Ion exchange resin and its preparation method and application

Abstract

The present invention belongs to the technical field of environmental protection chemical industry and battery recycling, and provides an ion exchange resin, a preparation method thereof, and an application thereof. The present invention changes the skeleton structure of the macroporous polystyrene resin by performing hydrophilic-lipophilic modification on the macroporous polystyrene resin. The skeleton structure of the prepared ion exchange resin contains both hydrophilic and lipophilic groups, and can selectively enrich the extractant in the metal liquid recovered from lithium batteries, thereby realizing resource recovery of the extractant, improving the purity of the valuable metal ions in the metal liquid recovered from lithium batteries, and reducing the amount of the extractant used.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental protection chemical industry and battery recycling, and relates to an ion exchange resin and a preparation method thereof, and an application thereof in an extractant for separating and recycling metal liquid recovered from lithium batteries. Background Art

[0002] With the continued expansion of markets such as new energy vehicles and energy storage, the application of lithium batteries is also growing. The market prices of key metal materials such as lithium, nickel, cobalt, and manganese required for their manufacture remain high. As lithium batteries age, an increasing number of used lithium batteries are facing retirement. These retired lithium batteries, rich in various valuable metals, are both excellent energy materials and a significant environmental burden.

[0003] Waste lithium batteries contain a large amount of valuable metals, such as lithium (Li), cobalt (Co), nickel (Ni), manganese (Mn), copper (Cu), aluminum (Al), and iron (Fe). A typical scrapped lithium battery contains 5-20% Co, 5-7% Li, 5-7% Ni, and significant amounts of other valuable metals, such as Mn. The content of valuable metals in waste lithium batteries is significantly higher than that found in natural minerals. Co and Ni are not only rare metals but also important strategic resources. Therefore, the proper recycling of waste lithium batteries is both environmentally friendly and economically beneficial.

[0004] The recycling process for used lithium batteries generally requires crushing, disassembling, sorting, and recycling. When recovering metal elements such as lithium, nickel, cobalt, and manganese from used lithium batteries, appropriate extraction agents are primarily used for extraction and recovery. Organophosphoric acid extractants are the most widely used commercially, including di(2-ethylhexyl)phosphonic acid (P204), 2-ethylhexylphosphonic acid mono(2-ethylhexyl) ester (P507), and bis(2,4,4-trimethylpentyl)phosphonic acid (Cyanex272, Cy272). However, the metal solution containing metal ions such as lithium, nickel, cobalt, and manganese (i.e., the metal solution from lithium battery recycling) extracted with existing extractants often contains some residual extractant. This residual extractant is difficult to remove, resulting in reduced purity and waste of the extractant. To further improve the purity of metal ions, current lithium battery recycling technologies mostly employ multi-stage extraction to increase the metal ion content in the metal solution while also removing trace amounts of residual extractant. However, multi-stage extraction is a cumbersome and costly process. Furthermore, repeated extractions increase the amount of extractant used and result in the loss of some valuable metal ions, further increasing the processing burden and costs.

[0005] Therefore, how to separate the trace amount of extractant in the metal slurry recovered from lithium batteries, realize the resource recovery of the extractant and improve the purity of valuable metal ions has become an important technical problem to be solved by those skilled in the art. Summary of the Invention

[0006] In order to solve the problems in the above-mentioned prior art of low purity of valuable metal ions in lithium battery recovered metal liquid, large amount of extractant used and inability to recover the extractant, the present invention provides an ion exchange resin and a preparation method and application thereof. The ion exchange resin can selectively enrich the extractant in the lithium battery recovered metal liquid, realize resource recovery of the extractant, improve the purity of the valuable metal ions in the lithium battery recovered metal liquid, and reduce the amount of extractant used.

[0007] The present invention is achieved through the following technical solutions:

[0008] In a first aspect, the present invention provides a method for preparing an ion exchange resin, comprising:

[0009] S1, mixing and swelling chloromethylated macroporous polystyrene resin beads (hereinafter referred to as chlorospheres), a hydrophilic reagent, and a solvent, and then heating to react. After the reaction is complete, the resulting resin is washed with water until neutral, the pH value is adjusted to 11-12, and after stabilization for a preset time, it is washed with water until neutral. The resulting resin is recorded as PA resin; the hydrophilic reagent is one or more of aminosulfonic acid, p-aminobenzenesulfonic acid, and p-aminobenzoic acid;

[0010] S2, mixing and swelling the PA resin with the amination reagent solution, and then heating to react. After the reaction is completed, the obtained resin is first washed with the first organic solvent and then washed with water until neutral. The obtained resin is recorded as PAS resin;

[0011] S3, mix and swell the PAS resin with the second organic solvent, adjust the pH value to 8-9.5, and then add C6-C 20 The halogenated long-chain alkane (as a lipophilic reagent) is heated to react, and the resulting resin is first washed with a second organic solvent and then washed with water until neutral. The resulting resin is recorded as PASW resin, that is, the ion exchange resin of the present invention.

