guide pipe 11 is externally connected to a liquid guide 4. The outlet of the liquid guide 4 is connected to the inlet of the waste liquid tank 5. A seventh shut-off valve 37 is installed at the outlet of the liquid guide 4 near the waste liquid tank 5 to open the liquid guide 4 when necessary to receive waste liquid and replace and clean the liquid guide 4. Therefore, steps 3 to 35 are specifically carried out as follows: The third step is to take (50-60) mL of ion exchange resin sample and place it in the exchange column 1. The first stop valve 31, the sixth stop valve 36 and the seventh stop valve 37 are opened, and the second stop valve 32 and the third stop valve 33 are closed. The deionized water in the deionized water tank 6 is introduced into the exchange column 1 from the liquid guide tube 11 by the peristaltic pump 9. The deionized water is continuously backwashed (to achieve bottom-up washing). The backwash liquid flows from the liquid outlet 12 through the backwash liquid transmission pipe 25 into the waste liquid tank 5 until the sample development rate reaches 50%-100%. At the same time, it is necessary to make sure that there are no impurities visible to the naked eye in the sample. In this way, there are no impurities visible to the naked eye in the backwash liquid. The effluent is clear. Close the first stop valve 31 to stop backwashing. Open the second stop valve 32 to drain water to lower the liquid level in the exchange column 1. The ion exchange resin sample is freely settled and drained until the liquid level is (20-40) higher than the resin layer. mm Close the second stop valve 32 to stop, stir with the stirring rod 3 to ensure that there are no bubbles in the resin layer, close the seventh stop valve 37, pour out the backwash liquid in the waste liquid tank 5 and clean; The fourth step is to close the first stop valve 31, the fifth stop valve 35, and the sixth stop valve 36, and open the second stop valve 32, the third stop valve 33, the fourth stop valve 34, and the seventh stop valve 37. Through the peristaltic pump 9, within (60-90) min, the (400-500) mL regeneration solution in the regeneration solution tank 7 is uniformly passed from the first liquid inlet 13 from top to bottom through the ion exchange resin sample, and the effluent flows into the waste liquid tank 5 through the liquid guide tube 11. During the whole process, the liquid level is kept higher than the resin layer by (20-40) mm. Finally, the seventh stop valve 37 is closed, and the effluent in the waste liquid tank 5 is poured out and cleaned; The fifth step is to close the first stop valve 31, the fourth stop valve 34, and the sixth stop valve 36, and open the second stop valve 32, the third stop valve 33, the fifth stop valve 35, and the seventh stop valve 37. Through the peristaltic pump 9, the deionized water in the deionized water tank 6 is continuously introduced into the exchange column 1 from the second liquid inlet 14, and passes through the ion exchange resin sample from top to bottom. Then, the effluent flows into the waste liquid tank 5 through the liquid guide tube 11, and the flow rate is (7~10) mL / min. After 20 minutes, the effluent is collected every 5 minutes. When the volume reaches 15 mL, the conductivity is measured. The washing time is used as the horizontal axis and the measured conductivity value is used as the vertical axis to draw a graph as the washing curve, and the conductivity value of the effluent at 120 minutes of washing is recorded.

[0025] Example 1 The present invention provides a method for quickly identifying refurbished ion exchange resins, comprising the following steps: The first step is to take a 5 mL sample of newly purchased 201×7 anion exchange resin and add 1 mL of deionized water and evenly spread it on a glass slide. Observe the resin particles using a microscope equipped with a 10x eyepiece. Adjust the view size and background light so that there are 90 to 110 resin particles within the visual range. Observe the color and morphology of the resin particles. In the second step, after observation, the following two abnormalities were found in the ion exchange resin samples: first, the color of the particles varied, with at least four different shades of color; second, there were obvious dark impurities attached to the outside of the particles, and there were obvious impurities inside the particles, with uneven color; In the third step, the anion exchange resin sample of model 201×7 can be identified as refurbished resin.

