Styrene anion resin for hydrometallurgy and preparation method thereof

Abstract

The invention relates to the technical field of anion exchange, in particular to styrene anion resin for hydrometallurgy and a preparation method of the styrene anion resin. The preparation method of the anion resin comprises the following steps: polymerizing divinylbenzene serving as a cross-linking agent with styrene, then carrying out polymerization reaction with a pore-foaming agent, an initiator, a dispersing agent and the like to obtain styrene white balls, carrying out chlorination and amination, and then reacting with isocyanate pyridine for functionalization to obtain the styrene anion resin with functional groups. The adsorption capacity and the thermal stability of the anion resin on heavy metal ions are improved. Compared with the prior art, the anion resin prepared by the invention has strong adsorption capacity on heavy metal ions and good thermal stability.

Description

Technical Field

[0001] The invention relates to the technical field of anion exchange, in particular to a styrene-based anion resin for hydrometallurgy and a preparation method thereof. Background Art

[0002] Styrene anion resin is a high molecular functional material based on styrene-divinylbenzene copolymer, with quaternary ammonium group as functional group, which can perform ion exchange in acidic, neutral or alkaline environment. The appearance of this resin is milky white to light yellow spherical particles, with high exchange capacity and good physical and chemical stability. They are widely used in water treatment, hydrometallurgy, biochemical product extraction and wastewater treatment.

[0003] Styrene anion resins can be used in a pH range of 1 to 14. These resins have good selective adsorption capacity for metal ions, so they are often used in hydrometallurgy to extract metals such as tungsten and molybdenum. In addition, they are also used in the preparation of pure water and high-purity water, as well as to remove unwanted ions from solutions to improve the purity of metals. In wastewater treatment, these resins can effectively remove anionic pollutants such as nitrates, phosphates, chlorides, and ammonium ions from water, which contributes to environmental protection and resource recycling. Styrene anion resins also have good heat resistance and corrosion resistance, as well as high physical and mechanical strength, making them very reliable in industrial applications.

[0004] CN102463155A relates to a method for preparing a macroporous weakly basic anion exchange resin, which comprises the following steps in sequence: step 1, using a mixed alcohol of butanol and dodecanol with a molar ratio of 1:0.3 as a porogen, benzoyl peroxide as an initiator, gelatin and a small amount of ammonium salt as a dispersant, crosslinking and copolymerizing styrene and divinylbenzene to obtain a styrene-divinylbenzene copolymer; the porogen is 1-1.2 times the sum of the volumes of styrene and divinylbenzene, and the molar ratio of divinylbenzene to styrene is 4-8:100; step 2, under the catalytic action of zinc chloride, chloromethylating the white ball with chloromethyl ether to obtain a chloromethylated copolymer; step 3, ammonating the chlorine ball with a dimethylamine solution to obtain a macroporous weakly basic anion exchange resin. The invention increases the mesopore ratio of the white ball, increases the adsorption speed of the ion exchange resin, and ensures that the white ball has a certain number of small pores, thereby ensuring the exchange capacity of the ion exchange resin.

[0005] CN104788599A discloses a method for preparing a macroporous weakly basic anion exchange resin, which belongs to the technical field of polymer materials; it includes the following steps: using divinylbenzene as a crosslinking agent, polymerizing with styrene, selecting isopentane as a porogen, benzoyl peroxide as an initiator, gelatin as a dispersant, methylene blue as an indicator, and deionized water as a polymerization carrier, synthesizing a resin skeleton white ball through suspension polymerization; introducing chloromethyl groups on the benzene ring of the white ball through a chloromethylation reaction to obtain a chlorine ball; the chlorine ball is then reacted with α-aminopyridine to introduce functional groups on the chlorine ball, thereby obtaining a macroporous weakly basic anion exchange resin. The resin product obtained by the invention has high selectivity, high exchange capacity, easy desorption and regeneration, unique performance, and can be applied to the treatment process of rare and precious metal ions such as platinum, palladium, and rhenium. The invention has a high synthesis yield and an environmentally friendly process.

