Ion exchange resin as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of environment-friendly chemical industry and battery recovery, and provides an ion exchange resin and a preparation method and application thereof. Macroporous polystyrene resin is subjected to hydrophilic and oleophylic modification, so that the skeleton structure of the macroporous polystyrene resin is changed; the skeleton structure of the prepared ion exchange resin contains hydrophilic groups and lipophilic groups at the same time, the extraction agent in the lithium battery recovery metal liquid can be selectively enriched, resource recovery of the extraction agent is achieved, the purity of valuable metal ions in the lithium battery recovery metal liquid is improved, and the use amount of the extraction agent is reduced.

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 of the same in an extractant for separating and recycling metal liquid recovered from lithium batteries. Background Art

[0002] With the continuous expansion of new energy vehicles, energy storage and other markets, the application scale of lithium batteries is also continuously increasing. The market prices of key metal materials such as lithium, nickel, cobalt, and manganese required for the manufacture of lithium batteries remain high. As the use time of lithium batteries increases, more and more waste lithium batteries are facing "retirement". Retired waste lithium batteries, which are rich in various valuable metals, are both excellent energy materials and a huge 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), iron (Fe), etc. Usually, scrapped lithium batteries contain 5wt%~20wt% Co, 5wt%~7wt% Li, 5wt%~7wt% Ni and a large amount of valuable metals such as Mn. The content of valuable metals in waste lithium batteries is significantly higher than the metal content contained in natural minerals. Co and Ni are not only rare metals, but also important strategic resources. Therefore, the reasonable recycling of waste lithium batteries is not only beneficial to the environment, but also has high economic benefits.

[0004] In the process of recycling waste lithium batteries, it is generally necessary to crush, disassemble, classify, and recycle waste lithium batteries. When recycling metal elements such as lithium, nickel, cobalt, and manganese in waste lithium batteries, suitable extractants are mainly selected for extraction and recovery. Organic phosphoric acid extractants are the most widely used commercial extractants, such as di(2-ethylhexyl)phosphoric acid (P204 for short), 2-ethylhexylphosphonic acid mono(2-ethylhexyl) ester (P507 for short), and bis(2,4,4-trimethylpentyl)phosphoric acid (Cyanex272, Cy272 for short). However, the metal liquid containing metal ions such as lithium, nickel, cobalt, and manganese obtained by the existing extractants (i.e., the metal liquid for lithium battery recycling) usually has some extractants left in it, which is difficult to remove completely, resulting in a reduction in the purity of the metal liquid on the one hand and a waste of the extractant on the other. In the current lithium battery recycling technology, in order to further improve the purity of metal ions, most of them use multi-stage extraction to increase the content of metal ions in the metal liquid, and also remove the trace amount of residual extractant in the metal liquid. However, the multi-stage extraction process is cumbersome and costly, and because of repeated extraction, the amount of extractant used increases and some valuable metal ions are lost, which further increases the processing burden and cost.

[0005] Therefore, how to separate the trace extractant from the lithium battery recycled metal liquor, 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 of low purity of valuable metal ions, large dosage of extractant and inability to recycle the extractant in the lithium battery recycled metal liquor in the above-mentioned prior art, the present invention provides an ion exchange resin, a preparation method thereof and an application thereof. The ion exchange resin can selectively enrich the extractant in the lithium battery recycled metal liquor, realize the resource recovery of the extractant, improve the purity of valuable metal ions in the lithium battery recycled metal liquor and reduce the dosage of the extractant.

[0007] The present invention is realized through the following technical solutions: In a first aspect, the present invention provides a preparation method of an ion exchange resin, comprising: S1. Mix and swell a chloromethylated macroporous polystyrene resin bead (hereinafter referred to as chlorinated bead), a hydrophilic reagent and a solvent, and then heat for reaction. After the reaction is completed, the obtained resin is washed with water until neutral, the pH value is adjusted to 11-12, and after stabilizing for a preset time, it is washed with water until neutral. The obtained resin is denoted as PA resin; the hydrophilic reagent is one or more of sulfamic acid, p-aminobenzenesulfonic acid and p-aminobenzoic acid; S2. Mix and swell the PA resin with a solution of an amination reagent, and then heat for reaction. After the reaction is completed, the obtained resin is first washed with a first organic solvent and then washed with water until neutral. The obtained resin is denoted as PAS resin; S3. Mix and swell the PAS resin with a second organic solvent, adjust the pH value to 8-9.5, and then add a C6-C 20 halogenated long-chain alkane (as a lipophilic reagent), heat for reaction. The obtained resin is first washed with a second organic solvent and then washed with water until neutral. The obtained resin is denoted as PASW resin, which is the ion exchange resin of the present invention.

