Adsorbent particles, substrate particles, packed column, and method for recovering rare earth elements

Abstract

These absorbent particles include a carrier particle which comprises an organic polymer that includes monomer units derived from a styrene-base monomer, an organic compound which is attached to the surface of the carrier particle and which has an amino group, and a diglycolic acid residue which is bonded to the amino group. The organic compound further has at least one group selected from a carbonyl group, a sulfonyl group, a sulfinyl group, and an oxyalkylene group.

Description

[Technical Field]

[0001] The present disclosure relates to sorbent particles, substrate particles, packed columns, and methods for recovering rare earth elements. [Background technology]

[0002] As an adsorbent that selectively adsorbs and desorbs rare earth elements, adsorbents in which diglycolic acid is introduced onto the surfaces of various particles have been proposed (Patent Document 1, Non-Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6103611 [Non-patent literature]

[0004] [Non-Patent Document 1] Takeshi Ogata, Hydrometallurgy, 152 (2015) 178-182 [Non-patent document 2] Tomohiro Shinozaki, Ind. Eng.Chem. Res., 57 (2018) 11424-11430 Summary of the Invention [Problem to be solved by the invention]

[0005] One aspect of the present disclosure provides adsorbent particles with high rare earth element loading. [Means for solving the problem]

[0006] One aspect of the present disclosure relates to adsorbent particles comprising carrier particles containing an organic polymer containing monomer units derived from a styrene-based monomer, an organic compound having an amino group attached to the surface of the carrier particles, and a diglycolic acid residue bonded to the amino group, wherein the organic compound further has at least one group selected from the group consisting of a carbonyl group, a sulfonyl group, a sulfinyl group, and an oxyalkylene group.

[0007] Another aspect of the present disclosure relates to a base particle comprising a carrier particle containing an organic polymer including a monomer unit derived from a styrene-based monomer, and an organic compound having an amino group attached to the surface of the carrier particle, wherein the organic compound further has at least one group selected from the group consisting of a carbonyl group, a sulfonyl group, a sulfinyl group, and an oxyalkylene group.

[0008] Yet another aspect of the present disclosure relates to a packed column including a column body and the above-described adsorbent particles packed in the column body.

[0009] Yet another aspect of the present disclosure relates to a method for recovering rare earth elements, comprising: contacting the above-described adsorbent particles with a solution containing rare earth elements, thereby adsorbing the rare earth elements onto the adsorbent particles; and desorbing the rare earth elements from the adsorbent particles by contacting the particles with an acidic solution containing an acid. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, it is possible to provide adsorbent particles that can adsorb a large amount of rare earth elements. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing an example of a packed column. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention is not limited to the following examples.

[0013] An example of an adsorbent particle includes a carrier particle containing an organic polymer, an organic compound having an amino group attached to the surface of the carrier particle, and a diglycolic acid residue bonded to the amino group in the organic compound.

[0014] The carrier particles are polymer particles containing an organic polymer as a main component. The organic polymer may be crosslinked. The proportion of the organic polymer in the carrier particles may be 50 to 100 mass%, 60 to 100 mass%, 70 to 100 mass%, 80 to 100 mass%, or 90 to 100 mass% relative to the mass of the carrier particles.

[0015] The organic polymer forming the carrier particles may be a polymer containing a monomer unit derived from a styrene-based monomer (hereinafter, sometimes referred to as a "styrene-based polymer"). The styrene-based monomer is styrene or a styrene derivative, and may be a crosslinkable monomer, a monofunctional monomer, or a combination thereof, as described below. The proportion of the styrene-based monomer in the styrene-based polymer may be 20 to 85 mol % or 35 to 70 mol % based on the total amount of monomer units constituting the styrene-based polymer.

[0016] The organic polymer forming the carrier particles may be a polymer containing a crosslinkable monomer as a monomer unit. The crosslinkable monomer may be, for example, a divinyl compound such as divinylbenzene, divinylbiphenyl, divinylnaphthalene, or divinylphenanthrene. These crosslinkable monomers may be used alone or in combination of two or more. From the viewpoints of durability, acid resistance, and alkali resistance, the crosslinkable monomer may be divinylbenzene, which is a styrene-based monomer. The proportion of monomer units derived from the crosslinkable monomer in the organic polymer may be 1 to 80 mol%, 1 to 60 mol%, or 1 to 40 mol% relative to the total amount of monomer units constituting the organic polymer.