[0006] At present, anion exchange resins are widely used in water treatment, power industry, separation and purification of biological and chemical drugs, and catalytic synthesis. However, due to poor thermal stability, its use temperature usually does not exceed 60°C. This limitation is due to the fact that the quaternary amine groups in the resin are directly connected to the carbon atoms, resulting in an increase in the positive charge of the carbon atoms, which reduces the thermal stability and limits its application range. In addition, for high-concentration heavy metal wastewater, the treatment effect of ion exchange resins may be poor due to insufficient adsorption performance, so these have become urgent problems that need to be solved. Summary of the invention

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a styrene-based anion resin for hydrometallurgy and a preparation method thereof.

[0008] Styrene anion resin has an ion exchange function, can adsorb and enrich metal ions from dilute solutions, and has different ion exchange selectivity for mixed metal ions. This selectivity allows the resin to effectively separate and enrich specific metal ions. Styrene anion resin has good acid and alkali resistance, which enables it to work stably in acidic or alkaline media during hydrometallurgical processes without being damaged. However, there are still problems of insufficient adsorption performance for high-concentration heavy metal wastewater and poor heat resistance. Therefore, the present invention provides a styrene anion resin, and the prepared styrene white ball is chlorinated and aminated, and then reacted with isocyanate pyridine for functionalization, thereby obtaining a styrene anion resin with functional groups. When the groups contained in isocyanate pyridine are different, the performance of the resin is also different. Since isocyanate pyridine undergoes nucleophilic addition with amino groups, the obtained styrene anion resin has amide and pyridine groups, and the nitrogen atoms and oxygen atoms on the amide can react with metal ions to form chelates. The pyridine group can also form chelates with heavy metal ions. This chelation further enhances the selectivity and adsorption capacity for heavy metal ions. Due to the strong hydrogen bonding ability between amide molecules and the high polarity of amide molecules, and pyridine as an aromatic heterocycle, the introduction of the two also improves the heat resistance of the resin.

[0009] To achieve the above object, the present invention provides a method for preparing a styrene-based anion resin for hydrometallurgy, comprising the following steps:

[0010] S1. Mix styrene, porogen and divinylbenzene, add initiator, stir at 20-30°C for 0.5-1h, mix evenly, and obtain oil phase;

[0011] S2, add gelatin, boric acid and sodium hydroxide to water, raise the temperature to 75-80°C, add sodium lignin sulfonate, continue to raise the temperature to 80-85°C, add sodium chloride, mix well to obtain an aqueous phase;

[0012] S3, mixing the oil phase and the water phase evenly, stirring at 80-82°C until the gel point appears, and then keeping the temperature and stirring for 4-6 hours, then heating to 85-90°C, keeping the temperature and stirring for 1-3 hours to polymerize, filtering after the reaction, washing, drying, and sieving the obtained styrene white balls for the next step;

[0013] S4, mix anhydrous ferric chloride and chloromethyl ether, stir until dissolved, add styrene white balls, add chlorosulfonic acid at 20-30°C, heat to 40-45°C, keep stirring for 8-12h, then cool to 20-30°C, filter, wash and dry the obtained chlorine balls for the next step; the main function of chlorosulfonic acid is to remove the very small amount of water contained in the raw material chloromethyl ether or styrene white balls, and it can also be used as a catalyst;

[0014] S5. After swelling the chlorine ball, wash it with water, mix it with sodium hydroxide and tetrabutylammonium bromide in water, then perform amination, filter and wash it, then mix it with isocyanate pyridine in a solvent, wash it after reaction, and dry it to obtain a styrene anion resin for hydrometallurgy.

[0015] Furthermore, the porogen is isobutanol.

[0016] Furthermore, the initiator is benzoyl peroxide.

[0017] Furthermore, the mass ratio of styrene, porogen, divinylbenzene and initiator is 7-8:1:1-2:0.01-0.02.

[0018] Furthermore, the mass ratio of the gelatin, boric acid and sodium hydroxide, sodium lignin sulfonate, sodium chloride and water is 0.2-0.4:0.2-0.3:0.1-0.2:0.05-0.1:2.5-3:100.

[0019] Furthermore, the mass ratio of the anhydrous ferric chloride to chloromethyl ether, styrene white balls and chlorosulfonic acid is 0.01-0.015:1-1.5:1:0.005-0.01.