[0026] Example 2 The present invention provides a method for quickly identifying refurbished ion exchange resins, comprising the following steps: The first step is to take 5 mL of a newly purchased D001 cation exchange resin sample and add 1 mL of deionized water and spread it evenly on a glass slide to form a particle layer. Observe the resin particles using a microscope equipped with a 10x eyepiece. Adjust the view size and background light so that there are 90 to 110 resin particles within the visual range. Observe the color and morphology of the resin particles. In the second step, after observation, it was found that more than 10% of the particles of the ion exchange resin sample had cracks inside or were non-spherical particles, so the next step was required; The third step is to take 50 mL of ion exchange resin sample and place it in a plexiglass exchange column. The first stop valve 31, the sixth stop valve 36 and the seventh stop valve 37 are opened, and the second stop valve 32 and the third stop valve 33 are closed. The deionized water in the deionized water tank 6 is introduced into the exchange column 1 from the liquid guide tube 11 by the peristaltic pump 9. The deionized water is continuously backwashed. The backwash liquid flows into the waste liquid tank 5 from the liquid outlet 12 through the backwash liquid transmission pipe 25 until the sample development rate is 50% to 100%. At the same time, it is necessary to make the sample free of visible impurities. The effluent is clarified and the first stop valve 31 is closed to stop backwashing. The second stop valve 32 is opened to drain water to lower the liquid level in the exchange column 1. The ion exchange resin sample is freely settled. The water is drained until the liquid level is 20 mm higher than the resin layer. The second stop valve 32 is closed to stop. The resin layer is stirred by the stirring rod 3 to ensure that there are no bubbles in the resin layer. The seventh stop valve 37 is closed, and the backwash liquid in the waste liquid tank 5 is poured out and cleaned. Step 4: Close the first stop valve 31, the fifth stop valve 35, and the sixth stop valve 36, open the second stop valve 32, the third stop valve 33, the fourth stop valve 34, and the seventh stop valve 37, and use the peristaltic pump 9 to pass the 1.0 mol / L hydrochloric acid solution in the regeneration solution tank 7 from the first liquid inlet 13 from top to bottom through the ion exchange resin sample at a uniform speed within 60 minutes. The effluent flows into the waste liquid tank 5 through the liquid guide tube 11. The amount of hydrochloric acid solution consumed is 400 mL. The liquid level is kept 22 mm above the resin layer during the entire process. Finally, close the seventh stop valve 37, pour out the effluent in the waste liquid tank 5 and clean it; Step 5: Close the first stop valve 31, the fourth stop valve 34, and the sixth stop valve 36, and open the second stop valve 32, the third stop valve 33, the fifth stop valve 35, and the seventh stop valve 37. Through the peristaltic pump 9, the deionized water in the deionized water tank 6 is continuously introduced into the exchange column 1 from the second liquid inlet 14, and passes through the ion exchange resin sample from top to bottom. After that, the effluent flows into the waste liquid tank 5 through the liquid guide tube 11 at a flow rate of 7 mL / min. After 20 minutes, the effluent is collected every 5 minutes. When the volume reaches 15 mL, the conductivity is measured. The washing time is used as the horizontal axis and the measured conductivity value is used as the vertical axis to draw a graph, as shown in FIG. Figure 1 As shown, the conductivity of the effluent after 120 min of water washing was measured to be 38.2 μS / cm; Step 6: According to the microscope observation in step 2, the ion exchange resin has an abnormal high breakage rate, and in the water washing test in step 5, the water washing curve is closer to Figure 2 In Example 2, the minimum conductivity value was reached in 90 minutes. The conductivity value after 40 minutes of water washing was 39% of the conductivity value after 20 minutes of water washing. Moreover, the conductivity value of the effluent after 120 minutes of water washing was still greater than 20 μS / cm. In summary, the D001 cation exchange resin sample was identified as a refurbished resin.

Claims

1. A device for testing the conductivity of ion exchange resin effluent, characterized in that: It includes an exchange column (1) and a stirring rod (3); The bottom of the exchange column (1) is provided with a liquid guide tube (11), the top of the exchange column (1) is provided with a liquid outlet (12), a first liquid inlet (13) and a second liquid inlet (14), the exchange column (1) is used to place the ion exchange resin to be tested, the end of the stirring rod (3) is deeply inserted into the exchange column (1), the inlet of the liquid guide tube (11), the inlet of the first liquid inlet (13) and the inlet of the second liquid inlet (14) are respectively connected to the outlet end of the peristaltic pump (9), and the inlet end of the peristaltic pump (9) is connected to the desalted water tank (6) and the regeneration solution tank (7) through the multi-channel switching valve (8); The liquid guiding tube (11) is provided with a stop valve, which is located below the inlet of the liquid guiding tube (11). The end of the liquid guiding tube (11) is connected to the inlet of the waste liquid tank (5).

2. The device for testing the conductivity of ion exchange resin effluent according to claim 1, characterized in that: The outlet end of the peristaltic pump (9) is connected to a liquid infusion pipeline (10), the outlet of the liquid infusion pipeline (10) is divided into a first liquid infusion pipeline (21) and a second liquid infusion pipeline (22), a first stop valve (31) is installed on the first liquid infusion pipeline (21), the outlet of the first liquid infusion pipeline (21) is connected to the inlet of the liquid guide tube (11), and the stop valve on the liquid guide tube (11) is a second stop valve (32); A third stop valve (33) is installed on the second liquid delivery pipeline (22), the outlet of the second liquid delivery pipeline (22) is divided into a regeneration solution transmission pipeline (23) and a desalted water transmission pipeline (24), a fourth stop valve (34) is installed on the regeneration solution transmission pipeline (23), and a fifth stop valve (35) is installed on the desalted water transmission pipeline (24), the outlet of the regeneration solution transmission pipeline (23) is connected to the inlet of the first liquid inlet (13), and the outlet of the desalted water transmission pipeline (24) is connected to the inlet of the second liquid inlet (14); The liquid outlet (12) is externally connected to a backwash liquid transmission pipeline (25), and the outlet of the backwash liquid transmission pipeline (25) is lower than the second stop valve (32) and is in communication with the liquid guide pipe (11).