[0017] The organic polymer forming the carrier particles may be a copolymer of a crosslinkable monomer and a monofunctional monomer. Examples of monofunctional monomers include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, pt-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene. These may be used alone or in combination of two or more. From the viewpoint of acid resistance and alkali resistance, the monofunctional monomer may be styrene.

[0018] The organic polymer forming the carrier particles may contain, as a monomer unit, a monomer having a reactive group that reacts with the organic compound described below. The organic polymer may be a copolymer containing, as a monomer unit, a crosslinkable monomer and a monomer having a reactive group. The reactive group may be, for example, an epoxy group, a chloro group, or a combination thereof. An example of a monomer having an epoxy group is glycidyl methacrylate. An example of a monomer having a chloro group is 4-chloromethylstyrene. The proportion of monomer units derived from monomers having a reactive group in the organic polymer may be 15 to 80 mol %, or 30 to 65 mol %, based on the total amount of monomer units constituting the organic polymer.

[0019] The average particle size of the carrier particles may be 50 to 1000 μm, or 200 to 1000 μm. If the average particle size of the carrier particles is small, the pressure in the packed column filled with the adsorbent particles may increase. Here, the average particle size of the carrier particles can be determined by the following measurement method. 1) The particles are dispersed in water (containing a dispersant such as a surfactant) to prepare a dispersion containing 1% by mass of the particles. 2) Using a flow particle image analyzer, the average particle size is measured from images of approximately 10,000 particles in the dispersion.

[0020] The carrier particles may be porous polymer particles. In the case of porous polymer particles, the surface of the pores is also included in the "surface of the carrier particles." When the carrier particles are porous polymer particles, the specific surface area of ​​the carrier particles is 50 m 2 / g or more, and 2 / g or less. A larger specific surface area tends to allow a larger amount of substance to be adsorbed. The specific surface area here refers to the BET specific surface area determined by adsorption of nitrogen gas.

[0021] The organic compound attached to the surface of the carrier particle has at least one group selected from the group consisting of a carbonyl group, a sulfonyl group, a sulfinyl group, and an oxyalkylene group (hereinafter collectively referred to as a "hydrophilic group"), and an amino group. Some or all of the amino groups in the organic compound may form salts such as hydrochlorides and acetates. In this specification, the oxyalkylene group includes an oxyalkylene group contained in a group having a polyalkylene glycol chain. The group having a polyalkylene glycol chain may be a group having a polyethylene glycol chain.

[0022] The presence of the hydrophilic group in the organic compound, in combination with the interaction of the glycolic acid residue with the rare earth element, can contribute to further improving the adsorption amount of the rare earth element. The hydrophilic group may be a sulfonyl group. It is also required to suppress the adsorption amount of metals other than rare earth elements to the adsorbent particles. Examples of metals other than rare earth elements include iron. Adsorbent particles containing the organic compound having the hydrophilic group can increase the adsorption amount of rare earth elements while suppressing the adsorption of other metals such as iron.

[0023] An example of the organic compound attached to the surface of the carrier particles is a polymer having a main chain containing a constitutional unit represented by the following formula (1) and a constitutional unit represented by the following formula (2). [ka] In formula (1), R 1represents an alkylene group or a single bond, and R 2 represents an alkyl group or a hydrogen atom. [ka] In formula (2), X represents a carbonyl group, a sulfonyl group, a sulfinyl group, or an oxyalkylene group. The group represented by formula (2) may be a sulfonyl group represented by the following formula (2-1). [ka]

[0024] In formula (1), R 1 When R is an alkylene group, the number of carbon atoms in the alkylene group may be 1 or more or 2 or more. From the viewpoint of increasing the amount of rare earth elements adsorbed and further suppressing the amount of metals other than rare earth elements adsorbed, the number of carbon atoms in the alkylene group may be 4 or less, 3 or less, or 2 or less. 2 When is an alkyl group, the number of carbon atoms in the alkyl group may be 1 or more or 2 or more. From the viewpoint of increasing the amount of rare earth elements adsorbed and further suppressing the amount of metals other than rare earth elements adsorbed, the number of carbon atoms in the alkyl group may be 4 or less or 3 or less.

