Heavy metal adsorption resin as well as preparation method and application thereof

Abstract

The invention discloses heavy metal adsorption resin as well as a preparation method and application thereof. The heavy metal adsorption resin is formed by grafting the melamine derivative into the chloromethyl resin through nucleophilic substitution reaction of the melamine derivative and chloromethyl in the chloromethyl resin, and the synthesis reaction is mild and simple. The heavy metal adsorption resin prepared by the invention has excellent heavy metal ion adsorption effect and good regeneration performance, is high in repeated utilization rate and good in heavy metal removal effect, and can be widely applied to wastewater treatment in the fields of hydrometallurgy and the like.

Description

Technical Field

[0001] This invention relates to the field of heavy metal adsorption materials technology, and in particular to heavy metal adsorption resins, their preparation methods, and applications. Background Technology

[0002] With the development of science and technology, the efficiency of hydrometallurgy has been significantly improved. Compared with traditional pyrometallurgical processes, which generate waste gas and wastewater that cause significant environmental pollution, hydrometallurgy can better control pollutant emissions. For some low-grade ores, hydrometallurgy can achieve economical and effective utilization. However, hydrometallurgical processes produce wastewater containing heavy metal ions, which can cause environmental pollution if not properly treated. Traditional heavy metal ion removal technologies mainly include leaching, precipitation, electrolytic deposition, solvent extraction, and ion exchange resin adsorption. Among these, leaching uses corrosive solvents and requires harsh conditions; precipitation is suitable for treating wastewater with high concentrations and few impurities; electrolytic deposition is energy-intensive and costly; and solvent extraction requires large amounts of organic reagents. In comparison, ion exchange resin adsorption offers milder conditions, simpler operation, and does not generate additional wastewater or reagents. Post-treatment is also simple, making it more suitable for wastewater treatment in hydrometallurgy. However, current resin adsorption materials are not ideal for adsorbing and removing heavy metal ions from hydrometallurgical wastewater, and the reuse rate of treated resin adsorption materials is low, resulting in poor regeneration. Summary of the Invention

[0003] Therefore, it is necessary to provide a heavy metal adsorption resin that can efficiently adsorb and remove heavy metal ions from wastewater, while also having good regeneration performance, and can be widely used in wastewater treatment processes of hydrometallurgy.

[0004] In a first aspect, this application provides a heavy metal adsorption resin, wherein the heavy metal adsorption resin is formed by nucleophilically substituting the chloromethyl group in a melamine derivative into a chloromethyl resin; the melamine derivative includes one or more of melamine cyanurate, melamine monoamide, 2,4,6-tris(dimethylamino)triazine, 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine, and hexamethylmelamine.

[0005] In some embodiments, the chloromethyl resin is selected from chloromethyl resins with a styrene-divinylbenzene backbone; and / or, the degree of crosslinking of the chloromethyl resin is 4%-10%; and / or, the chloromethyl content in the chloromethyl resin is 10%-20%; and / or, the mass ratio of the chloromethyl resin to the melamine derivative is 1:(0.3-3); and / or, the heavy metal includes heavy metals in acidic solutions; optionally, the heavy metal includes one or more of copper, soluble copper ions, and insoluble copper complexes.

[0006] Secondly, this application also provides a method for preparing a heavy metal adsorption resin, comprising the following steps:

[0007] Chloromethyl resin was swollen in a solvent, melamine derivative was added and mixed, a catalyst was added and the temperature was raised to carry out a reflux reaction. After the reaction was completed, solid-liquid separation was performed, the solid was washed, and the heavy metal adsorption resin was prepared.

[0008] The melamine derivatives include one or more of melamine cyanurate, melamine monoamide, 2,4,6-tris(dimethylamino)triazine, 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine, and hexamethylmelamine.

[0009] In some embodiments, the catalyst includes one or more of sodium carbonate, sodium hydroxide, potassium carbonate, and potassium hydroxide.