3. A method for rapidly identifying refurbished ion exchange resins, characterized in that: Observe the particle layer formed by the accumulation of ion exchange resin particles to be identified. If two or all of the following three conditions occur, it is identified as refurbished resin; First, there are at least four different shades of color; second, there are dark impurities attached to the outside of the particles, or there are impurities inside the particles; third, more than 10% of the particles have cracks inside or are not spherical particles; When one of the above situations occurs, the device for testing the conductivity of the effluent of an ion exchange resin according to any one of claims 1 to 2 is used to perform the following steps: S1, placing the ion exchange resin to be tested in the exchange column (1), introducing the deionized water in the deionized water tank (6) into the exchange column (1) through the peristaltic pump (9), and continuously backwashing the ion exchange resin to be tested, and the backwash liquid flows out from the liquid outlet (12) until the ion exchange resin is fully expanded and there are no impurities visible to the naked eye in the backwash liquid, then stop backwashing, open the stop valve, and let the liquid level in the exchange column (1) drop, while the ion exchange resin is freely settled. When the liquid level is higher than the resin layer, close the stop valve, and stir with the stirring rod (3) to make sure there are no bubbles in the resin layer; S2, open the stop valve, and continuously introduce the regeneration solution in the regeneration solution tank (7) into the exchange column (1) from the first liquid inlet (13) through the peristaltic pump (9), so that the regeneration solution passes through the ion exchange resin from top to bottom at a uniform speed, and the liquid level is kept above the resin layer, and then the effluent flows into the waste liquid tank (5) through the liquid guide tube (11); S3, the deionized water in the deionized water tank (6) is continuously introduced into the exchange column (1) from the second liquid inlet (14) through the peristaltic pump (9) to wash the ion exchange resin. The effluent then flows into the waste liquid tank (5) through the liquid guide tube (11). After 20 minutes, the effluent is collected every 5 minutes. When the volume reaches 15 mL, the conductivity is measured. The recording time is at least 120 minutes. The washing time is used as the horizontal axis and the measured conductivity value is used as the vertical axis to draw a graph, which is the washing curve; If the time taken to reach the minimum conductivity value exceeds 80 minutes, the minimum conductivity value is greater than 20 μS / cm, and the ratio of the conductivity after washing for 40 minutes to that after washing for 20 minutes is greater than 1 / 5, it is identified as refurbished resin; otherwise, it is not refurbished resin.

4. The method for rapidly identifying refurbished ion exchange resins according to claim 3, wherein: In S1, when the development rate of the ion exchange resin to be tested is 50% to 100% and there are no impurities visible to the naked eye in the backwash liquid, the backwashing is stopped.

5. The method for rapidly identifying refurbished ion exchange resins according to claim 3, wherein: In S1, close the stop valve when the liquid level is (20~40) mm higher than the resin layer.

6. The method for rapidly identifying refurbished ion exchange resins according to claim 3, wherein: In S2, (400-500) mL of regeneration solution is passed through the ion exchange resin from top to bottom at a constant speed within (60-90) min, and the liquid level is kept (20-40) mm above the resin layer.

7. The method for rapidly identifying refurbished ion exchange resins according to claim 6, characterized in that: For cation exchange resin, the regeneration solution is (0.8~1.2) mol / L hydrochloric acid or sulfuric acid solution, and for anion exchange resin, the regeneration solution is (1.8~2.2) mol / L sodium hydroxide solution.

8. The method for rapidly identifying refurbished ion exchange resins according to claim 3, wherein: In S3, the deionized water is used to wash the ion exchange resin at a flow rate of (7-10) mL / min.

9. The method for rapidly identifying refurbished ion exchange resins according to claim 3, wherein: The number of ion exchange resin particles in the granular layer is 500 to 1000. 1 mL of deionized water is added to evenly spread the ion exchange resin particles on a glass slide and observed using a microscope.

10. The method for rapidly identifying refurbished ion exchange resins according to claim 9, characterized in that: The microscope is equipped with a 10x eyepiece. Before observation, the view size and background light are adjusted so that 90 to 110 ion exchange resin particles are within the visual range.

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