[0025] When the organic compound attached to the surface of the carrier particle is the above-mentioned polymer, the total content of the structural unit represented by formula (1) and the structural unit represented by formula (2) or formula (2-1) may be 20% by mass or more, 40% by mass or more, or 80% by mass or more, based on the total amount of structural units constituting the polymer, and may be 100% by mass or less, 80% by mass or less, or 40% by mass or less. In this specification, "the total amount of structural units constituting the polymer" may be substantially the same as the total mass of the polymer.

[0026] The organic compound attached to the surface of the carrier particle may be, for example, a polymer having a main chain containing a constitutional unit represented by the following formula (11): 1 and R 2 is R in the formula (1). 1 and R2 is synonymous with. [ka]

[0027] When the organic compound attached to the surface of the carrier particle is a polymer having a main chain containing a structural unit represented by formula (11), the content of the structural unit represented by formula (11) may be 20% by mass or more, 40% by mass or more, or 80% by mass or more, based on the total amount of structural units constituting the polymer, and may be 100% by mass or less, 80% by mass or less, or 40% by mass or less.

[0028] Another example of the organic compound attached to the surface of the carrier particle is a polymer having a main chain containing a constitutional unit represented by the following formula (3) and a constitutional unit represented by the above formula (2) or formula (2-1). The constitutional unit represented by formula (2) is as described above. [ka]

[0029] In formula (3), m and n each independently represent a positive integer. m in formula (3) may be 1 or more, 2 or more, or 3 or more, and may be 3 or less, or 2 or less. n in formula (3) may be 1 or more, 2 or more, or 3 or less, or 2 or less.

[0030] When the organic compound attached to the surface of the carrier particle is the above-mentioned polymer, the total content of the structural unit represented by formula (3) and the structural unit represented by formula (2) may be 20% by mass or more, 40% by mass or more, or 80% by mass or more, based on the total amount of structural units constituting the polymer, and may be 100% by mass or less, 80% by mass or less, or 40% by mass or less.

[0031] The organic compound attached to the surface of the carrier particle may be, for example, a polymer having a main chain containing a constituent unit represented by the following formula (12): The polymer having a main chain containing a constituent unit represented by formula (12) may be a copolymer of diallylamine and sulfur dioxide. [ka]

[0032] When the organic compound attached to the surface of the carrier particle is a polymer having a main chain containing a structural unit represented by formula (12), the content of the structural unit represented by formula (12) may be 20% by mass or more, 40% by mass or more, or 80% by mass or more, based on the total amount of structural units constituting the polymer, and may be 100% by mass or less, 80% by mass or less, or 40% by mass or less.

[0033] The above-mentioned polymer, which is an organic compound attached to the carrier particles, may further contain other structural units in addition to the structural unit represented by formula (1) and the structural unit represented by formula (2). When the polymer contains a structural unit represented by formula (11) or a structural unit represented by formula (12), the polymer may further contain other structural units in addition to the structural unit represented by formula (11) and the structural unit represented by formula (12).

[0034] When the organic compound attached to the surface of the carrier particles is one of the above-mentioned polymers, the molecular weight (weight average molecular weight) of the polymer may be 200 or more, or 250 or more. The molecular weight (weight average molecular weight) of the polymer may be 100,000 or less, 70,000 or less, 10,000 or less, or 7,000 or less. The molecular weight (weight average molecular weight) of the polymer may be 200 or more and 100,000 or less, 70,000 or less, 10,000 or less, or 7,000 or less, or 250 or more and 100,000 or less, 70,000 or less, 10,000 or less, or 7,000 or less. The weight average molecular weight is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC) using a calibration curve with standard polystyrene.