[0012] The method for preparing the ion exchange resin of the present invention employs a hydrophilic reagent to react with the chloromethyl groups on the chlorine balls, thereby achieving hydrophilic modification. An aminating reagent is then used to aminate the residual chloromethyl groups on the PA resin, and the resulting amino groups further react with halogenated long-chain alkanes, thereby achieving lipophilic modification. First, the resulting ion exchange resin contains hydrophilic groups (sulfonic acid or carboxylic acid groups) on its backbone structure, which can form hydrogen bonds with water molecules in the lithium battery recovered metal solution. This allows the lithium battery recovered metal solution containing the extractant to rapidly diffuse into the resin interior, increasing the effective contact between the ion exchange resin and the lithium battery recovered metal solution. Second, the lipophilic groups on the ion exchange resin's backbone structure enable hydrophobic interactions with the extractant in the lithium battery recovered metal solution, rapidly concentrating the extractant in the lithium battery recovered metal solution, thereby achieving the purpose of removing the extractant.

[0013] Preferably, the chlorine balls selected in the present invention have an effective chlorine content of 18wt% to 21wt% and a water content of less than 3wt%.

[0014] Preferably, in S1 of the present invention, the mass ratio of the hydrophilic reagent to the chloromethylated macroporous polystyrene resin beads is (0.03-0.1):1.

[0015] Preferably, in S1 of the present invention, the solvent is one of water, ethanol, dimethyl sulfoxide and ethyl acetate.

[0016] Preferably, in S1 of the present invention, the swelling time is 5-10 hours, the reaction temperature is 40-50°C, the reaction time is 3-6 hours, and the residual chlorine content is controlled between 11wt% and 15wt%. After washing with water until neutral, a 20wt% to 30wt% sodium hydroxide solution is added dropwise, the pH is adjusted to 11-12, and the mixture is allowed to stabilize for 2-4 hours. Finally, the mixture is washed with water again until neutral to obtain a PA resin. Controlling the residual chlorine content within a certain range ensures that the resulting PA resin contains a certain amount of hydrophilic groups in its backbone structure and that sufficient chloromethyl groups are available for subsequent reaction with the amination reagent. Adjusting the pH to 11-12 and stabilizing for 2-4 hours can, on the one hand, neutralize the hydrogen chloride produced during the reaction, and on the other hand, make the reaction system alkaline, reducing the amount of amination reagent required for the subsequent amination reaction.

[0017] Preferably, in S2 of the present invention, the amination reagent is one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine; the reaction temperature is 80-120° C., and the reaction time is 10-20 hours.

[0018] Preferably, in S2 of the present invention, the first organic solvent is one of methanol, ethanol, ethyl acetate and acetone; the washing temperature of the first organic solvent is 50-70° C., and the washing time is 2-4 hours.

[0019] Preferably, in S3 of the present invention, the second organic solvent is one of ethanol, ethylene glycol, methylcyclohexane, dimethyl sulfoxide, n-butanol, 1,4-dioxane and N,N-dimethylformamide.

[0020] More preferably, in S3 of the present invention, the second organic solvent used for washing is selected from one of ethylene glycol, ethanol and dimethyl sulfoxide.

[0021] Preferably, in S3 of the present invention, the halogenated long-chain alkane is brominated n-octane, brominated n-decane or brominated n-hexane; and the mass ratio of the halogenated long-chain alkane to the chloromethylated macroporous polystyrene resin beads is (0.2-0.45):1.

[0022] Preferably, in S3 of the present invention, the reaction temperature is 70-90° C., and the reaction time is 10-20 hours.

[0023] Taking the hydrophilic reagent as p-aminobenzenesulfonic acid, the aminating reagent as diethylenetriamine, and the lipophilic reagent as n-octane bromide as an example, the reaction mechanism of the ion exchange resin preparation method of the present invention is as follows, wherein: Indicates a broken bond.

[0024]

[0025] In a second aspect, the present invention provides an ion exchange resin obtained by the preparation method described above.

[0026] In a third aspect, the present invention provides the use of the ion exchange resin as an extractant in separating and recovering metal liquid recovered from lithium batteries.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention's method for preparing the ion exchange resin utilizes a hydrophilic reagent to react with the chloromethyl groups on the chlorine balls, thereby achieving hydrophilic modification. An aminating reagent is then used to aminate the residual chloromethyl groups on the PA resin, and the resulting amino groups further react with halogenated long-chain alkanes, thereby achieving lipophilic modification. Thus, the present invention alters the macroporous polystyrene resin's skeletal structure by performing a hydrophilic-lipophilic modification.

