JP2022059290A - Adsorbent particle, packed column, and method for recovering rare earth element - Google Patents

Abstract

To provide an adsorbent particle that can adsorb rare earth elements in large quantities.SOLUTION: An adsorbent particle has: a carrier particle that contains an organic polymer containing a styrenic monomer-derived monomer unit; an organic compound that is deposited on the surface of the carrier particle and has a functional group having a sulfur atom and an amino group; and a diglycolic acid residue bound to the amino group. In the adsorbent particles, the content of sulfur atoms is 0.5 mass% or more relative to the mass of the adsorbent particles.SELECTED DRAWING: None

Description

The present invention relates to a method for recovering adsorbent particles, a packed column, and a rare earth element.

As an adsorbent that selectively adsorbs and desorbs rare earth elements, those in which diglycolic acid is introduced on the surface of various particles have been proposed (Patent Document 1, Non-Patent Documents 1 and 2).

Japanese Patent No. 6103611

Takeshi Ogata, Hydrometallurgy, 152 (2015) 178-182 Tomohiro Shinozaki, Ind. Eng.Chem. Res., 57 (2018) 11424-11430

One aspect of the present invention provides adsorbent particles having a large adsorption amount of rare earth elements.

One aspect of the present invention is a carrier particle containing an organic polymer containing a monomer unit derived from a styrene-based monomer, an organic compound having a functional group containing a sulfur atom and an amino group attached to the surface of the carrier particle, and an organic compound having a functional group and an amino group. The present invention relates to adsorbent particles containing a diglycolic acid residue bonded to the amino group. The content of sulfur atoms in the adsorbent particles is 0.5% by mass or more based on the mass of the adsorbent particles.

Another aspect of the present invention relates to a packed column comprising a column body and the adsorbent particles packed in the column body.

Yet another aspect of the present invention is to contact the adsorbent particles with a solution containing a rare earth element, thereby adsorbing the rare earth element to the adsorbent particles and contacting the acid solution containing an acid. The present invention relates to a method for recovering a rare earth element, which comprises desorbing the rare earth element from the adsorbent particles.

According to one aspect of the present invention, it is possible to provide adsorbent particles having a large adsorption amount of rare earth elements.

It is a schematic diagram which shows one Embodiment of a filling column.

Hereinafter, some embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

The adsorbent particles according to one embodiment include carrier particles containing an organic polymer, an organic compound having a functional group containing a sulfur atom and an amino group attached to the surface of the carrier particles, and diglycolic acid bonded to an amino group. Includes residues.

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 50-100% by mass, 60-100% by mass, 70-100% by mass, 80-100% by mass, or 90-100% by mass.

The organic polymer forming the carrier particles according to one embodiment is a polymer containing a monomer unit derived from a styrene-based monomer (hereinafter, may be referred to as “styrene-based polymer”). The styrene-based monomer is styrene or a styrene derivative, and can be a crosslinkable monomer, a monofunctional monomer, or a combination thereof, which will be described later. The ratio of the styrene-based monomer to the styrene-based polymer may be 20 to 85 mol% or 35 to 70 mol% with respect to the total amount of the monomer units constituting the styrene-based polymer.

The organic polymer can 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, and divinylphenanthrene. These crosslinkable monomers may be used alone or in combination of two or more. From the viewpoint of durability, acid resistance, and alkali resistance, the crosslinkable monomer may be divinylbenzene, which is a styrene-based monomer. The proportion of the 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% with respect to the total amount of the monomer units constituting the organic polymer. ..

The organic polymer 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-. Dimethyl styrene, pn-butyl styrene, pt-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl Examples thereof include styrene-based monomers such as styrene, 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.

