阅读说明：本技术 吸附材料粒子、制造吸附材料粒子的方法、基材粒子、填充柱及回收稀土元素的方法 (Adsorbent particle, method for producing adsorbent particle, substrate particle, packed column, and method for recovering rare earth element ) 是由 青岛真裕 石川洋平 渡边优 于 2020-02-25 设计创作，主要内容包括：本发明公开了一种吸附材料粒子,其包含：载体粒子,含有有机聚合物；含氨基聚合物,附着于载体粒子的表面,并包含具有氨基的结构单元；及二甘醇酸残基,与含氨基聚合物的氨基键合。(The present invention discloses an adsorbing material particle, comprising: carrier particles comprising an organic polymer; an amino group-containing polymer attached to the surface of the carrier particle and comprising a structural unit having an amino group; and diglycolic acid residues bonded to amino groups of the amino-containing polymer.)

1. An adsorbent material particle comprising:

carrier particles comprising an organic polymer;

an amino-containing polymer attached to the surface of the carrier particle and comprising a structural unit having an amino group; and

a diglycolic acid residue bonded to an amino group of the amino group-containing polymer.

2. The adsorbent material particle of claim 1,

the organic polymer is a polymer comprising monomer units derived from a styrenic monomer.

3. The adsorbent material particle according to claim 1 or 2,

the support particles are porous polymer particles.

4. The adsorbent material particle according to any one of claims 1 to 3,

the amount of amino groups in the adsorbent particles is 0.1 to 100mmol per 1g of the adsorbent particles.

5. The adsorbent material particle according to any one of claims 1 to 4, for use in recovering rare earth elements.

6. A method of making adsorbent material particles, comprising:

preparing substrate particles comprising carrier particles containing an organic polymer and an amino group-containing polymer attached to the surface of the carrier particles and having an amino group; and

diglycolic acid or an anhydride thereof is bonded to the amino group of the amino group-containing polymer, thereby forming adsorbent material particles.

7. The method of claim 6, wherein,

the organic polymer comprises structural units having reactive groups,

the substrate particles are prepared by a method comprising: bonding the amino-containing polymer to the organic polymer by reaction of the reactive group with the amino-containing polymer.

8. A substrate particle, comprising:

carrier particles comprising an organic polymer; and

an amino group-containing polymer attached to the surface of the carrier particle and comprising a structural unit having an amino group.

9. The substrate particle according to claim 8,

the organic polymer is a polymer comprising monomer units derived from a styrenic monomer.

10. The substrate particle according to claim 8 or 9,

the support particles are porous polymer particles.

11. The substrate particle of any one of claims 8 to 10,

the amount of amino groups in the base particles is 0.1 to 100mmol per 1g of the base particles.

12. The substrate particle according to any one of claims 8 to 11, for forming an adsorbent material particle comprising diglycolic acid residues bonded to amino groups of the amino-containing polymer.

13. A packed column comprising a column tube and the adsorbent particles according to any one of claims 1 to 5 packed in the column tube.

14. A method of recovering rare earth elements, comprising:

contacting the adsorbent material particles of any one of claims 1 to 5 with a solution comprising a rare earth element, thereby adsorbing the rare earth element to the adsorbent material particles; and

the rare earth element is desorbed from the adsorbent particles by contact with an acidic solution containing an acid.

15. The method of claim 14, wherein

The acid concentration of the acidic solution is less than 0.5 gram equivalent/L.

Technical Field

The present invention relates to an adsorbent particle, a method for producing an adsorbent particle, a base material particle, a packed column, and a method for recovering a rare earth element.

Background

As an adsorbent that selectively adsorbs and desorbs a rare earth element, an adsorbent in which diglycolic acid is introduced onto the surface of various particles has been proposed (patent document 1, non-patent documents 1 and 2).

Prior art documents

Patent document

Patent document 1: japanese patent No. 6103611

Non-patent document

Non-patent document 1: takeshi Ogata, Hydrometallurgy,152(2015)178-

Non-patent document 2: tomohiro Shinozaki, Ind.Eng.chem.Res.,57(2018)11424-11

Disclosure of Invention

Technical problem to be solved by the invention

An aspect of the present invention provides an adsorbent particle having a large amount of adsorption of a rare earth element and capable of desorbing the adsorbed rare earth element at a high ratio.