[0035] At least a portion of the organic compound (or polymer) attached to the surface of the carrier particle may be covalently bonded to the organic polymer forming the carrier particle. For example, if the organic polymer forming the carrier particle has a reactive group (e.g., an epoxy group), the organic compound can be covalently bonded to the organic polymer by reaction between the reactive group and an amino group.

[0036] The ratio of the amount of the organic compound to the mass of the carrier particles may be, for example, 5 to 50 mass %, or 10 to 40 mass %. The amount of amino groups in the adsorbent particles may be 0.1 to 100 mmol, 0.5 to 100 mmol, 0.1 to 20 mmol, or 0.5 to 20 mmol per 1 g of the adsorbent particles.

[0037] The amount of amino groups in the adsorbent particles or the substrate particles described below can be determined by measuring the amount of sulfuric acid consumed in the reaction with the amino groups by titration with sodium hydroxide. The method for measuring the amount of amino groups in the substrate particles includes the following steps. 1) Methanol is added to the base particles (A) g, and the resulting dispersion is heated at 75° C. for 30 minutes. 2) The base particles are collected from the dispersion by suction filtration onto a filter. While continuing suction, pure water is added to the base particles on the filter to replace the methanol with pure water, and then the base particles are conditioned using a small amount of 0.1 M aqueous sodium hydroxide solution. The base particles are then washed with pure water until the filtrate becomes neutral. 3) After washing, the base particles are transferred to a glass container using a small amount of pure water. The total amount of pure water in the container is adjusted to (B) g. 4) (C) g of 0.05 M sulfuric acid is added to the dispersion in the container, and then the dispersion in the container is stirred at room temperature for 30 minutes at 150 rpm. 5) (D) g of the supernatant of the dispersion is taken and purified water is added to adjust the liquid volume. 6) Titrate the diluted supernatant with 0.01 M aqueous sodium hydroxide solution and record the amount (E) mL of aqueous sodium hydroxide solution required for neutralization. 7) Calculate the amount of amino groups using the following formula: Amount of amino group (mmol / g) = [{0.1 × C × D / (B + C) - 0.01 × E} × (B + C) / D] / A

[0038] The diglycolic acid residue may be a monovalent group bonded to an amino group in an organic compound having a hydrophilic group (or a sulfonyl group) and an amino group, as represented by the following formula (21) or (22): The amino group in the formula is the amino group of the organic compound, and the portion excluding the amino group is the diglycolic acid residue. The diglycolic acid residue interacts with the rare earth complex, allowing the adsorbent particles to adsorb the rare earth element. [ka]

[0039] The adsorbent particles can be produced, for example, by a method including providing a substrate particle having no diglycolic acid residues, the substrate particle including a carrier particle and an organic compound described above attached to the surface of the carrier particle, and attaching diglycolic acid or an anhydride thereof to the organic compound to form the adsorbent particles. More specifically, diglycolic acid or an anhydride thereof can be attached to the amino group of the organic compound.

[0040] The base particles are prepared by attaching the above organic compound to the surface of the carrier particles. When the carrier particles contain an organic polymer having a reactive group, one example of a method for preparing the base particles includes: generating porous carrier particles by suspension polymerization in a reaction solution containing a monomer component including a monomer having a reactive group, a porosifying agent, and an aqueous medium; and bonding the organic compound to the organic polymer by the reaction between the reactive group and the above organic compound.

[0041] The porogen used to form porous particles is a component that promotes phase separation of particles during polymerization, thereby forming porous polymer particles. One example of a porogen is an organic solvent. Examples of organic solvents that can be used as porogens include aliphatic or aromatic hydrocarbons, esters, ketones, ethers, and alcohols. The porogen can include, for example, at least one solvent selected from the group consisting of toluene, xylene, cyclohexane, octane, butyl acetate, dibutyl phthalate, methyl ethyl ketone, dibutyl ether, 1-hexanol, 2-octanol, decanol, lauryl alcohol, and cyclohexanol.