[0029] The skeleton structure of the ion exchange resin prepared by the present invention contains both hydrophilic groups and lipophilic groups. The hydrophilic groups can form hydrogen bonds with water molecules in the lithium battery recycling metal liquid, so that the lithium battery recycling metal liquid containing the extractant can quickly diffuse into the interior of the ion exchange resin, increasing the effective contact between the ion exchange resin and the lithium battery recycling metal liquid. At the same time, the lipophilic groups on the skeleton structure of the ion exchange resin can undergo hydrophobic interactions with the extractant in the lithium battery recycling metal liquid, rapidly enriching the extractant in the lithium battery recycling metal liquid, thereby achieving the purpose of removing the extractant. As more and more extractant is enriched on the ion exchange resin, the extractant molecular clusters will gradually become larger. When they grow to a certain extent, oil droplets will form inside and on the surface of the ion exchange resin. The oil droplets dissolve in hot water and can be directly desorbed using hot water, thereby achieving the regeneration of the ion exchange resin and avoiding the use of acid, alkali and organic solvents. After the desorption liquid is cooled, the resource recovery of the extractant can be achieved through oil-water separation. The ion exchange resin of the present invention has high selectivity for the extractant and high processing precision. It can reduce the extractant in the metal liquid recovered from lithium batteries to below 1 mg / L. It is easy to industrialize and can not only selectively enrich the extractant in the metal liquid recovered from lithium batteries to achieve resource recovery of the extractant, but also improve the purity of the valuable metal ions in the metal liquid recovered from lithium batteries, thereby solving technical problems such as the high cost of valuable metal recovery from lithium batteries, the large amount of extractant used, and the inability to recover the extractant. In particular, the ion exchange resin of the present invention is not only suitable for removing and recovering the extractant in the waste lithium battery liquid, but also can effectively remove and recover the extractant in the liquid produced during the wet extraction process of valuable metals such as lithium, nickel, cobalt, and manganese. DETAILED DESCRIPTION

[0030] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0031] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0032] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or apparatuses. Furthermore, unless otherwise specified, the numbering of each method step is merely a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be considered within the scope of the invention.

[0033] It should be noted that, in the present invention, the macroporous polystyrene resin beads refer to macroporous resins prepared using styrene as a polymerization monomer. Macroporous resin is a term well known to those skilled in the art. Macroporous resins are prepared by the following method: first, a polymerization monomer, a crosslinker, a porogen, and an initiator are polymerized to form a resin. The porogen is then removed from the resin, leaving pores in the resin. The resulting resin is called a macroporous resin.

[0034] In addition, "PA", "PAS", "PASW", "PS", and "PSW" in the present invention are only used to distinguish resins prepared by different methods and have no special meaning.

[0035] The preparation method of the chlorine balls with an effective chlorine content of 18.6 wt% and a water content of 2.5 wt% used in the present invention is as follows:

[0036] (1) Preparation of macroporous polystyrene resin beads:

[0037] 1) Prepare an oil phase solution in a beaker: 90 g styrene, 10 g divinylbenzene (80% by weight), 60 g isobutyl alcohol, and 0.8 g benzoyl peroxide. Stir well.

[0038] 2) Add 500 mL of saturated brine, 3 g of gelatin, 0.5 g of sodium carboxymethyl cellulose, and 5 mL of 0.1 wt% methylene blue solution to a 1-liter three-necked flask and completely dissolve all components at 45°C to prepare an aqueous solution. Add the oil phase solution to the aqueous solution and let it stand for 5 minutes. Start stirring and adjust the stirring speed to control the particle size. Heat to 82°C at 5°C / 10 min for 4 hours, then heat to 88°C for 6 hours.

[0039] 3) After the reaction is completed, the temperature is raised to 92°C to distill out most of the isobutanol, and then the temperature is raised to 100°C and boiled for 4 hours. Finally, the beads are washed with a large amount of water, dried, and sieved to obtain macroporous polystyrene beads with a particle size of 0.3-1.0 mm.

[0040] (2) Preparation of chloromethylated macroporous polystyrene resin beads (chlorine balls):

[0041] 50 g of the prepared macroporous polystyrene beads were added to a dry 1-liter three-necked flask, and then 350 mL of chloromethyl ether was added. The mixture was stirred at room temperature for swelling for 4 hours. After the swelling was completed, 12.5 g of anhydrous ferric chloride was added, and the temperature was raised to 40°C for reaction for 60 hours. Finally, the mother liquor was filtered and washed with water until neutral. The chlorine content was detected by the Volhard method and was 18.6 wt%. The water content was detected by drying at 60°C and was 2.5 wt%, thereby obtaining chloromethylated macroporous polystyrene resin beads.

[0042] The chlorine balls with other effective chlorine contents and water contents used in the embodiments of the present invention can be prepared according to the above-mentioned preparation method of the chlorine balls by simply adjusting the reaction temperature, reaction time or amount of anhydrous ferric chloride for chloromethylation. This belongs to the conventional technology in this field and will not be repeated here.