Means for solving the technical problem

One aspect of the invention relates to an adsorbent material particle comprising: carrier particles comprising an organic polymer; an amino-containing polymer attached to the surface of the carrier particle and comprising a structural unit having an amino group; and diglycolic acid residues bonded to the amino groups of the amino-containing polymer.

Another aspect of the invention relates to a method of making adsorbent material particles, comprising: preparing substrate particles comprising carrier particles containing an organic polymer and an amino group-containing polymer attached to the surface of the carrier particles and having an amino group; and bonding diglycolic acid or anhydride thereof to the amino group of the amino group-containing polymer, thereby forming adsorbent material particles.

Yet another aspect of the invention relates to a substrate particle comprising: carrier particles comprising an organic polymer; and an amino group-containing polymer attached to the surface of the carrier particle and including a structural unit having an amino group.

Still another aspect of the present invention relates to a packed column including a column tube and the adsorbent particles packed in the column tube.

Yet another aspect of the present invention relates to a method for recovering rare earth elements, which comprises: bringing the adsorbent particles into contact with a solution containing a rare earth element, thereby adsorbing the rare earth element to the adsorbent particles; and separating the rare earth element from the adsorption material particle by contact with an acidic solution containing an acid.

Effects of the invention

An aspect of the present invention provides an adsorbent particle having a large amount of adsorption of a rare earth element and capable of desorbing the adsorbed rare earth element at a high ratio.

Drawings

FIG. 1 is a schematic view showing an embodiment of a packed column.

Fig. 2 is a graph showing the amount of adsorption and desorption of dysprosium by the adsorbent particles.

Fig. 3 is a graph showing the recovery rate of dysprosium by the adsorbent particles.

Detailed Description

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

An adsorbent particle according to an embodiment includes: carrier particles comprising an organic polymer; an amino-containing polymer attached to the surface of the support particle; and diglycolic acid residues bonded to amino groups of the amino-containing polymer.

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%.

The organic polymer may be a polymer containing a crosslinkable monomer as a monomer unit. Examples of the crosslinkable monomer include divinyl compounds such as divinylbenzene, divinylbiphenyl, divinylnaphthalene, and divinylphenanthrene. These crosslinking monomers may be used alone or in combination of two or more. The crosslinkable monomer may be divinylbenzene as a styrene-based monomer from the viewpoint of durability, acid resistance and alkali resistance. The proportion of the monomer unit derived from the crosslinkable monomer in the organic polymer may be 1 to 80 mol%, 1 to 60 mol%, or 1 to 40 mol% based on all the monomer units constituting the organic polymer.

The organic polymer may be a copolymer of a crosslinkable monomer and a monofunctional monomer. Examples of the monofunctional monomer include styrene monomers (styrene and styrene derivatives) such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α -methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, 2, 4-dimethylstyrene, p-n-butylstyrene, p-t-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3, 4-dichlorostyrene. These may be used alone or in combination of two or more. The functional monomer may be styrene from the viewpoint of acid resistance and alkali resistance.

The organic polymer may contain a monomer having a reactive group that reacts with an amino group as a monomer unit, or may be a copolymer containing a crosslinkable monomer and a monomer having a reactive group as monomer units. The reactive group may be, for example, an epoxy group, a chlorine group, or a combination thereof. Examples of the monomer having an epoxy group include glycidyl methacrylate. Examples of the monomer having a chlorine 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%, 15 to 65 mol%, 30 to 80 mol%, or 30 to 65 mol% with respect to all monomer units constituting the organic polymer.

The average particle diameter of the carrier particles may be 100 to 1000 μm, or 200 to 1000 μm. If the average particle diameter of the carrier particles becomes smaller, the pressure of the packed column packed with the adsorbent particles may increase. Here, the average particle diameter of the carrier particles can be determined by the following measurement method.

1) The particles were dispersed in water (a dispersant such as a surfactant was included) to prepare a dispersion containing 1 mass% of the particles.

2) The average particle diameter was measured from about 1 ten thousand images of particles in the dispersion using a flow particle image analyzer.

The support particles may be porous polymer particles. In the case of porous polymer particles, the surface of the porous interior is also included in the "surface of the support particle". When the support particles are porous polymer particles, the specific surface area thereof may be 50m²A ratio of 1000m or more per g²The ratio of the carbon atoms to the carbon atoms is less than g. When the specific surface area is large, the amount of adsorption of the substance tends to be large. In the present specification, the specific surface area refers to a value measured by a BET method using nitrogen as an adsorbed substance.