[0042] The amount of the porosifying agent may be 0 to 300% by mass based on the total amount of the monomer components. The porosity of the porous polymer particles can be controlled by the amount of the porosifying agent. The size and shape of the pores in the porous polymer particles can be controlled by the type of porosifying agent.

[0043] The aqueous medium may contain water. This water may function as a porosifying agent. For example, adding an oil-soluble surfactant to the reaction solution forms particles containing the monomer and the oil-soluble surfactant, and these particles absorb water, which can promote phase separation within the particles. Removing one of the phases from the phase-separated particles makes the particles porous.

[0044] The aqueous medium contains water or a mixed solvent of water and a water-soluble solvent (e.g., a lower alcohol). The aqueous medium may contain a surfactant. The surfactant may be an anionic, cationic, nonionic, or zwitterionic surfactant.

[0045] The reaction solution for suspension polymerization may contain a polymerization initiator. Examples of the polymerization initiator include organic peroxides such as benzoyl peroxide, lauroyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, tert-butylperoxy-2-ethylhexanoate, and di-tert-butyl peroxide; and azo compounds such as 2,2'-azobisisobutyronitrile, 1,1'-azobiscyclohexanecarbonitrile, and 2,2'-azobis(2,4-dimethylvaleronitrile). The amount of the polymerization initiator may be 0.1 to 7.0 parts by mass per 100 parts by mass of the monomer components.

[0046] The reaction solution may contain a dispersion stabilizer to improve the dispersion stability of particles containing a monomer component. Examples of dispersion stabilizers include polyvinyl alcohol, polycarboxylic acid, celluloses (hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, etc.), and polyvinylpyrrolidone. These may be used in combination with an inorganic water-soluble polymer compound such as sodium tripolyphosphate. The dispersion stabilizer may be polyvinyl alcohol or polyvinylpyrrolidone. The amount of dispersion stabilizer may be 1 to 10 parts by mass per 100 parts by mass of the monomer.

[0047] The reaction liquid for suspension polymerization may contain a water-soluble polymerization inhibitor such as nitrites, sulfites, hydroquinones, ascorbic acids, water-soluble B vitamins, citric acid, and polyphenols.

[0048] The polymerization temperature for suspension polymerization can be appropriately selected depending on the types of monomer and polymerization initiator, and may be 25 to 110°C, or 50 to 100°C.

[0049] The resulting porous particles (support particles) may be washed and dried as needed, and then the amino groups of the organic compound may be reacted with the reactive groups of the organic polymer. This reaction may be carried out, for example, in a reaction solution containing the support particles, the organic compound, and a solvent, with heating as needed. The solvent is not particularly limited, but may be, for example, water.

[0050] After washing and drying the base particles as necessary, diglycolic acid or its anhydride is bonded to the amino groups of the organic compound attached to the carrier particles. This reaction can be carried out, for example, in a reaction solution containing the base particles, diglycolic acid or its anhydride, and a solvent, with heating as necessary. The solvent is not particularly limited, but may be, for example, tetrahydrofuran. This reaction forms adsorbent particles into which diglycolic acid residues have been introduced. The formed adsorbent particles are washed and dried as necessary.

[0051] Base particles containing carrier particles and organic compounds attached to the surfaces of the carrier particles may be used to obtain adsorbent particles or separation material particles having ligands other than diglycolic acid residues introduced therein. The average particle size of the base particles is usually substantially the same as that of the adsorbent particles.

[0052] Rare earth elements can be efficiently recovered by a method including contacting adsorbent particles with a solution containing rare earth elements, thereby adsorbing the rare earth elements onto the adsorbent particles, and desorbing the rare earth elements from the adsorbent particles by contacting them with an acidic solution containing an acid.

[0053] The temperatures of the adsorption solution and the acidic solution for desorption are not particularly limited, and may be, for example, 15 to 35° C. The contact time between the adsorption solution and the adsorbent particles may be, for example, 20 seconds or more, or 40 seconds or more, and may be 48 hours or less. The contact time between the desorption acidic solution and the adsorbent particles may be, for example, 5 seconds or more, or 10 seconds or more, and may be 6 hours or less.