[0008] In the preparation method of the above ion exchange resin of the present invention, a hydrophilic reagent reacts with the chloromethyl group on the chlorinated resin beads to achieve hydrophilic modification; an amination reagent reacts with the residual chloromethyl group on the PA resin to form an amino group, which further reacts with a halogenated long-chain alkane to achieve lipophilic modification. First, the obtained ion exchange resin has a hydrophilic group (sulfonic acid group or carboxylic acid group) on its skeleton structure, which can form a hydrogen bond with water molecules in the metal feed liquid for lithium battery recycling, enabling the metal feed liquid for lithium battery recycling containing an extractant to quickly diffuse into the resin interior, increasing the effective contact between the ion exchange resin and the metal feed liquid for lithium battery recycling. Second, the skeleton structure of the ion exchange resin contains a lipophilic group, which can undergo a hydrophobic interaction with the extractant in the metal feed liquid for lithium battery recycling, quickly enriching the extractant in the metal feed liquid for lithium battery recycling, thereby achieving the purpose of removing the extractant.

[0009] Preferably, for the chlorinated resin beads selected in the present invention, the effective chlorine content is 18 wt% - 21 wt%, and the water content is less than 3 wt%.

[0010] 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.

[0011] Preferably, in S1 of the present invention, the solvent is one of water, ethanol, dimethyl sulfoxide, and ethyl acetate.

[0012] 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 amount is controlled between 11 wt% - 15 wt%; after washing with water until neutral, a sodium hydroxide solution with a concentration of 20 wt% - 30 wt% is added dropwise to adjust the pH value to 11 - 12 and stabilized for 2 - 4 hours, and finally washed with water until neutral to obtain the PA resin. Controlling the residual chlorine amount within a certain range can not only ensure that the obtained PA resin has a certain hydrophilic group on its skeleton structure but also ensure that there is enough chloromethyl group to react with the amination reagent in the later stage. Adjusting the pH value to 11 - 12 and stabilizing for 2 - 4 hours can, on the one hand, neutralize the hydrogen chloride generated during the reaction, and on the other hand, adjust the reaction system to be alkaline, reducing the amount of amination reagent required for the later amination reaction.

[0013] 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.

[0014] Preferably, in S2 of the present invention, the first organic solvent is one of methanol, ethanol, ethyl acetate, and acetone; the temperature for washing with the first organic solvent is 50 - 70 °C, and the time is 2 - 4 hours.

[0015] Preferably, in step S3 of the present invention, the second organic solvent is one of ethanol, ethylene glycol, methyl cyclohexane, dimethyl sulfoxide, n-butanol, 1,4-dioxane, and N,N-dimethylformamide.

[0016] More preferably, in step S3 of the present invention, the second organic solvent for washing is selected from one of ethylene glycol, ethanol, and dimethyl sulfoxide.

[0017] Preferably, in step S3 of the present invention, the halogenated long-chain alkane is n-octyl bromide, n-decyl bromide, or n-hexyl bromide; the mass ratio of the halogenated long-chain alkane to the chloromethylated macroporous polystyrene resin beads is (0.2~0.45):1.

[0018] Preferably, in step S3 of the present invention, the reaction temperature is 70~90 °C, and the reaction time is 10~20 hours.

[0019] Taking p-aminobenzenesulfonic acid as the hydrophilic reagent, diethylenetriamine as the amination reagent, and n-octyl bromide as the lipophilic reagent as an example, the reaction mechanism of the preparation method of the ion exchange resin of the present invention is as follows, where represents bond breaking.

[0020]

[0021] In the second aspect, the present invention provides an ion exchange resin obtained by the preparation method described above.

[0022] In the third aspect, the present invention provides the application of the ion exchange resin in separating and recovering the extractant in the lithium battery recycling metal liquor.

[0023] Compared with the prior art, the present invention has the following beneficial effects: In the preparation method of the ion exchange resin of the present invention, the hydrophilic reagent reacts with the chloromethyl on the chlorinated beads to achieve hydrophilic modification; the amination reagent reacts with the residual chloromethyl on the PA resin to form an amino group, which further reacts with the halogenated long-chain alkane to achieve lipophilic modification. Therefore, the present invention changes the skeleton structure of the macroporous polystyrene resin by hydrophilic and lipophilic modification of the macroporous polystyrene resin.