The organic polymer may contain a monomer having a reactive group that reacts with an organic compound described later as a monomer unit, or may be a copolymer containing a crosslinkable monomer and a monomer having a reactive group as a monomer unit. .. The reactive group may be, for example, an epoxy group, a chloro group or a combination thereof. Examples of monomers having an epoxy group include glycidyl methacrylate. Examples of monomers having a chloro group include 4-chloromethylstyrene. The proportion of the monomer unit derived from the monomer having a reactive group in the organic polymer may be 15 to 80 mol% or 30 to 65 mol% with respect to the total amount of the monomer units constituting the organic polymer.

The average particle size of the carrier particles may be 50 to 1000 μm, or 200 to 1000 μm. As the average particle size of the carrier particles decreases, the pressure of the packed column packed with the adsorbent particles may increase. Here, the average particle size of the carrier particles can be determined by the following measuring method.
1) The particles are dispersed in water (including a dispersant such as a surfactant) to prepare a dispersion liquid containing 1% by mass of the particles.
2) Using a flow-type particle image analyzer, measure the average particle size from images of about 10,000 particles in the dispersion.

The carrier particles may be porous polymer particles. In the case of porous polymer particles, the surface inside the porous material is also included in the "surface of the carrier particles". When the carrier particles are porous polymer particles, the specific surface area thereof may be 50 m ² / g or more, or 1000 m ² / g or less. The larger the specific surface area, the larger the amount of substance adsorbed tends to be. The specific surface area here means the BET specific surface area due to the adsorption of nitrogen gas.

The organic compound according to this embodiment has a functional group containing a sulfur atom. It is considered that the adsorption amount of the rare earth element is further improved by the functional group containing the sulfur atom of the organic compound in the adsorbent particles interacting with the rare earth element. Examples of functional groups containing a sulfur atom include a sulfonyl group (-S (= O) _2- ) and a sulfinyl group (-S (= O)-).

By introducing an organic compound having a functional group containing a sulfur atom, adsorbent particles containing a sulfur atom are formed. In particular, the content of sulfur atoms in the adsorbent particles may be 0.5% by mass or more or 20% by mass or less based on the mass of the adsorbent particles. When the content of sulfur atoms is large, the effect of improving the adsorption amount of rare earth elements tends to be greater. When the content of sulfur atoms is small, the adsorbent particles tend to be difficult to swell. Adsorbent particles that are difficult to swell can be filled in the column more efficiently. From the same viewpoint, the content of sulfur atom is 1.0% by mass or more, 2.0% by mass or more, 3.0% by mass or more, or 3.5% by mass or more based on the mass of the adsorbent particles. 20% by mass or less, 19% by mass or less, 18% by mass or less, 17% by mass or less, 16% by mass or less, 15% by mass or less, 14% by mass or less, 13% by mass or less, 12% by mass or less, 11 Mass% or less, 10 mass% or less, 9.0 mass% or less, 8.0 mass% or less, 7.0 mass% or less, 6.0 mass% or less, 5.0 mass% or less, or 4.0 mass% or less It may be as follows. Here, the content of sulfur atoms in the adsorbent particles can be a value measured by analysis of the adsorbent particles by combustion ion chromatography.

The organic compound further has an amino group. Some or all of the amino groups in the organic compound may form salts such as hydrochlorides and acetates. The organic compound has a glycolic acid residue bonded to the amino group. By combining an amino group and a functional group containing a sulfur atom, it is possible to obtain adsorbent particles having an even larger amount of adsorbed rare earth elements. Further, in the adsorbent particles, iron and the like can be mentioned as an example of the metal other than the rare earth element, which is also required to suppress the adsorption amount of the metal other than the rare earth element. The adsorbent particles according to the present embodiment contain an organic compound having an amino group and a functional group containing a sulfur atom, thereby increasing the adsorption amount of rare earth elements and suppressing the adsorption of other metals such as iron. You can also do it.