[0010] In some embodiments, the mass ratio of the solvent to the chloromethyl resin is (3-5):1; and / or, the solvent includes one or more of N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, tetrahydrofuran, and acetone; and / or, the swelling time is 0.5h-4h.

[0011] In some embodiments, the mixing time is 0.5h-2h; and / or, the temperature is increased from room temperature to the reflux temperature of the solvent at a heating rate of 1℃ / min-3℃ / min; and / or, the reflux reaction time is 8h-16h.

[0012] In some embodiments, the washing process includes a first washing treatment and a second washing treatment;

[0013] The first washing process includes rinsing the solid at least three times with alternating rinses of a first organic solvent and water.

[0014] The second washing process includes washing the solids after the first washing process with a second organic solvent.

[0015] In some embodiments, the first organic solvent and the second organic solvent each independently comprise one or more of methanol, ethanol, isopropanol and butanol; and / or, the second washing treatment is performed by Soxhlet extraction; and / or, the second washing treatment lasts for 2-8 hours; and / or, the mass ratio of the second organic solvent to the solid after the first washing treatment is (3-6):1.

[0016] In some embodiments, the chloromethyl resin is further subjected to a cleaning process before swelling; optionally, the cleaning process is performed by Soxhlet extraction.

[0017] In some embodiments, the solvent for the cleaning process includes one or more of methanol, ethanol, isopropanol, and butanol; and / or, the cleaning process takes 2-8 hours.

[0018] Thirdly, this application also provides an application of a heavy metal adsorption resin in the metallurgical industry, wherein the heavy metal adsorption resin includes the heavy metal adsorption resin provided in the first aspect, or the heavy metal adsorption resin prepared by the preparation method provided in the second aspect.

[0019] Optionally, the wastewater includes hydrometallurgical wastewater;

[0020] Optionally, the wastewater is acidic wastewater.

[0021] Compared with traditional technologies, the beneficial effects of the technical solution in this application include:

[0022] This application provides a type of heavy metal adsorption resin, which grafts melamine derivatives into chloromethyl resin through a nucleophilic substitution reaction between melamine derivatives and chloromethyl groups in chloromethyl resin, thereby achieving excellent heavy metal ion adsorption effect and good regeneration performance. Attached Figure Description

[0023] Figure 1 The process flow diagram for preparing the heavy metal adsorption resin provided in this application is shown.

[0024] Figure 2 The infrared spectrum of the melamine derivative and the heavy metal adsorption resin prepared therefrom in Example 1 of this application is shown. Detailed Implementation

[0025] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0026] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] Ion exchange adsorption resins are widely used in industry due to their mild operating conditions and simple operation in wastewater treatment. The treatment of wastewater containing heavy metal ions using ion exchange adsorption resins is a dynamic adsorption-desorption process. Heavy metal ions are adsorbed by the ion exchange resin and then eluted with a suitable eluent, thus achieving wastewater purification.

[0029] However, traditional ion adsorption resins are not ideal for treating heavy metal wastewater from hydrometallurgical processes, and their regeneration efficiency is poor. Therefore, this application aims to provide a heavy metal adsorption resin that can adsorb heavy metal ions from hydrometallurgical wastewater, while also exhibiting excellent regeneration and good reusability.

[0030] In a first aspect, this application provides a heavy metal adsorption resin, wherein the heavy metal adsorption resin is formed by nucleophilically substituting the chloromethyl group in a melamine derivative into a chloromethyl resin; the melamine derivative includes one or more of melamine cyanurate, melamine monoamide, 2,4,6-tris(dimethylamino)triazine, 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine, and hexamethylmelamine.

[0031] This application achieves the grafting of melamine derivatives into chloromethyl resin through a nucleophilic substitution reaction between melamine derivatives and chloromethyl groups in chloromethyl resin, thereby forming a resin with excellent heavy metal adsorption performance.