[0024] The framework structure of the ion exchange resin prepared by the present invention contains both hydrophilic groups and lipophilic groups at the same time. The hydrophilic groups can form hydrogen bond interactions with water molecules in the metal-containing feed liquid for lithium battery recycling, enabling the metal-containing feed liquid for lithium battery recycling containing the extractant to rapidly diffuse into the interior of the ion exchange resin, increasing the effective contact between the ion exchange resin and the metal-containing feed liquid for lithium battery recycling. At the same time, the lipophilic groups on the framework structure of the ion exchange resin can undergo hydrophobic interactions with the extractant in the metal-containing feed liquid for lithium battery recycling, rapidly enriching the extractant in the metal-containing feed liquid for lithium battery recycling, thereby achieving the purpose of removing the extractant. As more and more extractant accumulates on the ion exchange resin, the extractant molecular clusters will gradually grow larger. When it grows to a certain extent, oil droplets are formed inside and on the surface of the ion exchange resin. The oil droplets are soluble in hot water, and hot water can be directly used for desorption, thereby realizing the regeneration of the ion exchange resin, avoiding the use of acids, alkalis, and organic solvents. After the desorption liquid is cooled, the extractant can be resourcefully recovered through oil-water separation. The ion exchange resin of the present invention has high selectivity for the extractant and high treatment precision, can reduce the extractant in the metal-containing feed liquid for lithium battery recycling to below 1 mg / L, and is easy to industrialize. It can not only selectively enrich the extractant in the metal-containing feed liquid for lithium battery recycling and realize the resourceful recovery of the extractant, but also improve the purity of valuable metal ions in the metal-containing feed liquid for lithium battery recycling, thereby solving the technical problems such as high cost of recycling valuable metals from lithium batteries, large consumption of extractant, and inability to recycle the extractant. In particular, the ion exchange resin of the present invention is not only applicable to the removal and recovery of the extractant in the waste lithium battery feed liquid, but also can effectively remove and resourcefully recover the extractant in the feed liquid generated during the wet extraction process of producing valuable metals such as lithium, nickel, cobalt, and manganese. Detailed Embodiments

[0025] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0026] It should be noted that the process equipment or devices not specifically noted in the following examples are all conventional equipment or devices in the art.

[0027] It should be noted that the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, rather than limiting the arrangement order of each method step or the scope in which the present invention can be implemented. Changes or adjustments to their relative relationships, without substantial changes in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0028] It should be noted that in the present invention, the macroporous polystyrene resin beads refer to macroporous resins prepared using styrene as the polymerization monomer. Macroporous resins are well-known technical terms in the art, and those skilled in the art are familiar with the method for preparing macroporous resins as follows: First, a resin is prepared by subjecting a polymerization monomer, a cross-linking agent, a pore-forming agent, and an initiator to a polymerization reaction. Then, the pore-forming agent in the resin is removed, leaving pores in the resin, and the resulting resin is called a macroporous resin.

[0029] In addition, in the present invention, "PA", "PAS", "PASW", "PS", and "PSW" are only used to distinguish resins prepared by different methods and have no special meaning.

[0030] The preparation method of the chlorine beads 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: (1) Preparation of macroporous polystyrene resin beads: 1) Prepare an oil-phase solution in a beaker: 90 g of styrene, 10 g of divinylbenzene (mass content 80%), 60 g of isobutanol, and 0.8 g of benzoyl peroxide, and stir evenly.

[0031] 2) Add 500 mL of saturated brine, 3 g of gelatin, 0.5 g of sodium carboxymethylcellulose, and 5 mL of 0.1 wt% methylene blue solution to a 1-liter three-necked flask, and completely dissolve each component at 45 °C to prepare an aqueous solution. Add the oil-phase solution to the aqueous solution, let it stand for 5 minutes, start stirring, adjust the stirring speed to control the particle size, and heat it to 82 °C at a rate of 5 °C / 10 min for reaction for 4 hours, and then heat it to 88 °C for reaction for 6 hours.

[0032] 3) After the reaction, heat it to 92 °C to distill out most of the isobutanol, then heat it to 100 °C to boil the beads for 4 hours. Finally, wash them thoroughly with water, dry them, and screen them to obtain macroporous polystyrene beads with a particle size of 0.3 - 1.0 mm.

[0033] (2) Preparation of chloromethylated macroporous polystyrene resin beads (chlorine beads): In a dry 1-L three-necked flask, add 50 g of the macroporous polystyrene beads prepared above, then add 350 mL of chloromethyl ether, stir and swell at room temperature for 4 hours. After the swelling is completed, add 12.5 g of anhydrous ferric chloride, raise the temperature to 40 °C and react for 60 hours. Finally, filter the mother liquor by suction, wash with water until neutral, and use the Volhard method to detect that the chlorine content is 18.6 wt%, dry at 60 °C, and detect that the water content is 2.5 wt% to obtain chloromethylated macroporous polystyrene resin beads.