[0020] Furthermore, the specific operation of step S5 includes the following steps: adding the chlorine ball to 8 to 12 times the weight of dioxane to swell, then washing with water, adding to water, then adding sodium hydroxide and tetrabutylammonium bromide, heating to 80 to 85°C and adding ethylenediamine, amination for 8 to 14 hours and filtering, after washing, adding to 20 to 30 times the weight of the chlorine ball in dichloromethane, mixing with isocyanate pyridine, reacting at 20 to 30°C for 14 to 24 hours, filtering, washing and drying to obtain a styrene anion resin for hydrometallurgy.

[0021] Furthermore, the mass ratio of the chlorine ball to sodium hydroxide, tetrabutylammonium bromide, ethylenediamine and isocyanate pyridine is 1:1-3:0.01-0.1:15-35:0.8-3.

[0022] Preferably, the isocyanate pyridine is one of 5-isocyanate-2-methylpyridine, 4-(5-isocyanate pentyloxy)-2,6-bis(2-pyridyl)pyridine or 5-isocyanate-2-(2-pyridyl)pyridine.

[0023] The invention also provides a styrene anion resin for hydrometallurgy, which is prepared by the above method.

[0024] Beneficial effects of the present invention:

[0025] The invention provides a styrene-based anion resin. Prepared styrene white balls are subjected to chlorination and amination, and then reacted with isocyanate pyridine for functionalization, thereby obtaining a styrene-based anion resin with functional groups, thereby improving the adsorption capacity and thermal stability of the anion resin for heavy metal ions. DETAILED DESCRIPTION

[0026] 5-Isocyano-2-methylpyridine, CAS: 732245-99-7.

[0027] 4-(5-isocyanatopentoxy)-2,6-bis(2-pyridinyl)pyridine, CAS: 773157-44-1. Commercially available from Chemhere or self-made from di-tert-butyl tricarbonate and 5-(2,6-bipyridin-2-ylpyridin-4-yl)oxypentane-1-amine. The structural formula is as follows:

[0028]

[0029] 5-isocyanato-2-(2-pyridinyl)pyridine, CAS: 1383979-56-3. Commercially available from Chemhere, the structural formula is as follows:

[0030]

[0031] Example 1

[0032] A method for preparing a styrene-based anionic resin for hydrometallurgy comprises the following steps:

[0033] S1. Mix 3.96 kg of styrene, 515.4 g of isopropanol and 699.84 g of divinylbenzene, add 53.86 g of benzoyl peroxide, stir at 25°C for 0.5 h, mix well, and obtain an oil phase;

[0034] S2, add 62.19g of gelatin, 50.54g of boric acid and 33.56g of sodium hydroxide to 19.96kg of water, heat to 80°C, add 15.10g of sodium lignin sulfonate, continue to heat to 85°C, add 553.81g of sodium chloride, mix well to obtain an aqueous phase;

[0035] S3, the oil phase and the water phase are mixed evenly, stirred at 81°C until the gel point appears, and then the temperature is kept warm and stirred for 5 hours, and then the temperature is raised to 88°C, and the temperature is kept warm and stirred for 2 hours to polymerize. After the reaction is completed, the obtained styrene white balls are washed, dried, and sieved for the next step;

[0036] S4, 15g of anhydrous ferric chloride and 1.65kg of chloromethyl ether were mixed, stirred until dissolved, 1.25kg of styrene white balls were added, 11.48g of chlorosulfonic acid was added at 25°C, the temperature was raised to 42°C, the mixture was stirred for 10h, the temperature was lowered to 25°C, filtered, and the obtained chlorine balls were washed and dried for the next step;

[0037] S5. Add 1 kg of chlorine balls to 10 kg of dioxane and swell for 10 hours, then wash with water, add to 15 kg of water, add 1.5 kg of sodium hydroxide and 50 g of tetrabutylammonium bromide, heat to 82°C and add 21.5 kg of ethylenediamine, filter after amination for 14 hours, wash and add to 25 kg of dichloromethane, mix with 0.8 kg of 5-isocyano-2-methylpyridine, react at 25°C for 18 hours, filter, wash and dry to obtain styrene anion resin for hydrometallurgy.

[0038] Example 2

[0039] The process is substantially the same as Example 1, except that 0.8 kg of 5-isocyanato-2-methylpyridine is replaced by 1.18 kg of 5-isocyanato-2-(2-pyridyl)pyridine.