[0032] In some embodiments, the melamine derivative is melamine cyanurate, which undergoes a nucleophilic substitution reaction with the chloromethyl group in the chloromethyl resin as follows:

[0033]

[0034] In some embodiments, the melamine derivative is a melamine monoamide, which undergoes a nucleophilic substitution reaction with the chloromethyl group in the chloromethyl resin as follows:

[0035]

[0036] In some embodiments, the melamine derivative is 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine, and its nucleophilic substitution reaction with the chloromethyl group in the chloromethyl resin is as follows:

[0037]

[0038] In some embodiments, the chloromethyl resin is selected from chloromethyl resins with a styrene-divinylbenzene backbone. As a non-limiting example, the chloromethyl resin is selected from LQ117 of Wandong High-Tech (Tianchang) Co., Ltd.

[0039] In some embodiments, the degree of crosslinking of the chloromethyl resin is 4%-10%, including but not limited to 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any combination thereof and values ​​within that range.

[0040] In some embodiments, the chloromethyl content in the chloromethyl resin is 10%-20%, including but not limited to 10%, 12%, 14%, 16%, 18%, 20%, or any range formed by both of the foregoing and values ​​within that range. It is understood that the chloromethyl content can be by weight.

[0041] In some embodiments, the mass ratio of the chloromethyl resin to the melamine derivative is 1:(0.3-3), including but not limited to 1:0.3, 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3 or any of the foregoing ranges and values ​​within those ranges.

[0042] In some embodiments, the heavy metal includes heavy metals in acidic solutions. Exemplarily, the heavy metal includes one or more of copper, soluble copper ions, insoluble copper complexes, nickel, soluble nickel ions, insoluble nickel complexes, lead, soluble lead ions, insoluble lead complexes, mercury, soluble mercury ions, insoluble mercury complexes, cobalt, soluble cobalt ions, and insoluble cobalt complexes. As a non-limiting example, the heavy metal includes Cu(II), Ni(II), Pb(II), Hg(II), and Co(II); further, the heavy metal includes one or more of copper, soluble copper ions, and insoluble copper complexes.

[0043] The heavy metal adsorption resin prepared in this application achieves excellent heavy metal adsorption performance, especially in low-pH waste liquids, solving the technical problem that traditional adsorption resins have unsatisfactory heavy metal adsorption performance under acidic conditions. Therefore, the heavy metals mentioned in this application include heavy metals in acidic solutions with a pH of 1-4. It is understood that the acidic solution includes acidic waste liquids from hydrometallurgical industries.

[0044] The heavy metal adsorption resin prepared in this application exhibits selectivity for heavy metal ions, specifically targeting the adsorption of particular ions, including Cu(II), Ni(II), Pb(II), Hg(II), and Co(II), with particularly high selectivity for Cu(II). Therefore, the heavy metals mentioned in this application include one or more of Cu(II), Ni(II), Pb(II), Hg(II), and Co(II); further, the heavy metals include Cu(II); even further, the biomolecular structure of the heavy metal adsorption resin prepared in this application incorporates a melamine derivative containing O and N atoms, grafted onto a chloromethyl resin, enabling O atoms to coordinate with N atoms, thereby enhancing the adsorption capacity of Cu. This further enhances its excellent Cu(II) adsorption in acidic solutions (low-pH waste liquid, meaning the pH of the acidic solution is 1-4), thus removing copper ions from the acidic solution.

[0045] In addition, the heavy metal adsorption resin prepared in this application has excellent regeneration effect. It can be regenerated by inorganic acid treatment and obtain excellent adsorption effect, and has high reusability.

[0046] Secondly, this application also provides a method for preparing a heavy metal adsorption resin, comprising the following steps:

[0047] Chloromethyl resin was swollen in a solvent, melamine derivative was added and mixed, a catalyst was added and the temperature was raised to carry out a reflux reaction. After the reaction was completed, solid-liquid separation was performed, the solid was washed, and the heavy metal adsorption resin was prepared.