[0034] In the examples of the present invention, other chlorine balls with effective chlorine content and water content can be prepared according to the above preparation method of chlorine balls by simply adjusting the reaction temperature, reaction time of chloromethylation or the dosage of anhydrous ferric chloride. This belongs to the conventional technology in this field and will not be elaborated here.

[0035] Example 1 A preparation method of an ion exchange resin for separating and recovering an extractant from a metal liquor recovered from a lithium battery includes the following steps: 1) Select chlorine balls with an effective chlorine content of 18.6 wt% and a water content of 2.5 wt%; 2) Add 100 g of chlorine balls, 500 mL of deionized water and 10 g of sulfamic 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 is completed, detect that the residual chlorine content of the obtained resin is 13.8 wt%, wash the obtained resin with deionized water until neutral, dropwise add 30 wt% sodium hydroxide solution to adjust the pH value to 12, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is denoted as PA resin; 3) Add the PA resin obtained in step 2) to 500 mL of diethylenetriamine solution, swell for 3 hours, raise the temperature to 80 °C, and react for 20 hours to obtain an aminated mother liquor containing resin; 4) Filter the aminated mother liquor containing resin by suction, add 400 mL of methanol to the obtained resin, raise the temperature to 50 °C, stir and wash for 4 hours, then filter the methanol washing solution by suction, and wash the obtained resin with deionized water until neutral. The obtained resin is denoted as PAS resin; 5) Add the PAS resin obtained in step 4) to ethanol for swelling. After swelling for 6 hours, add solid sodium hydroxide to adjust the pH value to 9.5. The specific dosage of sodium hydroxide is based on the pH value. Then add 30 g of n-octyl bromide, raise the temperature to 70 °C and react for 20 hours to obtain an ethanol mother liquor containing resin; 6) Filter the ethanol mother liquor containing resin by suction, wash successively with ethanol and deionized water, wash with water until neutral, and discharge. The obtained ion exchange resin is denoted as PASW resin.

[0036] Example 2 A method for preparing an ion exchange resin for separating and recovering an extractant from a metal liquor recovered from a lithium battery, comprising the following steps: 1) Select a chlorine ball with an effective chlorine content of 19.2 wt% and a water content of 2.2 wt%; 2) Add 100 g of chlorine balls, 500 mL of dimethyl sulfoxide and 6 g of p-aminobenzenesulfonic acid into 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 detected to be 14.9 wt%. Wash the obtained resin with deionized water until neutral, dropwise add 30 wt% sodium hydroxide solution, adjust the pH value to 11, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is denoted as PA resin; 3) Add the PA resin obtained in step 2) into 500 mL of tetraethylenepentamine solution, swell for 3 hours, raise the temperature to 110 °C, and react for 13 hours to obtain an aminated mother liquor containing the resin; 4) Filter the aminated mother liquor containing the resin by suction, add 400 mL of ethanol to the obtained resin, raise the temperature to 55 °C, stir and wash for 3 hours, then filter the ethanol washing liquid by suction. Wash the obtained resin with deionized water until neutral. The obtained resin is denoted as PAS resin; 5) Add the PAS resin obtained in step 4) into ethylene glycol for swelling. After swelling for 6 hours, add solid sodium hydroxide to adjust the pH value to 8. The specific dosage of sodium hydroxide is based on the pH value. Then add 30 g of n-decyl bromide, raise the temperature to 80 °C and react for 10 hours to obtain an ethylene glycol mother liquor containing the resin; 6) Filter the ethylene glycol mother liquor containing the resin by suction, and then wash it successively with ethylene glycol and deionized water. Wash with water until neutral, and discharge. The obtained ion exchange resin is denoted as PASW resin.

[0037] Example 3 A method for preparing an ion exchange resin for separating and recovering an extractant from a metal liquor recovered from a lithium battery, comprising the following steps: 1) Select a chlorine ball with an effective chlorine content of 18.6 wt% and a water content of 2.5 wt%; 2) Add 100 g of chlorine balls, 500 mL of ethyl acetate and 5 g of p-aminobenzoic acid into 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 detected to be 13.8 wt%. Wash the obtained resin with deionized water until neutral, dropwise add 20 wt% sodium hydroxide solution, adjust the pH value to 11.5, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is denoted as PA resin; 3) Add the PA resin obtained in step 2) into 500 mL of ethylenediamine solution, swell for 3 hours, raise the temperature to 100 °C, and react for 15 hours to obtain an aminated mother liquor containing the resin; 4) Filter the aminated mother liquor containing resin by suction, 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 by suction, and wash the obtained resin with deionized water until neutral. The obtained resin is denoted as PAS resin; 5) Add the PAS resin obtained in step 4) to dimethyl sulfoxide for swelling. After swelling for 6 hours, adjust the pH value to 9 by adding solid sodium hydroxide. The specific dosage of sodium hydroxide is based on the pH value. Then add 20 g of n-hexyl bromide, heat to 80 °C and react for 15 hours to obtain a dimethyl sulfoxide mother liquor containing resin; 6) Filter the dimethyl sulfoxide mother liquor containing resin by suction, then wash successively with dimethyl sulfoxide and deionized water, wash with water until neutral, and discharge. The obtained ion exchange resin is denoted as PASW resin.