[0054] The recovery method using the adsorbent particles according to this embodiment enables efficient recovery of rare earth elements based on the large adsorption capacity of the adsorbent particles. Furthermore, the adsorbent particles according to this embodiment have higher acid resistance than adsorbents containing silica particles as carrier particles, and are therefore advantageous in that they are less susceptible to deterioration during repeated use.

[0055] The pH of the solution used when adsorbing rare earth elements onto the adsorbent particles may be approximately 1.0 to 2.0. The acid concentration of the acidic solution for desorbing rare earth elements is adjusted to a strength sufficient to adequately desorb the rare earth elements. For example, the acid concentration of the acidic solution may be 2N or less, 1N or less, or 0.5N or less. The adsorbent particles according to this embodiment can desorb rare earth elements with high efficiency even when a relatively weak acidic solution is used. The use of a weak acidic solution is beneficial not only in terms of suppressing degradation of the adsorbent but also in terms of reducing environmental impact. The acidic solution may be, for example, hydrochloric acid.

[0056] The rare earth element to be recovered may be any of scandium, yttrium, and lanthanides, or may be a lanthanide such as dysprosium or neodymium. The solution containing the rare earth element to be recovered may be an aqueous solution. The rare earth element in the solution is usually dissolved in a solvent (e.g., water) as a cation.

[0057] Adsorbent particles may be used as a column packing material. FIG. 1 is a schematic diagram showing one embodiment of a packed column. The packed column 10 shown in FIG. 1 includes a column body 11 (column tube), a connection portion 12, and a column packing material 13 containing the adsorbent particles according to the embodiment described above. The connection portions 12 are disposed on both ends of the column body 11 to connect the column body 11 to a column chromatography device. The column packing material 13 is packed into the cylindrical column body 11. The materials of the column body 11 and the connection portions 12 are not particularly limited and may be stainless steel or a resin such as polyether ether ketone (PEEK).

[0058] The column packing material 13 containing the adsorbent particles is usually packed together with a solvent into the column body 11. The solvent is not particularly limited as long as it is a solvent in which the adsorbent particles can be dispersed, and may be, for example, water.

[0059] When rare earth elements are recovered using a packed column, for example, a solution containing rare earth elements is passed through the packed column, and then an acidic solution is passed through the packed column. [Example]

[0060] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to these examples.

[0061] 1. Preparation of Adsorbent Particles Example 1 base material particles Porous polymer particles composed of a styrene-based polymer, divinylbenzene-glycidyl methacrylate copolymer, were prepared as carrier particles. 1.0 g of these porous polymer particles was added to methanol, and the resulting suspension was agitated to wet the porous polymer particles with methanol. The suspension was then filtered while maintaining the wet state with purified water, and the methanol was replaced with purified water. Next, the purified water in the suspension was replaced with 12 g of an aqueous solution (20% by weight) of diallylamine hydrochloride sulfur dioxide copolymer (weight-average molecular weight 5000, "PAS-92," manufactured by Nittobo Medical Co., Ltd.), a compound (polymer) containing sulfonyl and amino groups, using the same method. 1.3 g of 50% by weight aqueous sodium hydroxide solution was then added. The resulting suspension was heated at 50°C for 3 hours to promote the reaction between the epoxy groups of the porous polymer particles and the diallylamine sulfur dioxide copolymer. The porous polymer particles were filtered, thoroughly washed with water, and then dried at 50°C for 15 hours to obtain base particles incorporating the diallylamine sulfur dioxide copolymer. The average particle size of the obtained base particles was 220 μm, and the amount of amino groups per 1 g of the base particles was 1.8 mmol.

[0062] Adsorbent particles 1.0 g of base particles and 4.7 g of diglycolic anhydride were reacted in tetrahydrofuran at 50°C for 8 hours. The particles were filtered and thoroughly washed with water, and then dried at 50°C for 15 hours to obtain adsorbent particles with diglycolic acid residues introduced therein.