[0043] Example 1

[0044] A method for preparing an ion exchange resin for separating and recovering an extractant from a metal recovery solution of a lithium battery comprises the following steps:

[0045] 1) Use chlorine balls with an effective chlorine content of 18.6wt% and a water content of 2.5wt%;

[0046] 2) Add 100 g of chlorine balls, 500 mL of deionized water, and 10 g of aminosulfonic acid to a 1000 mL three-necked flask, stir and swell for 10 hours, then heat to 40°C and react for 6 hours. After the reaction, the residual chlorine content of the obtained resin is 13.8 wt %. Wash the obtained resin with deionized water until neutral, add 30 wt % sodium hydroxide solution dropwise, adjust the pH to 12, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is recorded as PA resin;

[0047] 3) adding the PA resin obtained in step 2) into 500 mL of diethylenetriamine solution, allowing it to swell for 3 hours, heating it to 80° C., and reacting it for 20 hours to obtain an amination mother solution containing the resin;

[0048] 4) Filter the amination mother liquor containing the resin, add 400 mL of methanol to the obtained resin, heat to 50°C, stir and wash for 4 hours, then filter the methanol washing liquid, and wash the obtained resin with deionized water until neutral. The obtained resin is recorded as PAS resin;

[0049] 5) The PAS resin obtained in step 4) was added to ethanol for swelling. After swelling for 6 hours, solid sodium hydroxide was added to adjust the pH to 9.5. The specific amount of sodium hydroxide used was determined by the pH. 30 g of n-octane bromide was then added, and the temperature was raised to 70° C. for reaction for 20 hours to obtain an ethanol mother liquor containing the resin.

[0050] 6) Filter the ethanol mother liquor containing the resin, wash it with ethanol and deionized water in sequence until it is neutral, and discharge the material. The obtained ion exchange resin is recorded as PASW resin.

[0051] Example 2

[0052] A method for preparing an ion exchange resin for separating and recovering an extractant from a metal recovery solution of a lithium battery comprises the following steps:

[0053] 1) Use chlorine balls with an effective chlorine content of 19.2wt% and a water content of 2.2wt%;

[0054] 2) Add 100 g of chlorine balls, 500 mL of dimethyl sulfoxide, and 6 g of p-aminobenzenesulfonic acid to a 1000 mL three-necked flask, stir and swell for 7 hours, then heat to 50°C and react for 4 hours. After the reaction, the residual chlorine content of the obtained resin is 14.9 wt %. Wash the obtained resin with deionized water until neutral, add 30 wt % sodium hydroxide solution dropwise, adjust the pH to 11, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is recorded as PA resin;

[0055] 3) adding the PA resin obtained in step 2) into 500 mL of tetraethylenepentamine solution, allowing it to swell for 3 hours, heating it to 110° C., and reacting it for 13 hours to obtain an amination mother liquor containing the resin;

[0056] 4) Filter the amination mother liquor containing the resin, add 400 mL of ethanol to the obtained resin, heat to 55°C, stir and wash for 3 hours, then filter the ethanol washing liquid, and wash the obtained resin with deionized water until neutral. The obtained resin is recorded as PAS resin;

[0057] 5) The PAS resin obtained in step 4) was added to ethylene glycol for swelling. After swelling for 6 hours, solid sodium hydroxide was added to adjust the pH to 8 (the specific amount of sodium hydroxide used depends on the pH). 30 g of n-decyl bromide was then added, and the temperature was raised to 80° C. for reaction for 10 hours to obtain an ethylene glycol mother liquor containing the resin.

[0058] 6) Filter the ethylene glycol mother liquor containing the resin, wash it with ethylene glycol and deionized water in sequence until it is neutral, and discharge the material. The obtained ion exchange resin is recorded as PASW resin.

[0059] Example 3

[0060] A method for preparing an ion exchange resin for separating and recovering an extractant from a metal recovery solution of a lithium battery comprises the following steps:

[0061] 1) Use chlorine balls with an effective chlorine content of 18.6wt% and a water content of 2.5wt%;

[0062] 2) Add 100 g of chlorine balls, 500 mL of ethyl acetate, and 5 g of p-aminobenzoic acid to a 1000 mL three-necked flask, stir and swell for 8 hours, then heat to 45°C and react for 5 hours. After the reaction, the residual chlorine content of the obtained resin is 13.8 wt %. Wash the obtained resin with deionized water until neutral, add 20 wt % sodium hydroxide solution dropwise, adjust the pH to 11.5, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is recorded as PA resin;

[0063] 3) adding the PA resin obtained in step 2) into 500 mL of ethylenediamine solution, allowing it to swell for 3 hours, heating it to 100° C., and reacting it for 15 hours to obtain an amination mother solution containing the resin;

[0064] 4) Filter the amination mother liquor containing the resin, add 400 mL of ethyl acetate to the obtained resin, heat to 60°C, stir and wash for 3 hours, then filter the ethyl acetate washing liquid, and wash the obtained resin with deionized water until neutral. The obtained resin is recorded as PAS resin;

[0065] 5) The PAS resin obtained in step 4) was added to dimethyl sulfoxide for swelling. After swelling for 6 hours, solid sodium hydroxide was added to adjust the pH to 9 (the specific amount of sodium hydroxide used depends on the pH). 20 g of n-bromohexane was then added, and the temperature was raised to 80° C. for reaction for 15 hours to obtain a dimethyl sulfoxide mother liquor containing the resin.