[0038] Example 4 A method for preparing an ion exchange resin for separating and recovering an extractant from a metal feed liquid recovered from a lithium battery, comprising the following steps: 1) Select chlorine balls with an available chlorine content of 18.6 wt% and a water content of 2.5 wt%; 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 detected to be 13.5 wt%. Wash the obtained resin with deionized water until neutral, dropwise add 30 wt% sodium hydroxide solution to adjust the pH value to 11, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is denoted as PA resin; 3) Add the PA resin obtained in step 2) to 500 mL of triethylenetetramine solution, swell for 3 hours, heat to 120 °C, and react for 10 hours to obtain an aminated mother liquor containing resin; 4) Filter the aminated mother liquor containing resin by suction, 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 by suction, and wash the obtained resin with deionized water until neutral. The obtained resin is denoted as PAS resin; 5) Add the PAS resin obtained in step 4) to ethylene glycol for swelling. After swelling for 6 hours, adjust the pH value to 8 by adding solid sodium hydroxide. The specific dosage of sodium hydroxide is based on the pH value. Then add 45 g of n-decyl bromide, heat to 90 °C and react for 10 hours to obtain an ethylene glycol mother liquor containing resin; 6) Filter the ethylene glycol mother liquor containing resin by suction, then wash successively with ethylene glycol and deionized water, wash with water until neutral, and discharge. The obtained ion exchange resin is denoted as PASW resin.

[0039] Example 5 A method for preparing an ion exchange resin for separating and recovering an extractant from a metal liquor recovered from a lithium battery, comprising the following steps: 1) Select chlorinated beads with an available chlorine content of 18.8 wt% and a water content of 2.3 wt%; 2) Add 100 g of chlorinated beads, 500 mL of deionized water and 8 g of sulfamic acid into 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 detected to be 14.3 wt%. Wash the obtained resin with deionized water until it is neutral, dropwise add 30 wt% sodium hydroxide solution, adjust the pH value to 12, stabilize for 2 hours, and finally wash with water until it is neutral. The obtained resin is denoted as PA resin; 3) Add the PA resin obtained in step 2) into 500 mL of pentaethylenehexamine solution, swell for 3 hours, raise the temperature to 120 °C, and react for 12 hours to obtain an aminated mother liquor containing resin; 4) Filter the aminated mother liquor containing resin by suction, add 400 mL of methanol to the obtained resin, raise the temperature to 65 °C, stir and wash for 4 hours, then filter the methanol washing solution by suction. Wash the obtained resin with deionized water until it is neutral. The obtained resin is denoted as PAS resin; 5) Add the PAS resin obtained in step 4) into ethanol for swelling. After swelling for 6 hours, add solid sodium hydroxide to adjust the pH value to 9.5. The specific dosage of sodium hydroxide is based on the pH value. Then add 25 g of n-octyl bromide, raise the temperature to 75 °C and react for 13 hours to obtain an ethanol mother liquor containing resin; 6) Filter the ethanol mother liquor containing resin by suction, then wash it successively with ethanol and deionized water, wash with water until it is neutral, and discharge. The obtained ion exchange resin is denoted as PASW resin.