[0048] The melamine derivatives include one or more of melamine cyanurate, melamine monoamide, 2,4,6-tris(dimethylamino)triazine, 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine, and hexamethylmelamine.

[0049] This application employs a reflux reaction between a swollen chloromethyl resin and a melamine derivative under catalytic conditions. The melamine derivative nucleophilically replaces the chloromethyl group in the chloromethyl resin, thereby achieving a resin with a melamine derivative structure grafted onto the chloromethyl resin and enabling the adsorption of heavy metal ions.

[0050] In some embodiments, the catalyst includes one or more of sodium carbonate, sodium hydroxide, potassium carbonate, and potassium hydroxide.

[0051] In some embodiments, the mass ratio of the solvent to the chloromethyl resin is (3-5):1, including but not limited to 3:1, 4:1, 5:1 or any of the foregoing ranges and values ​​within those ranges.

[0052] In some embodiments, the solvent includes one or more of N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, tetrahydrofuran, and acetone.

[0053] In some embodiments, the swelling time is 0.5h-4h, including but not limited to 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h or any of the foregoing ranges and values ​​within that range.

[0054] In some embodiments, the mixing time is 0.5h-2h, including but not limited to 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h, 2h or any of the foregoing ranges and values ​​within that range.

[0055] In some embodiments, the temperature is increased from room temperature to the reflux temperature of the solvent at a rate of 1°C / min to 3°C / min.

[0056] In some embodiments, the reflux reaction time is 8h-16h, including but not limited to 8h, 90h, 10h, 11h, 12h, 13h, 14h, 15h, 16h or any of the foregoing ranges and values ​​within that range.

[0057] In some embodiments, the washing process includes a first washing treatment and a second washing treatment;

[0058] The first washing process includes rinsing the solid at least three times with alternating rinses of a first organic solvent and water.

[0059] The second washing process includes washing the solids after the first washing process with a second organic solvent.

[0060] This application washes the resin by performing a first washing treatment and a second washing treatment in sequence, thereby rinsing away residual reactants in the resin structure during the synthesis process, obtaining a larger specific surface area and adsorption sites, exposing more space for adsorbing heavy metal ions, and especially improving the adsorption effect on copper ions in acidic solutions.

[0061] In some embodiments, during the washing process, the first organic solvent and the second organic solvent each independently include one or more of methanol, ethanol, isopropanol and butanol.

[0062] In some embodiments, the second washing process is performed using Soxhlet extraction.

[0063] In some embodiments, the second washing process takes 2-8 hours, including but not limited to 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, or any combination thereof and values ​​within that range.

[0064] In some embodiments, the mass ratio of the second organic solvent to the first washed solid is (3-6):1, including but not limited to 3:1, 4:1, 5:1, 6:1 or any of the foregoing ranges and values ​​within those ranges.

[0065] In some embodiments, the process further includes cleaning the chloromethyl resin before swelling; see Appendix. Figure 1 As a non-limiting example, the cleaning process is performed by Soxhlet extraction.

[0066] In some embodiments, the solvent used for cleaning includes one or more of methanol, ethanol, isopropanol, and butanol.

[0067] In some embodiments, the cleaning process takes 2-8 hours, including but not limited to 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, or any combination thereof and values ​​within that range.

[0068] Thirdly, this application also provides an application of a heavy metal adsorption resin in the metallurgical industry, wherein the heavy metal adsorption resin includes the heavy metal adsorption resin provided in the first aspect, or the heavy metal adsorption resin prepared by the preparation method provided in the second aspect.

[0069] In some embodiments, the wastewater includes hydrometallurgical wastewater;

[0070] In some embodiments, the wastewater is acidic wastewater. As a non-limiting example, the pH of the acidic solution is 1-4.

[0071] It should be noted that experimental methods in the following embodiments of this application, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All commonly used chemical reagents used in the embodiments are commercially available products, or can be prepared by those skilled in the art using known methods.

[0072] The types and sources of some of the raw materials and reagents involved in the specific embodiments of this application are as follows:

[0073] Chloromethyl resin: LQ117, purchased from Wandong High-Tech (Tianchang) Co., Ltd.