The content of nitrogen atoms in the adsorbent particles may be 0.2% by mass or more based on the mass of the adsorbent particles. When the content of nitrogen atom is large, the adsorption amount of rare earth elements tends to be further improved. From the same viewpoint, the nitrogen atom content is 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, or 2.0% by mass or more, based on the mass of the adsorbent particles. It may be 2.3% by mass or more. The upper limit of the content of the nitrogen atom is not particularly limited, but the content of the nitrogen atom is, for example, 8.0% by mass or less, 7.0% by mass or less, and 6.0% by mass or less based on the mass of the adsorbent particles. , 5.0% by mass or less, 4.0% by mass or less, or 3.0% by mass or less. Here, the content of the sulfur atom in the adsorbent particles can be a value measured by elemental analysis by the combustion method of the adsorbent particles.

式（１）中、Ｒ^１はアルキレン基又は単結合を表し、Ｒ^２はアルキル基又は水素原子を表す。

In one embodiment, the organic compound having a functional group containing a sulfur atom and an amino group has a main chain containing a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2). It may be a polymer.

In formula (1), R ¹ represents an alkylene group or a single bond, and R ² represents an alkyl group or a hydrogen atom.

In the formula (1), when R ¹ is an alkylene group, the carbon number of the alkylene group may be 1 or more or 2 or more, the adsorption amount of the rare earth element is made larger, and the adsorption amount of the metal other than the rare earth element is increased. From the viewpoint of further suppressing the above, it may be 4 or less, 3 or less, or 2 or less. When R ² is an alkyl group, the number of carbon atoms of the alkyl group may be 1 or more or 2 or more, from the viewpoint of increasing the adsorption amount of rare earth elements and further suppressing the adsorption amount of metals other than rare earth elements. May be 4 or less or 3 or less.

When the organic compound is the above polymer, the total content of the constituent units represented by the formula (1) and the constituent units represented by the formula (2) is based on the total mass of the constituent units constituting the polymer. It may be 20% by mass or more, 40% by mass or more, or 80% by mass or more, and may be 100% by mass or less, 80% by mass or less, or 40% by mass or less.

式（１１）中、Ｒ^１及びＲ^２は、前記式（１）におけるＲ^１及びＲ^２と同義である。 Such an organic compound may be, for example, a polymer having a main chain containing a structural unit represented by the following formula (11).

In the formula (11), R ¹ and R ² are synonymous with R ¹ and R ² in the formula (1).

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

式（３）中、ｍ及びｎはそれぞれ独立に正の整数を表す。 In another embodiment, the organic compound may be a polymer having a main chain containing a structural unit represented by the following formula (3) and a structural unit represented by the above-mentioned formula (2). The mode of the structural unit represented by the formula (2) is as described above.

In equation (3), m and n each independently represent a positive integer.

M in the 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 the formula (3) may be 1 or more, 2 or more, or 3 or more, and may be 3 or less or 2 or less.

When the organic compound is the above polymer, the total content of the constituent units represented by the formula (3) and the constituent units represented by the formula (2) is based on the total mass of the constituent units constituting the polymer. It may be 20% by mass or more, 40% by mass or more, or 80% by mass or more, and may be 100% by mass or less, 80% by mass or less, or 40% by mass or less.

Such an organic compound may be, for example, a polymer having a main chain containing a structural unit represented by the following formula (12). The polymer having a main chain containing the structural unit represented by the formula (12) may be a copolymer of diallylamine and sulfur dioxide.

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

The polymer described above may further contain a structural unit represented by the formula (1) and a structural unit other than the structural unit represented by the formula (2). When the polymer contains a structural unit represented by the formula (11) or the polymer contains a structural unit represented by the formula (12), the polymer is represented by the structural unit represented by the formula (11) and the polymer is represented by the formula (12). It may further include other structural units other than the constituent units to be formed.

When the organic compound having a functional group containing a sulfur atom is a polymer, 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 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, and 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 using a calibration curve of standard polystyrene by gel permeation chromatography (GPC).