[0040] Example 6 A method for preparing an ion exchange resin for separating and recovering an extractant from a metal liquor recovered from a lithium battery, comprising the following steps: 1) Select chlorinated beads with an available chlorine content of 19.0% and a water content of 1.9%; 2) Add 100 g of chlorinated beads, 500 mL of ethyl acetate and 8 g of p-aminobenzoic acid into 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 detected to be 11 wt%. Wash the obtained resin with deionized water until it is neutral, dropwise add 20 wt% sodium hydroxide solution, adjust the pH value to 11.5, stabilize for 2 hours, and finally wash with water until it is neutral. The obtained resin is denoted as PA resin; 3) Add the PA resin obtained in step 2) into 500 mL of ethylenediamine solution, swell for 3 hours, raise the temperature to 90 °C, and react for 17 hours to obtain an aminated mother liquor containing resin; 4) Filter the aminated mother liquor containing resin by suction, add 400 mL of ethyl acetate to the obtained resin, heat up to 50 °C, stir and wash for 2 hours, then filter the ethyl acetate washing liquid by suction, and wash the obtained resin with deionized water until neutral. The obtained resin is denoted as PAS resin; 5) Add the PAS resin obtained in step 4) to dimethyl sulfoxide for swelling. After swelling for 6 hours, adjust the pH value to 9 by adding solid sodium hydroxide. The specific dosage of sodium hydroxide is based on the pH value. Then add 35 g of n-hexyl bromide, heat up to 85 °C and react for 17 hours to obtain a dimethyl sulfoxide mother liquor containing resin; 6) Filter the dimethyl sulfoxide mother liquor containing resin by suction, then wash it successively with dimethyl sulfoxide and deionized water, wash with water until neutral, and discharge. The obtained ion exchange resin is denoted as PASW resin.

[0041] Comparative Example 1 The preparation method of the resin in this comparative example includes the following steps: 1) Select chlorine balls with an available chlorine content of 18.6 wt% and a water content of 2.5 wt%; 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 detected to be 13.8 wt%. Wash the obtained resin with deionized water until neutral, dropwise add 30 wt% sodium hydroxide solution, adjust the pH value to 12, stabilize for 2 hours, and finally wash with water until neutral. The obtained resin is denoted as PA resin; 3) Add the PA resin obtained in step 2) to 500 mL of diethylenetriamine solution, swell for 3 hours, heat up to 80 °C, and react for 20 hours to obtain an aminated mother liquor containing resin; 4) Filter the aminated mother liquor containing resin by suction, add 400 mL of methanol to the obtained resin, heat up to 50 °C, stir and wash for 4 hours, then filter the methanol washing liquid by suction, and wash the obtained resin with deionized water until neutral. The obtained resin is denoted as PAS resin.

[0042] Comparative Example 2 The preparation method of the resin in this comparative example includes the following steps: 1) Select chlorine balls with an available chlorine content of 18.6 wt% and a water content of 2.5 wt%; 2) Add 100 g of chlorine balls and 500 mL of diethylenetriamine solution to a 1000 mL three-necked flask, swell for 3 hours, heat up to 80 °C, and react for 20 hours to obtain an aminated mother liquor containing resin; 3) Filter the aminated mother liquor containing resin by suction, add 400 mL of methanol to the obtained resin, heat up to 50 °C, stir and wash for 4 hours, then filter the methanol washing liquid by suction, and wash the obtained resin with deionized water until neutral. The obtained resin is denoted as PS resin; 4) Add the PS resin obtained in step 3) to ethanol for swelling. After swelling for 6 hours, add solid sodium hydroxide to adjust the pH value to 9.5. The specific dosage of sodium hydroxide is based on the pH value. Then add 30 g of n-octyl bromide, heat up to 70 °C and react for 20 hours to obtain an ethanol mother liquor containing the resin. 5) Filter the ethanol mother liquor containing the resin by suction, and then wash it successively with ethanol and deionized water until the water wash is neutral. Discharge the product to obtain the resin denoted as PSW resin.

[0043] Comparative Example 3 The preparation method of the resin in this comparative example includes the following steps: 1) Select chlorinated beads with an available chlorine content of 18.6 wt% and a water content of 2.5 wt%. 2) Add 100 g of chlorinated beads and 500 mL of diethylenetriamine solution to a 1000 mL three-necked flask, swell for 3 hours, heat up to 80 °C, and react for 20 hours to obtain an aminated mother liquor containing the resin. 3) Filter the aminated mother liquor containing the resin by suction, add 400 mL of methanol to the obtained resin, heat up to 50 °C, stir and wash for 4 hours, then filter the methanol washing solution by suction, and wash with deionized water until neutral to obtain the resin denoted as PS resin.

[0044] To verify the technical effects 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, on the basis of Example 1, Comparative Example 1 only carried out hydrophilic modification and did not carry out lipophilic modification; Comparative Example 2 only carried out lipophilic modification and did not carry out hydrophilic modification; while Comparative Example 3 neither carried out hydrophilic modification nor carried out lipophilic modification.

[0045] The performance indexes of the resins obtained in each example and comparative example of the present invention are shown in Table 1.