[0074] Example 1

[0075] This embodiment provides a method for preparing a heavy metal adsorption resin, and the specific preparation steps are as follows:

[0076] The chloromethyl resin was washed for 4 hours in a Soxhlet extractor filled with ethanol (ethanol to chloromethyl resin mass ratio of 5:1).

[0077] The cleaned chloromethyl resin was swollen in N,N-dimethylformamide for 1 hour, then melamine cyanurate was added and stirred for 0.5 hours. Sodium carbonate was then added, and the reaction system was heated from room temperature to the solvent reflux temperature at a heating rate of 2 °C / min for 12 hours. The mass ratio of the cleaned chloromethyl resin to N,N-dimethylformamide was 1:5, and the mass ratio of the cleaned chloromethyl resin, melamine cyanurate, and sodium carbonate was 1:1:0.1.

[0078] The resin prepared after the above reaction was completed was filtered and rinsed three times alternately with ethanol and water.

[0079] The above-washed resin was washed with ethanol (ethanol to washed resin mass ratio of 5:1) for 4 hours using a Soxhlet extractor to obtain heavy metal adsorption resin.

[0080] The heavy metal adsorption resin prepared above was subjected to infrared spectroscopy determination, and the results are shown in the appendix. Figure 2 .

[0081] Example 2

[0082] This embodiment provides a method for preparing a heavy metal adsorption resin, and the specific preparation steps are as follows:

[0083] The chloromethyl resin was washed for 4 hours in a Soxhlet extractor filled with ethanol (ethanol to chloromethyl resin mass ratio of 5:1).

[0084] The cleaned chloromethyl resin was swollen in N,N-dimethylformamide for 1 hour, melamine monoamide was added and stirred for 0.5 hours, sodium carbonate was added, and the reaction system was heated from room temperature to solvent reflux temperature at a heating rate of 2℃ / min for 12 hours. The mass ratio of the cleaned chloromethyl resin to N,N-dimethylformamide was 1:5, and the mass ratio of the cleaned chloromethyl resin, melamine monoamide and sodium carbonate was 1:1:0.1.

[0085] The resin prepared after the above reaction was completed was filtered and rinsed three times alternately with ethanol and water.

[0086] The above-washed resin was washed with ethanol (ethanol to washed resin mass ratio of 5:1) for 4 hours using a Soxhlet extractor to obtain heavy metal adsorption resin.

[0087] Example 3

[0088] This embodiment provides a method for preparing a heavy metal adsorption resin, and the specific preparation steps are as follows:

[0089] The chloromethyl resin was washed for 4 hours in a Soxhlet extractor filled with ethanol (ethanol to chloromethyl resin mass ratio of 5:1).

[0090] The cleaned chloromethyl resin was swollen in N,N-dimethylformamide for 1 hour, then 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine was added and stirred for 0.5 hours. Sodium carbonate was then added, and the reaction system was heated from room temperature to the solvent reflux temperature at a rate of 2 °C / min for 12 hours. The mass ratio of the cleaned chloromethyl resin to N,N-dimethylformamide was 1:5, and the mass ratio of the cleaned chloromethyl resin, 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine to sodium carbonate was 1:1:0.1.

[0091] The resin prepared after the above reaction was completed was filtered and rinsed three times alternately with ethanol and water.

[0092] The above-washed resin was washed with ethanol (ethanol to washed resin mass ratio of 5:1) for 4 hours using a Soxhlet extractor to obtain heavy metal adsorption resin.

[0093] Examples 4-15

[0094] The difference from Example 3 is that the resin prepared after the reaction was completed was filtered and rinsed using the following washing method:

[0095] Example 4: Rinse once with ethanol.

[0096] Example 5: Rinse once with water.

[0097] Example 6: Rinse once with alternating ethanol and water.

[0098] Example 7: Rinse twice with ethanol.