[0066] 6) Filter the dimethyl sulfoxide mother liquor containing the resin, then wash it with dimethyl sulfoxide and deionized water in sequence until it is neutral, and discharge the material. The obtained ion exchange resin is recorded as PASW resin.

[0067] Example 4

[0068] A method for preparing an ion exchange resin for separating and recovering an extractant from a metal recovery solution of a lithium battery comprises the following steps:

[0069] 1) Use chlorine balls with an effective chlorine content of 18.6wt% and a water content of 2.5wt%;

[0070] 2) Add 100 g of chlorine balls, 500 mL of dimethyl sulfoxide, and 3 g of p-aminobenzenesulfonic acid to a 1000 mL three-necked flask, stir and swell for 5 hours, then heat to 50°C and react for 3 hours. After the reaction, the residual chlorine content of the obtained resin is 13.5 wt %. Wash the obtained resin with deionized water until neutral, add 30 wt % sodium hydroxide solution dropwise, adjust the pH to 11, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is recorded as PA resin;

[0071] 3) adding the PA resin obtained in step 2) into 500 mL of triethylenetetramine solution, allowing it to swell for 3 hours, heating it to 120° C., and reacting it for 10 hours to obtain an amination mother solution containing the resin;

[0072] 4) Filter the amination mother liquor containing the resin, add 400 mL of ethanol to the obtained resin, heat to 70°C, stir and wash for 2 hours, then filter the ethanol washing liquid, and wash the obtained resin with deionized water until neutral. The obtained resin is recorded as PAS resin;

[0073] 5) The PAS resin obtained in step 4) was added to ethylene glycol for swelling. After swelling for 6 hours, solid sodium hydroxide was added to adjust the pH to 8. The specific amount of sodium hydroxide used was determined by the pH. 45 g of n-decyl bromide was then added, and the temperature was raised to 90° C. for reaction for 10 hours to obtain an ethylene glycol mother liquor containing the resin.

[0074] 6) Filter the ethylene glycol mother liquor containing the resin, wash it with ethylene glycol and deionized water in sequence until it is neutral, and discharge the material. The obtained ion exchange resin is recorded as PASW resin.

[0075] Example 5

[0076] A method for preparing an ion exchange resin for separating and recovering an extractant from a metal recovery solution of a lithium battery comprises the following steps:

[0077] 1) Use chlorine balls with an effective chlorine content of 18.8wt% and a water content of 2.3wt%;

[0078] 2) Add 100 g of chlorine balls, 500 mL of deionized water, and 8 g of aminosulfonic acid to a 1000 mL three-necked flask, stir and swell for 6 hours, then heat to 47°C and react for 6 hours. After the reaction, the residual chlorine content of the obtained resin is 14.3 wt %. Wash the obtained resin with deionized water until neutral, add 30 wt % sodium hydroxide solution dropwise, adjust the pH to 12, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is recorded as PA resin;

[0079] 3) adding the PA resin obtained in step 2) into 500 mL of pentaethylenehexamine solution, allowing it to swell for 3 hours, heating it to 120° C., and reacting it for 12 hours to obtain an amination mother solution containing the resin;

[0080] 4) Filter the amination mother liquor containing the resin, add 400 mL of methanol to the obtained resin, heat to 65°C, stir and wash for 4 hours, then filter the methanol washing liquid, and wash the obtained resin with deionized water until neutral. The obtained resin is recorded as PAS resin;

[0081] 5) The PAS resin obtained in step 4) was added to ethanol to swell. After swelling for 6 hours, solid sodium hydroxide was added to adjust the pH to 9.5. The specific amount of sodium hydroxide used was determined by the pH. 25 g of n-octane bromide was then added, and the temperature was raised to 75° C. to react for 13 hours to obtain an ethanol mother liquor containing the resin.

[0082] 6) Filter the ethanol mother liquor containing the resin, wash it with ethanol and deionized water in sequence until it is neutral, and discharge the material. The obtained ion exchange resin is recorded as PASW resin.

[0083] Example 6

[0084] A method for preparing an ion exchange resin for separating and recovering an extractant from a metal recovery solution of a lithium battery comprises the following steps:

[0085] 1) Use chlorine balls with an effective chlorine content of 19.0% and a water content of 1.9%;

[0086] 2) Add 100 g of chlorine balls, 500 mL of ethyl acetate, and 8 g of p-aminobenzoic acid to a 1000 mL three-necked flask, stir and swell for 6 hours, then heat to 47°C and react for 6 hours. After the reaction, the residual chlorine content of the obtained resin is 11 wt %. Wash the obtained resin with deionized water until neutral, add 20 wt % sodium hydroxide solution dropwise, adjust the pH to 11.5, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is recorded as PA resin;