[0046]

[0047] From the performance indicators of Examples 1 to 6 in Table 1, it can be seen that, firstly, a hydrophilic reagent containing sulfonic acid groups and carboxyl groups was used to hydrophilically modify the macroporous polystyrene resin. On the one hand, by detecting the weak acid exchange capacity of the PA resin (greater than 1.0 mmol / g), it was proved that the hydrophilic reagent was successfully grafted onto the backbone structure of the PA resin. On the other hand, by detecting the residual chlorine content of the PA resin, it was also shown that the hydrophilic reagent reacted with the chloromethyl group, consuming part of the chloromethyl group, so that the prepared PA resin contained certain hydrophilic groups. Secondly, an amination reaction was carried out on the PA resin with an amination reagent. On the one hand, the hydrophilicity of the resin was further enhanced. By detecting the weak base exchange capacity of the PAS resin (greater than 5.5 mmol / g), it was shown that the amino group in the amination reagent reacted with the residual chloromethyl group, making the PAS resin carry certain hydrophilic groups. On the other hand, in the present invention, an amination reagent containing at least two or more amino groups was selected to ensure that while improving the hydrophilicity of the resin, some amino groups remained, preparing for the next step of lipophilic modification of the PAS resin. Finally, a lipophilic modification was carried out on the PAS resin with a halogenated long-chain alkane containing a long-chain alkane. The decrease in the weak base exchange capacity of the PASW resin proved that the amino group reacted with the halogenated long-chain alkane, consuming part of the amino group, so that the backbone structure of the ion exchange resin contained certain lipophilic groups. Compared with Example 1, in Comparative Example 2, the sulfonic acid group was not connected. Therefore, the weak base exchange capacity of its PS resin was higher than that of the PAS resin in Example 1, which also proved that during the synthesis of the resin in the present invention, an ion exchange resin containing hydrophilic groups was successfully prepared.

[0048] In order to further verify the removal effect of the ion exchange resin prepared by the present invention on the extractant in the metal feed liquid for lithium battery recycling, 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 nickel sulfate feed liquid (referred to as the original solution) containing an organophosphoric acid extractant prepared. In the present invention, bis(2,4,4-trimethylpentyl) phosphoric acid was selected as the organophosphoric acid extractant. Among them, the nickel sulfate feed liquid was green, with a pH value of 5 - 6, a nickel sulfate concentration of 105 g / L, and the extractant content was 100 mg / L.

[0049] The specific experimental method is as follows: 1) Pretreatment: Take 80 mL of the wet resin samples prepared in each example and each comparative example of the present invention, load them into a glass chromatography column, tamp them, and pretreat them with 10% sulfuric acid solution with a volume three times that of the resin, and then wash them with deionized water until the outlet pH value is neutral to obtain an ion exchange resin column for standby; 2) Column passing: Before the experiment, stir the nickel sulfate feed solution for 2 hours to mix it evenly, and then pass it through the ion exchange resin column at a flow rate of 1 BV / h (i.e., 80 mL / h). Take samples every 10 BV and detect the extractant content using an infrared oil analyzer (the results are shown in Table 2). A total of 100 BV is processed, and then stop column passing. After column passing is completed, mix all the effluent to obtain a 100 BV mixed sample, and detect the extractant content in the 100 BV mixed sample (the results are shown in Table 2); 3) Desorption: When 100 BV is processed, displace the feed solution in the ion exchange resin column with 1 BV of deionized water, and then use 4 BV of hot water at 80 - 90 °C to desorb the ion exchange resin column at a flow rate of 0.5 BV / h. Collect the desorbate. After the desorbate cools down, separate the extractant and water, and reserve the extractant to achieve the purpose of recovering the extractant.

[0050]