[0099] Example 8: Rinse twice with water.

[0100] Example 9: Rinse twice with alternating ethanol and water.

[0101] Example 10: Rinse three times with ethanol.

[0102] Example 11: Rinse with water 3 times.

[0103] Example 12: Rinse three times with alternating ethanol and water.

[0104] Example 13: Rinse 4 times with ethanol.

[0105] Example 14: Rinse with water 4 times.

[0106] Example 15: Rinse four times with alternating ethanol and water.

[0107] The above-mentioned rinsed resins were washed with ethanol (ethanol to rinsed resin mass ratio of 5:1) for 4 hours using a Soxhlet extractor to obtain heavy metal adsorption resins.

[0108] Experimental Example 1: Test of Heavy Metal Adsorption Efficiency of Heavy Metal Adsorption Resin

[0109] The heavy metal adsorption performance of the heavy metal adsorption resins prepared in Examples 1-3 was tested. 10g of each of the heavy metal adsorption resins prepared in Examples 1-3 was used to test the heavy metal adsorption of 5 heavy metal acidic wastewater samples. The 5 heavy metal acidic wastewater samples contained different heavy metal ions Cu(II), Ni(II), Pb(II), Hg(II) and Co(II). The specific composition of the raw water samples is shown in Table 1.

[0110] The heavy metal adsorption resins prepared in Examples 1-3 were packed into glass chromatography columns to treat 20 BV of wastewater at a flow rate of 2 BV / h. The contents of Cu(II), Ni(II), Pb(II), Hg(II), Co(II), and Fe(III) in the water were determined by ICP. The results are shown in Table 1.

[0111] Table 1: Adsorption effect of the heavy metal adsorption resins prepared in Examples 1-3 on various heavy metal ions

[0112]

[0113] Note: 0 indicates not detected, due to the equipment's detection limit.

[0114] As can be clearly seen from the results in Table 1, the heavy metal adsorption resin prepared in this application exhibits excellent adsorption properties for Cu(II), Ni(II), Pb(II), Hg(II), and Co(II), and the removal rates of Cu(II), Ni(II), Pb(II), Hg(II), and Co(II) ions in raw water all exceed 90% selective adsorption, while the adsorption effect on Fe(III) is relatively weak. It is evident that the heavy metal adsorption resin prepared in this application can specifically adsorb and remove total metal ions from acidic wastewater.

[0115] Experimental Example 2: Regeneration Performance of Heavy Metal Adsorption Resin

[0116] The resin that had undergone heavy metal adsorption treatment in Example 1 was regenerated using a 20% H2SO4 solution as the regenerator. The heavy metals adsorbed in Examples 1-3 of the above-mentioned Example 1 that had undergone heavy metal adsorption treatment were desorbed and regenerated. After regeneration, the heavy metal adsorption process of Example 1 was repeated. The average regeneration rate data of the resin after three repetitions are shown in Table 2.

[0117] Table 2: Regeneration performance of heavy metal adsorption resins prepared in Examples 1-3 for various heavy metal ions

[0118]

[0119] The results in Table 2 clearly show that the heavy metal adsorption resin prepared by melamine derivatives and chloromethyl resin in this application has excellent regeneration performance and high reusability.

[0120] Experimental Example 3: Effect of Washing Method on Heavy Metal Adsorption Capacity of Heavy Metal Adsorption Resin

[0121] The heavy metal adsorption performance of the heavy metal adsorption resins prepared in Examples 4-15 on water sample 1 in Experiment 1 was tested using the same method as in Experiment 1. The results are shown in Table 3.

[0122] Table 3: Adsorption effect of heavy metal adsorption resins prepared in Examples 4-15 on Cu(II)

[0123]

[0124] As shown in Table 3, compared with rinsing with ethanol or water alone, the heavy metal adsorption resin prepared by alternating rinsing with ethanol and water in this application has better adsorption capacity. Furthermore, the heavy metal adsorption capacity of the resin increases with the number of alternating rinsings with ethanol and water; when rinsing with alternating ethanol and water three times, the Cu(II) removal rate reaches 100%. This may be because alternating rinsing with ethanol and water can more effectively clean the pores inside the resin, exposing more space for adsorbing metal ions.