At least a part of the organic compound (or polymer) adhering to the surface of the carrier particles may be bonded by a covalent bond with the organic polymer as the carrier particles. For example, when the organic polymer has a reactive group (for example, an epoxy group), the reaction between the reactive group and the amino group allows the organic compound to be covalently bonded to the organic polymer.

The ratio of the amount of the organic compound to the mass of the carrier particles may be, for example, 5 to 50% by mass, or 10 to 40% by 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.

The amount of amino groups in the adsorbent particles or the substrate particles described below can be determined by a method of measuring the amount of sulfuric acid consumed by the reaction with the amino groups by titration using sodium hydroxide. The method for measuring the amount of amino groups in the substrate particles includes the following operations.
1) Methanol is added to the base particle (A) g, and the obtained dispersion is heated at 75 ° C. for 30 minutes.
2) From the dispersion liquid, the substrate particles are collected on the filter by suction filtration. Methanol is replaced with pure water by adding pure water to the substrate particles on the filter while continuing suction, and then the substrate particles are conditioned with a small amount of 0.1 M aqueous sodium hydroxide solution. Then, the substrate particles are washed with pure water until the filtrate becomes neutral.
3) Transfer the washed substrate particles to a glass container using a small amount of pure water. Adjust so that the total amount of pure water in the container is (B) g.
4) Add (C) g of 0.05 M sulfuric acid to the dispersion in the container, and then stir the dispersion in the container at room temperature for 30 minutes at 150 rpm.
5) Take (D) g of the supernatant of the dispersion liquid and add pure water to it to adjust the liquid volume.
6) The diluted supernatant is titrated with a 0.01 M aqueous sodium hydroxide solution, and the amount (E) mL of the aqueous sodium hydroxide solution required for neutralization is recorded.
7) The amount of amino group is calculated by the following formula.
Amino group amount (mmol / g) = [{0.1 × C × D / (B + C) -0.01 × E} × (B + C) / D] / A

The diglycolic acid residue is a monovalent group bonded to an amino group in an organic compound having a functional group containing a sulfur atom and an amino group, for example, as represented by the following formula (21) or (22). May be good. The amino group in the formula is an amino group of an organic compound, and the portion excluding the amino group is a diglycolic acid residue. The diglycolic acid residue interacts with the rare earth complex so that the adsorbent particles can adsorb the rare earth element.

As the adsorbent particles, for example, a base particle having no diglycolic acid residue containing the carrier particles and the above-mentioned organic compound adhering to the surface of the carrier particles is prepared, and diglycolic acid or its own is added to the organic compound. It can be produced by a method comprising binding anhydrate and thereby forming adsorbent particles. More specifically, diglycolic acid or an acid anhydride thereof can be bonded to the amino group of the organic compound.

The base particle is produced by adhering the above organic compound to the surface of the carrier particle. An example of a method for preparing base material particles when the carrier particles contain an organic polymer having a reactive group is in a reaction solution containing a monomer component containing a monomer having a reactive group, a porosifying agent, and an aqueous medium. The suspension polymerization in the above comprises producing carrier particles which are porous particles, and the reaction of the reactive group with the above-mentioned organic compound to bond the organic compound with the organic polymer.

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

The amount of the porosifying agent may be 0 to 300% by mass with respect to the total amount of the monomer components. The porosity of the porous polymer particles can be controlled by the amount of the porosity agent. The size and shape of the pores of the porous polymer particles can be controlled by the type of the porosifying agent.

The aqueous medium may contain water. This water may function as a porosifying agent. For example, when an oil-soluble surfactant is added to the reaction solution, particles containing the monomer and the oil-soluble surfactant are formed, and the particles can absorb water to promote phase separation in the particles. By removing one phase from the phase-separated particles, the particles are made porous.