[0087] 3) adding the PA resin obtained in step 2) into 500 mL of ethylenediamine solution, allowing it to swell for 3 hours, heating it to 90° C., and reacting it for 17 hours to obtain an amination mother liquor containing the resin;

[0088] 4) Filter the amination mother liquor containing the resin, add 400 mL of ethyl acetate to the obtained resin, heat to 50°C, stir and wash for 2 hours, then filter the ethyl acetate washing liquid, and wash the obtained resin with deionized water until neutral. The obtained resin is recorded as PAS resin;

[0089] 5) The PAS resin obtained in step 4) was added to dimethyl sulfoxide for swelling. After swelling for 6 hours, solid sodium hydroxide was added to adjust the pH to 9 (the specific amount of sodium hydroxide used depends on the pH). 35 g of n-bromohexane was then added, and the temperature was raised to 85° C. for reaction for 17 hours to obtain a dimethyl sulfoxide mother liquor containing the resin.

[0090] 6) Filter the dimethyl sulfoxide mother liquor containing the resin, then wash it with dimethyl sulfoxide and deionized water in sequence until it is neutral, and discharge the material. The obtained ion exchange resin is recorded as PASW resin.

[0091] Comparative Example 1

[0092] The method for preparing the resin of this comparative example comprises the following steps:

[0093] 1) Use chlorine balls with an effective chlorine content of 18.6wt% and a water content of 2.5wt%;

[0094] 2) Add 100 g of chlorine balls, 500 mL of deionized water, and 10 g of aminosulfonic acid to a 1000 mL three-necked flask, stir and swell for 10 hours, then heat to 40°C and react for 6 hours. After the reaction, the residual chlorine content of the obtained resin is 13.8 wt %. Wash the obtained resin with deionized water until neutral, add 30 wt % sodium hydroxide solution dropwise, adjust the pH to 12, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is recorded as PA resin;

[0095] 3) adding the PA resin obtained in step 2) into 500 mL of diethylenetriamine solution, allowing it to swell for 3 hours, heating it to 80° C., and reacting it for 20 hours to obtain an amination mother solution containing the resin;

[0096] 4) Filter the amination mother liquor containing the resin, add 400 mL of methanol to the obtained resin, heat to 50°C, stir and wash for 4 hours, then filter the methanol washing liquid, and wash the obtained resin with deionized water until it is neutral. The obtained resin is recorded as PAS resin.

[0097] Comparative Example 2

[0098] The method for preparing the resin of this comparative example comprises the following steps:

[0099] 1) Use chlorine balls with an effective chlorine content of 18.6wt% and a water content of 2.5wt%;

[0100] 2) Add 100g of chlorine balls and 500mL of diethylenetriamine solution to a 1000mL three-necked flask, allow to swell for 3 hours, then heat to 80°C and react for 20 hours to obtain an amination mother liquor containing resin;

[0101] 3) Filter the amination mother liquor containing the resin, add 400 mL of methanol to the obtained resin, heat to 50°C, stir and wash for 4 hours, then filter the methanol washing liquid, and wash the obtained resin with deionized water until neutral. The obtained resin is recorded as PS resin;

[0102] 4) The PS resin obtained in step 3) was added to ethanol for swelling. After swelling for 6 hours, solid sodium hydroxide was added to adjust the pH to 9.5. The specific amount of sodium hydroxide used was determined by the pH. 30 g of n-octane bromide was then added, and the temperature was raised to 70° C. for reaction for 20 hours to obtain an ethanol mother liquor containing the resin.

[0103] 5) Filter the ethanol mother liquor containing the resin, wash it with ethanol and deionized water in sequence until it is neutral, and discharge the material. The obtained resin is recorded as PSW resin.

[0104] Comparative Example 3

[0105] The resin preparation method of this comparative example comprises the following steps:

[0106] 1) Use chlorine balls with an effective chlorine content of 18.6wt% and a water content of 2.5wt%;

[0107] 2) Add 100g of chlorine balls and 500mL of diethylenetriamine solution to a 1000mL three-necked flask, allow to swell for 3 hours, then heat to 80°C and react for 20 hours to obtain an amination mother liquor containing resin;

[0108] 3) Filter the amination mother liquor containing the resin, add 400 mL of methanol to the obtained resin, heat to 50°C, stir and wash for 4 hours, then filter the methanol washing liquid and wash with deionized water until neutral. The obtained resin is recorded as PS resin.

[0109] In order to verify the technical effect achieved by the present invention, the present invention prepared three groups of control samples, namely, Comparative Example 1, Comparative Example 2 and Comparative Example 3. That is, based on Example 1, Comparative Example 1 was only hydrophilic modified and not lipophilic modified, Comparative Example 2 was only lipophilic modified and not hydrophilic modified, and Comparative Example 3 was neither hydrophilic nor lipophilic modified.

[0110] The performance indicators of the resins obtained in the embodiments of the present invention and the comparative examples are shown in Table 1.