[0125] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A heavy metal adsorption resin, characterized in that, The heavy metal adsorption resin is formed by nucleophilically substituting the chloromethyl group in the chloromethyl resin with a melamine derivative; the melamine derivative includes one or more of melamine cyanurate, melamine monoamide, 2,4,6-tris(dimethylamino)triazine, 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine, and hexamethylmelamine.

2. The heavy metal adsorption resin according to claim 1, characterized in that, The chloromethyl resin is selected from chloromethyl resins with a styrene-divinylbenzene backbone; and / or, the degree of crosslinking of the chloromethyl resin is 4%-10%; and / or, the chloromethyl content in the chloromethyl resin is 10%-20%; and / or, the mass ratio of the chloromethyl resin to the melamine derivative is 1:(0.3-3); and / or, the heavy metal includes heavy metals in acidic solutions; optionally, the heavy metal includes one or more of copper, soluble copper ions, and insoluble copper complexes.

3. A method for preparing heavy metal adsorption resin, characterized in that, Includes the following steps: Chloromethyl resin was swollen in a solvent, melamine derivative was added and mixed, a catalyst was added and the temperature was raised to carry out a reflux reaction. After the reaction was completed, solid-liquid separation was performed, the solid was washed, and the heavy metal adsorption resin was prepared. The melamine derivatives include one or more of melamine cyanurate, melamine monoamide, 2,4,6-tris(dimethylamino)triazine, 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine, and hexamethylmelamine.

4. The method for preparing the heavy metal adsorption resin according to claim 3, characterized in that, The catalyst comprises one or more of sodium carbonate, sodium hydroxide, potassium carbonate, and potassium hydroxide; and / or, the mass ratio of the solvent to the chloromethyl resin is (3-5):1; and / or, the solvent comprises one or more of N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, tetrahydrofuran, and acetone; and / or, the swelling time is 0.5h-4h.

5. The method for preparing the heavy metal adsorption resin according to claim 3, characterized in that, The mixing time is 0.5h-2h; and / or the temperature is increased from room temperature to the reflux temperature of the solvent at a rate of 1℃ / min-3℃ / min; and / or the reflux reaction time is 8h-16h.

6. The method for preparing the heavy metal adsorption resin according to claim 3, characterized in that, The washing process includes a first washing treatment and a second washing treatment; The first washing process includes rinsing the solid at least three times with alternating rinses of a first organic solvent and water. The second washing process includes washing the solids after the first washing process with a second organic solvent.

7. The method for preparing the heavy metal adsorption resin according to claim 6, characterized in that, The first organic solvent and the second organic solvent each independently include one or more of methanol, ethanol, isopropanol and butanol; and / or, the second washing treatment is performed by Soxhlet extraction; and / or, the second washing treatment time is 2h-8h; and / or, the mass ratio of the second organic solvent to the solid after the first washing treatment is (3-6):

1.

8. The method for preparing the heavy metal adsorption resin according to any one of claims 3 to 7, characterized in that, The process before swelling also includes cleaning the chloromethyl resin; optionally, the cleaning is performed by Soxhlet extraction.

9. The method for preparing the heavy metal adsorption resin according to claim 8, characterized in that, The solvent used for cleaning includes one or more of methanol, ethanol, isopropanol, and butanol; and / or the cleaning time is 2-8 hours.

10. The application of heavy metal adsorption resin in wastewater treatment, characterized in that, The heavy metal adsorption resin includes the heavy metal adsorption resin according to claim 1 or 2, or the heavy metal adsorption resin prepared by the preparation method according to any one of claims 3 to 9. Optionally, the wastewater includes hydrometallurgical wastewater; Optionally, the wastewater is acidic wastewater.

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