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

The reaction solution for suspension polymerization may contain a polymerization initiator. Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, benzoyl orthochloroperoxide, benzoyl orthomethoxy peroxide, 3,5,5-trimethylhexanoyl peroxide, and tert-butylperoxy-2-ethylhexano. Organic peroxides such as ate, di-tert-butyl peroxide; 2,2'-azobisisobutyronitrile, 1,1'-azobiscyclohexanecarbonitrile, 2,2'-azobis (2,4-azobis) Examples thereof include azo compounds such as dimethylvaleronitrile). The amount of the polymerization initiator may be 0.1 to 7.0 parts by mass with respect to 100 parts by mass of the monomer component.

In order to improve the dispersion stability of the particles containing the monomer component, the reaction solution may contain a dispersion stabilizer. Examples of the dispersion stabilizer 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 the dispersion stabilizer may be 1 to 10 parts by mass with respect to 100 parts by mass of the monomer.

The reaction solution for suspension polymerization may contain a water-soluble polymerization inhibitor such as nitrites, sulfites, hydroquinones, ascorbic acids, water-soluble vitamin Bs, citric acid, and polyphenols.

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

The generated porous particles (carrier particles) may be washed and dried if necessary, and then the reactive group such as the amino group of the organic compound may be reacted with the reactive group of the organic polymer. This reaction can be carried out, for example, in a reaction solution containing carrier particles, an organic compound and a solvent while heating, if necessary. The solvent is not particularly limited, but may be, for example, water.

After washing and drying the base particles as necessary, diglycolic acid or its anhydride is bonded to a reactive group such as an amino group in the organic compound attached to the carrier particles. This reaction can be carried out, for example, in a reaction solution containing base particles, diglycolic acid or an anhydride thereof, and a solvent while heating, if 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 if necessary.

Substrate particles containing the carrier particles and the organic compound adhering to the surface of the carrier particles may be used to obtain adsorbent particles or separator particles into which a ligand other than the diglycolic acid residue has been introduced. The average particle size of the substrate particles is usually substantially the same as the average particle size of the adsorbent particles.

The adsorbent particles are brought into contact with a solution containing a rare earth element to adsorb the rare earth elements to the adsorbent particles, and the adsorbent particles are desorbed from the adsorbent particles by contact with an acidic solution containing an acid. Rare earth elements can be efficiently recovered by a method including.

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

The recovery method using the adsorbent particles according to the present embodiment enables efficient recovery of rare earth elements based on a large amount of adsorption by the adsorbent particles. Further, since the adsorbent particles according to the present embodiment have high resistance to acid as compared with the adsorbent containing silica particles as carrier particles, they are also advantageous in that they are less deteriorated when used repeatedly.

The pH of the solution when the rare earth element is adsorbed on the adsorbent particles may be about 1.0 to 2.0. The acid concentration of the acidic solution for desorbing the rare earth element is adjusted to such a strength that the rare earth element is appropriately desorbed. For example, the acid concentration of the acidic solution may be 2 or less, 1 or less, or 0.5 or less. The adsorbent particles according to the present embodiment can desorb rare earth elements with high efficiency even when a relatively weak acidic acidic solution is used. The use of a weakly acidic acidic solution is beneficial not only in suppressing deterioration of the adsorbent but also in reducing the environmental load. The acidic solution may be, for example, hydrochloric acid.

The recovered rare earth element may be any of scandium, yttrium, and lanthanoid, and may be lanthanoid such as dysprosium and neodymium. The solution containing the recovered rare earth element may be an aqueous solution. Rare earth elements in solution are usually dissolved in a solvent (eg, water) as cations.

Adsorbent particles may be used as a column filler. FIG. 1 is a schematic diagram showing an embodiment of a packed column. The packed column 10 shown in FIG. 1 includes a column main body portion 11 (column tube), a connecting portion 12, and a column packing material 13 containing adsorbent particles according to the above-described embodiment. The connection unit 12 is arranged at both ends of the column body unit 11 in order to connect the column body unit 11 to the column chromatography device. The column filler 13 is filled in the tubular column main body 11. The material of the column main body 11 and the connecting portion 12 is not particularly limited, and may be stainless steel or a resin such as polyetheretherketone (PEEK).