[0063] Comparative Example 1 Porous polymer particles composed of the same divinylbenzene-glycidyl methacrylate copolymer as in Example 1 were prepared as carrier particles. These porous polymer particles were added to methanol, and the resulting suspension was agitated to wet the porous polymer particles with methanol. The suspension was then filtered while maintaining the wet state using pure water, thereby replacing the methanol with pure water. The pure water in the suspension was then replaced with ethylenediamine in the same manner. The suspension was heated at 50°C for 3 hours to promote the reaction between the epoxy groups of the porous polymer particles and ethylenediamine. The porous polymer particles collected by filtration were thoroughly washed with ethanol and water and then dried at 80°C for 15 hours to obtain base particles with ethylenediamine incorporated. The average particle size of the obtained base particles was 220 μm, and the amount of amino groups per 1 g of base particles was 2.0 mmol. Adsorbent particles with diglycolic acid residues incorporated were obtained by the same procedure as in Example 1, except that the obtained base particles were used.

[0064] <Liquid flow test> The adsorbent particles with diglycolic acid residues introduced therein obtained in the Examples and Comparative Examples were packed into a pressure-resistant column tube with an inner diameter of 5.0 mm to a carrier height of 50 mm (gel volume = 0.98 ml). Next, a sulfuric acid aqueous solution adjusted to pH = 1.5 was passed through the column at a flow rate of 1.64 mL / min for 5 minutes. Then, a sulfuric acid solution (also referred to as the original solution) with pH = 1.5 and containing 5 ppm dysprosium (Dy) and 1000 ppm Fe was passed through the column at a flow rate of 1.64 mL / min for 1 hour, and the liquid after passing through was collected as the effluent. The Dy and Fe concentrations of the effluent were measured using an ICP emission spectrometer, and the Dy adsorption rate and Fe adsorption rate were calculated using the following equations. Dy adsorption rate (%) = (Dy concentration of original solution (5 ppm) - Dy concentration of permeated solution) x 100 Fe adsorption rate (%) = (Fe concentration in the original solution (1000 ppm) - Fe concentration in the permeated solution) x 100

[0065] When the adsorbent particles of Example 1 were used, the Dy adsorption rate was 54% and the Fe adsorption rate was 3%, whereas when the adsorbent particles of Comparative Example 1 were used, the Dy adsorption rate was 11% and the Fe adsorption rate was 20%. Thus, it was confirmed that the adsorbent particles of the Example adsorb a sufficiently large amount of rare earth elements. The adsorption rate of the rare earth elements by the adsorbent particles of the Example was clearly higher than that by the adsorbent particles of the Comparative Example, and furthermore, it was found that the adsorption of Fe could be suppressed. [Explanation of symbols]

[0066] 10...packed column, 11...column body, 12...connection part, 13...column packing material.

Claims

1. Carrier particles containing an organic polymer including a monomer unit derived from a styrene-based monomer; an organic compound having an amino group attached to the surface of the carrier particle; a diglycolic acid residue bonded to the amino group, The adsorbent particles, wherein the organic compound is a polymer having a main chain containing a constitutional unit represented by the following formula (1) and a constitutional unit represented by the following formula (2): 【Chemistry 1】 [In formula (1), R 1 represents an alkylene group or a single bond, and R 2 represents an alkyl group or a hydrogen atom.] 【Chemistry 2】 [In formula (2), X represents a carbonyl group, a sulfonyl group, a sulfinyl group, or an oxyalkylene group.]

2. Carrier particles containing an organic polymer including a monomer unit derived from a styrene-based monomer; an organic compound having an amino group attached to the surface of the carrier particle; a diglycolic acid residue bonded to the amino group, The adsorbent particles, wherein the organic compound is a polymer having a main chain containing a constitutional unit represented by the following formula (3) and a constitutional unit represented by the following formula (2): 【Transformation 3】 [In formula (3), m and n each independently represent a positive integer.] 【Chemistry 4】 [In formula (2), X represents a carbonyl group, a sulfonyl group, a sulfinyl group, or an oxyalkylene group.] 3. The adsorbent particles of claim 1, wherein X is a sulfonyl group, a sulfinyl group, or an oxyalkylene group.