[0051] 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 feed solution, that is, the extractant in the nickel sulfate feed solution is reduced to less than 1 mg / L, and 100 BV can be stably treated, and 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 for efficiently removing and recovering the extractant. This is because after the macroporous polystyrene resin is modified with hydrophilic and lipophilic groups in the present invention, the internal structure of the macroporous polystyrene resin is changed, and the skeleton structure of the obtained ion exchange resin contains hydrophilic groups (such as sulfonic acid groups, carboxylic acid groups and amine groups). On the one hand, it can form hydrogen bond interactions with water molecules in the nickel sulfate feed solution, so that the nickel sulfate feed solution 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 nickel sulfate feed solution; on the other hand, introducing 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 feed solution, increase the surface activity, enhance the oil-water interfacial competitive separation ability, and change the properties of the oil-water interfacial film, so as to achieve the purpose of demulsification and separate the extractant from the nickel sulfate feed solution system; at the same time, the skeleton structure of the ion exchange resin contains lipophilic groups (such as long-chain alkanes), which can have hydrophobic interactions with the extractant in the nickel sulfate feed solution, quickly enrich the extractant in the nickel sulfate feed solution, so as to achieve the purpose of removing the extractant; and as more and more extractants are enriched on the skeleton structure of the ion exchange resin, the extractant molecular clusters will gradually become larger, and when it increases to a certain extent, oil droplets will be formed inside and on the surface of the ion exchange resin. When regenerated with hot water, the oil droplets dissolve in the hot water, thus realizing the regeneration of the ion exchange resin and the recovery of the extractant. In Comparative Example 1, only the macroporous polystyrene resin was hydrophilically modified, and the skeleton structure of the obtained ion exchange resin did not contain lipophilic groups of halogenated long-chain alkanes. The extractant in the nickel sulfate feed solution can enter the interior of the ion exchange resin, but the hydrophobic interaction between the extractant and the ion exchange resin is weak, and the separation effect on the extractant is poor, resulting in poor removal accuracy of the extractant and low adsorption capacity. In Comparative Example 2, only the macroporous polystyrene resin was lipophilically modified, which improved the hydrophobicity of the macroporous polystyrene resin, resulting in that the extractant in the nickel sulfate feed solution is difficult to enter the resin interior. However, since the skeleton structure of the resin contains a certain amount of amine groups, to a certain extent, it can also improve the hydrophilicity of the macroporous polystyrene resin. In the actual test process, it is specifically manifested that it has a certain removal effect on the extractant, high removal accuracy, but a small treatment multiple and is difficult to be used industrially. In Comparative Example 3, neither the hydrophilicity of the macroporous polystyrene resin was improved nor the hydrophobicity of the macroporous polystyrene resin was changed. The actual treatment effect is that the removal accuracy of the extractant is poor and the treatment multiple is also low.

[0052] In summary, according to the hydrophobic characteristics of the extractant in the metal liquor recovered from lithium batteries, the present invention successfully prepares an ion exchange resin capable of efficiently removing the extractant from the metal liquor recovered from lithium batteries. Through the comparative experiments of examples and comparative examples, it is verified that the ion exchange resin prepared by the present invention can achieve the removal of the extractant from the metal liquor recovered from lithium batteries and effectively recover the extractant. The ion exchange resin prepared by the method of the present invention is not only applicable to the removal and recovery of the extractant from the metal liquor recovered from lithium batteries, but also can effectively remove and resourcefully recover the extractant in the generated liquor during the wet extraction process of producing valuable metals such as lithium, nickel, cobalt, and manganese.

[0053] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the present invention.

Claims

1. A method for preparing an ion exchange resin, characterized in that, Comprising: S1. Mix and swell a chloromethylated macroporous polystyrene resin bead, a hydrophilic reagent and a solvent, then heat for reaction. After the reaction is completed, wash the obtained resin with water until neutral, adjust the pH value to 11 - 12, keep it stable for a preset time, and then wash with water until neutral. The obtained resin is denoted as PA resin; the hydrophilic reagent is one or more of sulfamic acid, p-aminobenzenesulfonic acid and p-aminobenzoic acid; S2. Mix and swell the PA resin with a solution of an amination reagent, then heat for reaction. After the reaction is completed, wash the obtained resin with a first organic solvent first, and then wash with water until neutral. The obtained resin is denoted as PAS resin; S3. Mix and swell the PAS resin with a second organic solvent, then adjust the pH value to 8 - 9.5, and then add a halogenated long-chain alkane with 6 - C 20 . Heat for reaction. After the reaction is completed, wash the resulting resin with the second organic solvent first, and then wash with water until neutral to obtain an ion exchange resin.

2. The preparation method of the ion exchange resin according to claim 1, characterized in that, In S1, the mass ratio of the hydrophilic reagent to the chloromethylated macroporous polystyrene resin bead is (0.03 - 0.1):

1.

3. The preparation method of the ion exchange resin according to claim 1, characterized in that, In S1, the reaction temperature is 40 - 50 °C, and the reaction time is 3 - 6 hours.

4. The preparation method of the ion exchange resin according to claim 1, characterized in that, In S2, the amination reagent is one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

5. The preparation method of the ion exchange resin according to claim 1, characterized in that In S2, the reaction temperature is 80 - 120 °C, and the reaction time is 10 - 20 hours.

6. The preparation method of the ion exchange resin according to claim 1, characterized in that, In S3, the halogenated long-chain alkane is n-octyl bromide, n-decyl bromide or n-hexyl bromide.

7. The preparation method of the 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 bead is (0.2 - 0.45):

1.

8. The preparation method of the ion exchange resin according to claim 1, characterized in that, In S3, the reaction temperature is 70 - 90 °C, and the reaction time is 10 - 20 hours.

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

10. Use of the ion exchange resin according to claim 9 in separating and recovering an extractant in a lithium battery recycling metal liquor.

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