The column packing material 13 containing the adsorbent particles is usually filled in the column body 11 together with the solvent. The solvent is not particularly limited as long as it is a solvent in which the adsorbent particles are dispersed, but may be, for example, water.

When recovering a rare earth element using a packed column, for example, a solution containing the rare earth element is passed through the packed column, and then an acidic solution is passed through the packed column.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

1. 1. Preparation of Adsorbent Particles <Example 1>
[Base particles]
Porous polymer particles made of divinylbenzene-glycidyl methacrylate copolymer, which is a styrene-based polymer, were prepared as carrier particles. 1.0 g of the porous polymer particles were added to methanol, and the suspension was shaken and stirred to wet the porous polymer particles with methanol. Then, the suspension was filtered with pure water while maintaining a wet state to replace methanol with pure water. Subsequently, the pure water of the suspension is subjected to the same method as that of a diallylamine hydrochloride sulfur dioxide copolymer (, weight average molecular weight 5000, "PAS-92"), which is a compound (polymer) having a sulfonyl group and an amino group. It was replaced with 12 g of an aqueous solution (concentration: 20% by mass) of Nittobo Medical Co., Ltd., and 1.3 g of a 50% by mass sodium hydroxide aqueous solution was further added. By heating the obtained suspension at 50 ° C. for 3 hours, the reaction between the epoxy group of the porous polymer particles and the diallylamine sulfur dioxide copolymer was allowed to proceed. The porous polymer particles taken out by filtration were thoroughly washed with water and then dried at 50 ° C. for 15 hours to obtain base particles into which a diallylamine sulfur dioxide copolymer was introduced. 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.

[Adsorbent particles]
1.0 g of the base particle and 4.7 g of the diglycolic acid anhydride were reacted in tetrahydrofuran at 50 ° C. for 8 hours. The particles taken out by filtration were thoroughly washed with water and then dried at 50 ° C. for 15 hours to obtain adsorbent particles into which diglycolic acid residues were introduced.

<Example 2>
Implemented except that 12 g of an aqueous solution of diallylamine hydrochloride sulfur dioxide copolymer (concentration 20% by mass) was changed to a mixed solution of 12 g of an aqueous solution of diallylamine hydrochloride sulfur dioxide copolymer (concentration 20% by mass) and 12 g of pure water. Substrate particles were obtained in the same manner as in Example 1. 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. Adsorbent particles into which a diglycolic acid residue was introduced were obtained by the same operation as in Example 1 except that the obtained base particles were used.

<Example 3>
The same as in Example 1 except that the 12 g of the aqueous solution of the diallylamine hydrochloride sulfur dioxide copolymer (concentration 20% by mass) was changed to 12 g of the aqueous solution of the diallylamine hydrochloride sulfur dioxide copolymer (concentration 30% by mass). Substrate particles were obtained. 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 2.1 mmol. Adsorbent particles into which a diglycolic acid residue was introduced were obtained by the same operation as in Example 1 except that the obtained base particles were used.

<Comparative Example 1>
Porous polymer particles made of the same divinylbenzene-glycidyl methacrylate copolymer as in Example 1 were prepared as carrier particles. The porous polymer particles were added to methanol, and the suspension was shaken and stirred to wet the porous polymer particles with methanol. Then, the suspension was filtered with pure water while maintaining a wet state to replace methanol with pure water. Subsequently, the pure water of the suspension was replaced with ethylenediamine in the same manner. By heating the suspension at 50 ° C. for 3 hours, the reaction between the epoxy group of the porous polymer particles and ethylenediamine was allowed to proceed. The porous polymer particles taken out by filtration were thoroughly washed with ethanol and water, and then dried at 80 ° C. for 15 hours to obtain base particles into which ethylenediamine was introduced. 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 2.0 mmol. Adsorbent particles into which a diglycolic acid residue was introduced were obtained by the same operation as in Example 1 except that the obtained base particles were used.