[0111]

[0112] The performance indicators of Examples 1-6 in Table 1 demonstrate that, first, the hydrophilic modification of the macroporous polystyrene resin using a hydrophilic reagent containing sulfonic acid and carboxyl groups demonstrates successful grafting of the hydrophilic reagent into the PA resin backbone, as evidenced by the weak acid exchange capacity (greater than 1.0 mmol / g) of the PA resin. Furthermore, the residual chlorine content of the PA resin indicates that the hydrophilic reagent reacted with the chloromethyl groups, consuming some of the chloromethyl groups, resulting in the PA resin containing a certain amount of hydrophilic groups. Secondly, the amination of the PA resin using an aminating reagent further enhances the resin's hydrophilicity. The weak base exchange capacity (greater than 5.5 mmol / g) of the PAS resin indicates that the amino groups in the aminating reagent react with the residual chloromethyl groups, imparting a certain amount of hydrophilic groups to the PAS resin. Furthermore, the use of an aminating reagent containing at least two amino groups in the present invention ensures that the resin's hydrophilicity is enhanced while retaining some amino groups, paving the way for the subsequent lipophilic modification of the PAS resin. Finally, the oleophilic modification of PAS resin using a halogenated long-chain alkane containing a long-chain alkane reduces the weak-base exchange capacity of the PASW resin, demonstrating that amino groups react with the halogenated long-chain alkane, consuming some of the amino groups and resulting in a certain amount of oleophilic groups within the ion exchange resin's backbone structure. Compared to Example 1, Comparative Example 2 lacks sulfonic acid groups. Therefore, the weak-base exchange capacity of the PS resin in this example is higher than that of the PAS resin in Example 1. This also demonstrates that the present resin synthesis process successfully prepared an ion exchange resin containing hydrophilic groups.

[0113] In order to further verify the removal effect of the ion exchange resin prepared by the present invention on the extractant in the lithium battery recovery metal solution, and at the same time, compare with the comparative example to verify the removal effect of the ion exchange resin of the present invention on the extractant, a separation experiment was carried out using a prepared nickel sulfate solution containing an organic phosphoric acid extractant (hereinafter referred to as the stock solution). In the present invention, the organic phosphoric acid extractant is bis(2,4,4-trimethylpentyl)phosphoric acid. The nickel sulfate solution is green, has a pH value of 5-6, a nickel sulfate concentration of 105 g / L, and an extractant content of 100 mg / L.

[0114] The specific experimental methods are as follows:

[0115] 1) Pretreatment: 80 mL of wet sample of each resin sample prepared in each embodiment of the present invention and each comparative example was taken and placed into a glass chromatography column, which was tapped solid. The column was then pretreated with 3 volumes of 10% sulfuric acid solution and then rinsed with deionized water until the pH value at the outlet was neutral, thereby obtaining an ion exchange resin column for use.

[0116] 2) Column flow: Before the experiment, the nickel sulfate solution was stirred for 2 hours to mix evenly, and then passed through the ion exchange resin column at a flow rate of 1 BV / h (i.e., 80 mL / h). Samples were taken every 10 BV and the extractant content was detected using an infrared oil analyzer (see Table 2 for results). A total of 100 BV was processed, and the column flow was stopped. After the column flow was completed, all the effluents were mixed to obtain a 100 BV mixed sample. The extractant content in the 100 BV mixed sample was detected (see Table 2 for results);

[0117] 3) Desorption: When processing 100BV, use 1BV of deionized water to replace the liquid in the ion exchange resin column, and then use 4BV of 80~90℃ hot water to desorb the ion exchange resin column at a flow rate of 0.5BV / h. Collect the desorbed liquid. After the desorbed liquid is cooled, separate the extractant and water, and keep the extractant for later use, thereby achieving the purpose of recovering the extractant.

[0118]