4. The adsorbent particles according to claim 1, wherein the organic compound is a polymer having a main chain containing a constitutional unit represented by the following formula (1) and a constitutional unit represented by the following formula (2-1): 【Transformation 5】 [In formula (1), R １ represents an alkylene group or a single bond, R ２ represents an alkyl group or a hydrogen atom. 【Transformation 6】

5. The adsorbent particles according to claim 4 , wherein the organic compound is a polymer having a main chain containing a constitutional unit represented by the following formula (11): 【Transformation 7】 [In formula (11), R １ and R ２ is R in the formula (1). １ and R ２ is equivalent to the above.]

6. The adsorbent particles according to claim 2, wherein the organic compound is a polymer having a main chain containing a constitutional unit represented by the following formula (3) and a constitutional unit represented by the following formula (2-1): 【Transformation 8】 [In formula (3), m and n each independently represent a positive integer.] 【Chemistry 9】

7. The adsorbent particles according to claim 6 , wherein the organic compound is a polymer having a main chain containing a constitutional unit represented by the following formula (12): 【Chemistry 10】

8. Adsorbent particles according to any one of claims 1 to 7, wherein the support particles are porous polymer particles.

9. The adsorbent particles according to any one of claims 1 to 8, which are used to recover rare earth elements.

10. Carrier particles containing an organic polymer including a monomer unit derived from a styrene-based monomer; an organic compound having an amino group attached to the surface of the carrier particle, The base particle, wherein the organic compound is a polymer having a main chain containing a constitutional unit represented by the following formula (1) and a constitutional unit represented by the following formula (2): 【Chemistry 11】 [In formula (1), R 1 represents an alkylene group or a single bond, and R 2 represents an alkyl group or a hydrogen atom.] 【Chemistry 12】 [In formula (2), X represents a carbonyl group, a sulfonyl group, a sulfinyl group, or an oxyalkylene group.]

11. Carrier particles containing an organic polymer including a monomer unit derived from a styrene-based monomer; an organic compound having an amino group attached to the surface of the carrier particle, The base particle, wherein the organic compound is a polymer having a main chain containing a constitutional unit represented by the following formula (3) and a constitutional unit represented by the following formula (2): 【Chemistry 13】 [In formula (3), m and n each independently represent a positive integer.] 【Chemistry 14】 [In formula (2), X represents a carbonyl group, a sulfonyl group, a sulfinyl group, or an oxyalkylene group.] 12. The base particle according to claim 10 or 11, wherein X is a sulfonyl group, a sulfinyl group, or an oxyalkylene group.

13. The base particle according to claim 10, wherein the organic compound is a polymer having a main chain containing a constitutional unit represented by the following formula (1) and a constitutional unit represented by the following formula (2-1): 【Chemistry 15】 [In formula (1), R １ represents an alkylene group or a single bond, R ２ represents an alkyl group or a hydrogen atom. 【Chemistry 16】

14. The base particle according to claim 13 , wherein the organic compound is a polymer having a main chain containing a structural unit represented by the following formula (11): 【Chemistry 17】 [In formula (11), R １ and R ２ is R in the formula (1). １ and R ２ is equivalent to the above.]

15. The base particle according to claim 11, wherein the organic compound is a polymer having a main chain containing a constitutional unit represented by the following formula (3) and a constitutional unit represented by the following formula (2-1): [Chemistry 18] [In formula (3), m and n each independently represent a positive integer.] 【Chemistry 19】

16. The base particle according to claim 15, wherein the organic compound is a polymer having a main chain containing a structural unit represented by the following formula (12): 【Chemistry 20】

17. 17. The substrate particle of any one of claims 10 to 16 used to form an adsorbent particle comprising diglycolic acid residues attached to said amino groups.

18. A packed column comprising a column body and the adsorbent particles according to any one of claims 1 to 9 packed in the column body.

19. contacting the adsorbent particles according to any one of claims 1 to 8 with a solution containing a rare earth element, thereby adsorbing the rare earth element onto the adsorbent particles; desorbing the rare earth elements from the sorbent particles by contact with an acidic solution comprising an acid.

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