<Quantitative analysis>
The adsorbent particles obtained in Examples 1 to 3 or Comparative Example 1 were analyzed by combustion ion chromatography to quantify the sulfur atom content (S content) based on the mass of the adsorbent particles. In addition, the nitrogen content (N content) based on the mass of the adsorbent particles was quantified by elemental analysis by the combustion method of the adsorbent particles. The results are shown in Table 1.

<Liquid flow test>
The adsorbent particles into which the diglycolic acid residue was introduced, which were obtained in Examples and Comparative Examples, were filled in a pressure resistant column tube having an inner diameter of 5.0 mm so that the carrier height was 50 mm (gel volume = 0.98 ml). ). Next, a sulfuric acid aqueous solution adjusted to pH = 1.5 was passed through at a flow rate of 1.64 mL / min for 5 minutes. Then, a sulfuric acid solution containing 5 ppm of dysprosium (Dy) and 1000 ppm of Fe (also referred to as the original solution) at pH = 1.5 was passed at a flow rate of 1.64 mL / min for 1 hour, and the liquid after passing was recovered. Then, it was used as a passing solution. The concentration of Dy and the concentration of Fe in the passing liquid were measured using an ICP emission spectrometer, and the Dy adsorption rate and the Fe adsorption rate were calculated using the following formulas.
Dy adsorption rate (%) = (Dy concentration of the original solution (5 ppm) -Dy concentration of the passing liquid) × 100
Fe adsorption rate (%) = (Fe concentration of the original solution (1000 ppm) -Fe concentration of the passing liquid) × 100

As shown in Table 1, when the adsorbent particles of Examples 1 to 3 were used, the Dy adsorption rate was 38% or more and the Fe adsorption rate was 11.3% or less, whereas Comparative Example 1 was used. When the adsorbent particles of No. 1 were used, the Dy adsorption rate was 11% and the Fe adsorption rate was 20%. As described above, it was confirmed that the adsorbent particles of the examples adsorb rare earth elements with a sufficiently large adsorption amount. Further, it can be seen that the adsorption rate of the rare earth element by the adsorbent particles of the example is clearly larger than the adsorption rate of the rare earth element by the adsorbent particles of the comparative example, and further, the adsorption of Fe can be suppressed.

10 ... Filling column, 11 ... Column body, 12 ... Connection, 13 ... Column packing material.

Claims (8)

Carrier particles containing an organic polymer containing a monomer unit derived from a styrene-based monomer, and
An organic compound having a functional group containing a sulfur atom and an amino group attached to the surface of the carrier particles,
Adsorbent particles containing a diglycolic acid residue bonded to the amino group.
Adsorbent particles having a sulfur atom content in the adsorbent particles of 0.5% by mass or more based on the mass of the adsorbent particles. The adsorbent particle according to claim 1, wherein the content of the sulfur atom in the adsorbent particle is 20% by mass or less based on the mass of the adsorbent particle. The adsorbent particle according to claim 1 or 2, wherein the functional group containing a sulfur atom is at least one of a sulfonyl group and a sulfinyl group. The adsorbent particle according to any one of claims 1 to 3, wherein the content of nitrogen atom in the adsorbent particle is 0.2% by mass or more based on the mass of the adsorbent particle. The adsorbent particle according to any one of claims 1 to 4, wherein the carrier particles are porous polymer particles. The adsorbent particle according to any one of claims 1 to 5, which is used for recovering a rare earth element. A packed column comprising a column main body portion and the adsorbent particles according to any one of claims 1 to 6 filled in the column main body portion. The adsorbent particles according to any one of claims 1 to 5 are brought into contact with a solution containing a rare earth element, whereby the rare earth element is adsorbed on the adsorbent particles.
A method for recovering a rare earth element, which comprises desorbing the rare earth element from the adsorbent particles by contact with an acidic solution containing an acid.

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