[0040] Example 3

[0041] The process is substantially the same as Example 1, except that 0.8 kg of 5-isocyanato-2-methylpyridine is replaced by 2.15 kg of 4-(5-isocyanatopentyloxy)-2,6-bis(2-pyridyl)pyridine.

[0042] Comparative Example 1

[0043] A method for preparing a styrene-based anionic resin for hydrometallurgy comprises the following steps:

[0044] S1. Mix 3.96 kg of styrene, 515.4 g of isopropanol and 699.84 g of divinylbenzene, add 53.86 g of benzoyl peroxide, stir at 25°C for 0.5 h, mix well, and obtain an oil phase;

[0045] S2, add 62.19g of gelatin, 50.54g of boric acid and 33.56g of sodium hydroxide to 19.96kg of water, heat to 80°C, add sodium lignin sulfonate, continue to heat to 85°C, add sodium chloride, mix well to obtain an aqueous phase;

[0046] S3, the oil phase and the water phase are mixed evenly, stirred at 81°C until the gel point appears, and then the temperature is kept warm and stirred for 5 hours, and then the temperature is raised to 88°C, and the temperature is kept warm and stirred for 2 hours to polymerize. After the reaction is completed, the obtained styrene white balls are washed, dried, and sieved for the next step;

[0047] S4, 15g of anhydrous ferric chloride and 1.65kg of chloromethyl ether were mixed, stirred until dissolved, 1.25kg of styrene white balls were added, 11.48g of chlorosulfonic acid was added at 25°C, the temperature was raised to 42°C, the mixture was stirred for 10h, the temperature was lowered to 25°C, filtered, and the obtained chlorine balls were washed and dried for the next step;

[0048] S5. Add 1 kg of chlorine balls into 10 kg of dioxane to swell for 10 hours, then wash with water, add into 15 kg of water, add 1.5 kg of sodium hydroxide and 50 g of tetrabutylammonium bromide, heat to 82°C and add 21.5 kg of ethylenediamine, aminize for 14 hours, filter, wash and dry to obtain styrene anion resin for hydrometallurgy.

[0049] Comparative Example 2

[0050] A method for preparing a styrene-based anionic resin for hydrometallurgy comprises the following steps:

[0051] S1. Mix 3.96 kg of styrene, 515.4 g of isopropanol and 699.84 g of divinylbenzene, add 53.86 g of benzoyl peroxide, stir at 25°C for 0.5 h, mix well, and obtain an oil phase;

[0052] S2, add 62.19g of gelatin, 50.54g of boric acid and 33.56g of sodium hydroxide to 19.96kg of water, heat to 80°C, add sodium lignin sulfonate, continue to heat to 85°C, add sodium chloride, mix well to obtain an aqueous phase;

[0053] S3, the oil phase and the water phase are mixed evenly, stirred at 81°C until the gel point appears, and then the temperature is kept warm and stirred for 5 hours, and then the temperature is raised to 88°C, and the temperature is kept warm and stirred for 2 hours to polymerize. After the reaction is completed, the obtained styrene white balls are washed, dried, and sieved for the next step;

[0054] S4, 15g of anhydrous ferric chloride and 1.65kg of chloromethyl ether were mixed, stirred until dissolved, 1.25kg of styrene white balls were added, 11.48g of chlorosulfonic acid was added at 25°C, the temperature was raised to 42°C, the mixture was stirred for 10h, the temperature was lowered to 25°C, filtered, and the obtained chlorine balls were washed and dried for the next step;

[0055] S5. Add 1 kg of chlorine balls to 10 kg of dioxane to swell for 10 hours, then wash with water, add to 15 kg of water, add 1.5 kg of sodium hydroxide and 50 g of tetrabutylammonium bromide, heat to 82°C and add 21.5 kg of ethylenediamine, filter after amination for 14 hours, wash and add to 25 kg of dichloromethane, mix with 0.8 kg of p-toluene isocyanate, react at 25°C for 18 hours, filter, wash and dry to obtain styrene anion resin for hydrometallurgy.

[0056] Test Example 1

[0057] The adsorption performance of the styrene-based anion resin prepared in the embodiment and the control example was tested. The adsorption tests of palladium, platinum and rhenium were respectively carried out. The mass concentration of metal ions in the solution before and after adsorption was measured to calculate the adsorption rate. The specific results are shown in Table 1.