[0119] As can be seen from Table 2, the ion exchange resin prepared by the present invention has a good removal effect on the extractant in the nickel sulfate solution, that is, the extractant in the nickel sulfate solution is reduced to less than 1 mg / L, 100BV can be stably treated, the removal rate reaches more than 99%, and the adsorption capacity can reach more than 8 g / L, indicating that the ion exchange resin prepared by the present invention can be used to efficiently remove and recover the extractant. This is because the present invention changes the internal structure of the macroporous polystyrene resin after the macroporous polystyrene resin is modified from hydrophilic to lipophilic. The skeleton structure of the obtained ion exchange resin contains hydrophilic groups (such as sulfonic acid groups, carboxylic acid groups and amino groups). On the one hand, it can form hydrogen bonds with water molecules in the nickel sulfate solution, so that the nickel sulfate solution containing the extractant can quickly diffuse into the interior of the ion exchange resin, thereby increasing the effective contact between the ion exchange resin and the nickel sulfate solution; on the other hand, the introduction of sulfonic acid groups or carboxylic acid groups into the skeleton structure of the ion exchange resin can reduce the oil-water interfacial tension of the nickel sulfate solution, increase the surface activity, enhance the oil-water interface competitive separation ability, and change The properties of the oil-water interface film achieve the purpose of demulsification and separate the extractant from the nickel sulfate feed system. At the same time, the ion exchange resin's skeleton structure contains lipophilic groups (such as long-chain alkanes), which can interact hydrophobically with the extractant in the nickel sulfate feed, rapidly enriching the extractant in the nickel sulfate feed, thereby achieving the purpose of removing the extractant. As more and more extractant is enriched on the ion exchange resin skeleton structure, the extractant molecular clusters will gradually grow. When they grow to a certain size, oil droplets will form inside and on the surface of the ion exchange resin. When regenerated with hot water, the oil droplets dissolve in the hot water, thereby achieving regeneration of the ion exchange resin and recovery of the extractant. In Comparative Example 1, only the macroporous polystyrene resin is hydrophilically modified. The resulting ion exchange resin does not contain lipophilic groups of halogenated long-chain alkanes on its skeleton structure. The extractant in the nickel sulfate feed can enter the ion exchange resin, but the hydrophobic interaction between the extractant and the ion exchange resin is weak, resulting in poor separation of the extractant, poor removal accuracy of the extractant, and low adsorption capacity. Comparative Example 2 only modified the macroporous polystyrene resin to make it lipophilic, increasing its hydrophobicity. This made it difficult for the extractant in the nickel sulfate solution to enter the resin. However, due to the presence of certain amino groups in the resin's skeleton structure, the hydrophilicity of the macroporous polystyrene resin was also improved to a certain extent. In actual testing, this method demonstrated a certain degree of extractant removal efficiency with high removal accuracy, but the treatment efficiency was low, making it difficult to commercialize. Comparative Example 3 neither improved the hydrophilicity nor changed the hydrophobicity of the macroporous polystyrene resin. The actual treatment effect was poor extractant removal accuracy and a low treatment efficiency.

[0120] In summary, the present invention successfully prepared an ion exchange resin capable of efficiently removing the extractant from the metal liquid recovered from lithium batteries based on the hydrophobic characteristics of the extractant in the metal liquid recovered from lithium batteries. The comparative experiments of the embodiments and comparative examples verified that the ion exchange resin prepared by the present invention can achieve the removal of the extractant from the metal liquid recovered from lithium batteries and achieve effective recovery of the extractant. The ion exchange resin prepared by the method of the present invention is not only suitable for the removal and recovery of the extractant from the metal liquid recovered from lithium batteries, but also can achieve effective removal and resource recovery of the extractant in the generated liquid during the wet extraction process of valuable metals such as lithium, nickel, cobalt, and manganese.

[0121] The above content is only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing an ion exchange resin, characterized in that: include: S1, mixing and swelling chloromethylated macroporous polystyrene resin beads, a hydrophilic reagent, and a solvent, and then heating to react. After the reaction is completed, the resulting resin is washed with water until neutral, the pH value is adjusted to 11-12, and after stabilization for a preset time, it is washed with water until neutral. The resulting resin is recorded as PA resin; the hydrophilic reagent is one or more of aminosulfonic acid, p-aminobenzenesulfonic acid, and p-aminobenzoic acid; S2, mixing and swelling the PA resin with the amination reagent solution, and then heating to react. After the reaction is completed, the obtained resin is first washed with the first organic solvent and then washed with water until neutral. The obtained resin is recorded as PAS resin; S3, mixing and swelling the PAS resin with the second organic solvent, then adjusting the pH value to 8-9.5, and then adding C6-C 20 The halogenated long-chain alkane is heated to react. After the reaction is completed, the obtained resin is first washed with a second organic solvent and then washed with water until neutral to obtain an ion exchange resin.

2. The method for preparing an ion exchange resin according to claim 1, wherein In S1, the mass ratio of the hydrophilic reagent to the chloromethylated macroporous polystyrene resin beads is (0.03-0.1):

1.

3. The method for preparing the ion exchange resin according to claim 1, wherein In S1, the reaction temperature is 40-50°C, and the reaction time is 3-6 hours.

4. The method for preparing the ion exchange resin according to claim 1, wherein In S2, the amination reagent is one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

5. The method for preparing an ion exchange resin according to claim 1, wherein In S2, the reaction temperature is 80-120° C., and the reaction time is 10-20 hours.

6. The method for preparing an ion exchange resin according to claim 1, wherein In S3, the halogenated long-chain alkane is brominated n-octane, brominated n-decane or brominated n-hexane.

7. The method for preparing an ion exchange resin according to claim 1, wherein In S3, the mass ratio of the halogenated long-chain alkane to the chloromethylated macroporous polystyrene resin beads is (0.2-0.45):

1.

8. The method for preparing an ion exchange resin according to claim 1, wherein In S3, the reaction temperature is 70-90° C., and the reaction time is 10-20 hours.

9. The ion exchange resin obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the ion exchange resin according to claim 9 as an extractant in separating and recovering metal liquid from lithium batteries.

Images