[0058] Table 1 Heavy metal adsorption test results of styrene-based macroporous strong base anionic resin

[0059] Experimental protocol Palladium adsorption rate / % Platinum adsorption rate / % Rhenium adsorption rate / % Example 1 97.6 96.7 96.9 Example 2 98.2 97.9 97.5 Example 3 99.3 99.2 99.1 Comparative Example 1 88.9 89.2 89.9 Comparative Example 2 91.5 91.1 92.3

[0060] Styrene anion resins contain basic groups that can dissociate into OH groups in water. - The positively charged groups of this resin can adsorb and bind to metal ions in the solution, thereby producing anion exchange. - Exchange with metal ions in the solution to achieve adsorption of metal ions.

[0061] As can be seen from Table 1, the styrene anion resin prepared by the present invention has a good adsorption effect on heavy metal ions, and the embodiment has a significantly better adsorption effect than the reference examples 1 and 2. This may be due to the functionalization of the aminated styrene white balls in the embodiment, thereby obtaining a styrene anion resin with a functional group. Since the isocyanate pyridine undergoes nucleophilic addition with the amino group, the obtained styrene anion resin has amide and pyridine groups, and the nitrogen and oxygen atoms on the amide can react with the metal ions to form a chelate. The pyridine group can also form a chelate with the heavy metal ions. This chelation further enhances the selectivity and adsorption capacity of heavy metal ions, so the adsorption rate for palladium, platinum and rhenium is higher. In reference example 1, the aminated chlorine balls are not functionalized, and the p-toluene isocyanate used in reference example 2 does not have a pyridine group, so the adsorption rate is not as good as in the embodiment. Compared with Examples 2 to 3, Example 1 has the highest adsorption rate in Example 3. This is because the 5-isocyanato-2-methylpyridine in Example 1 has only one pyridine heterocycle, while the 5-isocyanato-2-(2-pyridyl)pyridine in Example 2 has two pyridine heterocycles, and the 4-(5-isocyanatepentyloxy)-2,6-bis(2-pyridyl)pyridine in Example 3 has three pyridine heterocycles and an ether bond, so it has a stronger adsorption capacity for metals. The anion resin in Example 3 has the highest adsorption rate.

[0062] Test Example 2

[0063] The styrene anion exchange resins prepared in the examples and comparative examples were boiled in boiling water for 500 hours, and the decrease in their alkali exchange capacity was measured. Specific data are shown in Table 2.

[0064] Table 2 Heat resistance test results of styrene anion resin

[0065] Experimental protocol Alkali exchange capacity loss rate / % Example 1 15.2 Example 2 12.0 Example 3 10.7 Comparative Example 1 38.5 Comparative Example 2 24.2

[0066] Styrene resins use polystyrene as the skeleton and are combined with small molecular functional groups in the form of chemical bonds. Although this structure retains the various excellent properties of the original low molecular weight and adds new functions due to the high molecular weight effect, the thermal stability of polystyrene itself is relatively poor, which limits the heat resistance of the entire resin.

[0067] Compared with reference example 1, the heat resistance of the anionic resin in reference example 2 and the embodiment is obviously better, which may be due to the fact that in other examples, the styrene white ball is chlorinated and aminized, and then reacted with isocyanate pyridine or other functional monomers to carry out functionalization, thereby obtaining a styrene anionic resin with a functional group. When the groups contained in isocyanate pyridine are different, the performance of the resin is also different. Due to nucleophilic addition of isocyanate pyridine and amino, the obtained styrene anionic resin has amide and pyridine groups. Since the hydrogen bond associating ability between amide molecules is strong, and the polarity of amide molecules is large, pyridine is a kind of aromatic heterocycle, and the introduction of the two also improves the heat resistance of the resin at the same time. The pyridine heterocycle in embodiment 3 is the most, and it also has an amide group, so its heat resistance is the best.

[0068] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for preparing a styrene-based anionic resin for hydrometallurgy, characterized in that: The steps include: S1, mixing styrene, porogen and divinylbenzene, then adding initiator, mixing evenly to obtain oil phase; S2, adding gelatin, boric acid and sodium hydroxide to water, adding sodium lignin sulfonate and sodium chloride after heating, and mixing well to obtain an aqueous phase; S3, mixing the oil phase and the water phase evenly, continuing to keep warm and stir for 4 to 6 hours after the gel point appears, raising the temperature and stirring to polymerize to obtain styrene white balls; S4, mixing anhydrous ferric chloride and chloromethyl ether, adding styrene white balls and chlorosulfonic acid, heating and stirring, then cooling, filtering to obtain chlorine balls; S5. After swelling the chlorine ball, wash it with water, mix it with sodium hydroxide and tetrabutylammonium bromide in water, then perform amination, filter and wash it, then mix it with isocyanate pyridine in a solvent, wash it after reaction, and dry it to obtain a styrene anion resin for hydrometallurgy.

2. The method for preparing a styrene-based anion resin for hydrometallurgy according to claim 1, characterized in that: The porogen is isobutanol.

3. The method for preparing a styrene-based anionic resin for hydrometallurgy according to claim 1, wherein the initiator is benzoyl peroxide.

4. The method for preparing a styrene-based anion resin for hydrometallurgy according to claim 1, characterized in that: The mass ratio of the styrene, porogen, divinylbenzene and initiator is 7-8:1:1-2:0.01-0.

02.

5. The method for preparing a styrene-based anion resin for hydrometallurgy according to claim 1, characterized in that: The mass ratio of the gelatin, boric acid and sodium hydroxide, sodium lignin sulfonate, sodium chloride and water is 0.2-0.4:0.2-0.3:0.1-0.2:0.05-0.1:2.5-3:

100.

6. The method for preparing a styrene-based anion resin for hydrometallurgy according to claim 1, characterized in that: The mass ratio of the anhydrous ferric chloride to chloromethyl ether, styrene white balls and chlorosulfonic acid is 0.01-0.015:1-1.5:1:0.005-0.

01.

7. The method for preparing a styrene-based anion resin for hydrometallurgy according to claim 1, characterized in that: The following steps are involved: S1. Mix styrene, porogen and divinylbenzene, add initiator, stir at 20-30°C for 0.5-1h, mix evenly, and obtain oil phase; S2, add gelatin, boric acid and sodium hydroxide to water, raise the temperature to 75-80°C, add sodium lignin sulfonate, continue to raise the temperature to 80-85°C, add sodium chloride, mix well to obtain an aqueous phase; S3, mixing the oil phase and the water phase evenly, stirring at 80-82°C until the gel point appears, and then keeping the temperature and stirring for 4-6 hours, then heating to 85-90°C, keeping the temperature and stirring for 1-3 hours to polymerize, filtering after the reaction, washing, drying, and sieving the obtained styrene white balls for the next step; S4, mix anhydrous ferric chloride and chloromethyl ether, stir until dissolved, add styrene white balls, add chlorosulfonic acid at 20-30°C, heat to 40-45°C, keep stirring for 8-12h, then cool to 20-30°C, filter, wash and dry the obtained chlorine balls for the next step; S5. Add the chlorine ball to 8 to 12 times the weight of dioxane to swell it, then wash it with water, add it to water, add sodium hydroxide and tetrabutylammonium bromide, heat it to 80 to 85°C and add ethylenediamine, filter it after amination for 8 to 14 hours, wash it and add it to 20 to 30 times the weight of the chlorine ball in dichloromethane, mix it with isocyanate pyridine, react it at 20 to 30°C for 14 to 24 hours, filter it, wash it and dry it to obtain the styrene anion resin for hydrometallurgy.

8. The method for preparing a styrene-based anion resin for hydrometallurgy according to claim 7, characterized in that: The mass ratio of the chlorine ball to sodium hydroxide, tetrabutylammonium bromide, ethylenediamine and isocyanate pyridine is 1:1-3:0.01-0.1:15-35:0.8-3.

9. The method for preparing a styrene-based anion resin for hydrometallurgy according to claim 7, characterized in that: The isocyanate pyridine is one of 5-isocyanate-2-methylpyridine, 4-(5-isocyanate pentyloxy)-2,6-bis(2-pyridyl)pyridine or 5-isocyanate-2-(2-pyridyl)pyridine.

10. A styrene anion resin for hydrometallurgy, characterized in that: Prepared by the method according to any one of claims 1 to 9.

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