Amino-containing polymers are polymers comprising structural units having amino groups. The amino group-containing polymer may also be a homopolymer of a monomer having an amino group. The structural unit having an amino group may be a group composed of an amino group and an aliphatic group or a residue of an aliphatic amino acid. Examples of the amino group-containing polymer include polyethyleneimine and polylysine. The polyethyleneimine may be branched or linear, and may contain 3 or more structural units derived from aziridine.

The molecular weight of the amino group-containing polymer may be 200 or more and 10000 or less or 7000 or less, and may be 250 or more and 10000 or less or 7000 or less.

At least a portion of the amino-containing polymers attached to the surface of the support particles may be bonded to the organic polymer by covalent bonds. For example, in the case where the organic polymer has a reactive group, the amino group-containing polymer can be bonded to the organic polymer through a covalent bond by the reaction of the reactive group with the amino group.

The amount of the amino group-containing polymer may be, for example, 5 to 50% by weight, 10 to 50% by weight, 5 to 40% by weight, or 10 to 40% by weight based on the mass of the carrier particles. The amount of amino groups in the adsorbent particles may be 0.1 to 100mmol, 0.1 to 50mmol, 0.5 to 100mmol, or 0.5 to 20mmol per 1g of the adsorbent particles.

The amount of the amino group in the adsorbent particles or the base material particles described later can be determined by a method of measuring the amount of sulfuric acid consumed by the reaction with the amino group by titration with sodium hydroxide. The method of determining the amount of amino groups in the substrate particles includes the following operations.

1) Methanol was added to base material particles (A) g, and the resulting dispersion was heated at 75 ℃ for 30 minutes.

2) From the dispersion, the substrate particles were recovered onto the filter by suction filtration. While continuing the suction, pure water was added to the substrate particles on the filter to replace methanol with pure water, and then the substrate particles were adjusted with a small amount of 0.1M aqueous sodium hydroxide solution. Then, the substrate particles were washed with pure water until the filtrate became neutral.

3) The cleaned substrate particles were transferred to a glass container using a small amount of pure water. The total amount of pure water in the vessel was adjusted to (B) g.

4) 0.05M g of sulfuric acid (C) was added to the dispersion in the vessel, and then, the dispersion in the vessel was stirred at 150rpm at room temperature for 30 minutes.

5) The supernatant (D) g of the dispersion was collected, and pure water was added thereto to adjust the amount of the liquid.

6) The diluted supernatant was titrated with 0.01M aqueous sodium hydroxide solution, and the amount of aqueous sodium hydroxide solution (E) mL required for neutralization was recorded.

7) The amount of amino groups was calculated by the following formula.

The amount of amino groups (mmol/g) [ {0.1 × C × D/(B + C) -0.01 × E } × (B + C)/D ]/a

For example, as represented by the following formula, the diglycolic acid residue is a 1-valent group bonded to the amino group of the amino group-containing polymer. Wherein the amino group is an amino group of the amino group-containing polymer, and the moiety excluding the amino group is a diglycolic acid residue.

Through the interaction of diglycolic acid residues and rare earth complexes, the adsorbing material particles can adsorb rare earth elements.

The adsorbent particles can be produced by a method including, for example: preparing substrate particles comprising carrier particles and an amino group-containing polymer attached to the surface of the carrier particles, and having no diglycolic acid residues; and bonding diglycolic acid or anhydride thereof to the amino group of the amino group-containing polymer, thereby forming adsorbent particles.

The base material particles are produced by attaching an amino group-containing polymer to the surface of the carrier particles. An example of a method for preparing the substrate particles when the carrier particles contain an organic polymer having a reactive group includes: producing support particles as porous particles by suspension polymerization in a reaction solution containing a monomer component (including a monomer having a reactive group), a porosifier, and an aqueous medium; and bonding the amino-containing polymer to the organic polymer by reaction of the reactive group with the amino-containing polymer.

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

The amount of the porosigen may be 0 to 300 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 porosifier. The size and shape of the pores of the porous polymer particles can be controlled by the type of the porosifier.

The aqueous medium may comprise water. The water can be made to function as a porosifier. 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 absorb water to promote phase separation in the particles. By removing one phase from the phase-separated particles, the particles become porous.

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 comprise a surfactant. The surfactant may be anionic, cationic, nonionic or zwitterionic.

The reaction liquid for suspension polymerization may contain a polymerization initiator. Examples of the polymerization initiator include organic peroxides such as benzoyl peroxide, lauroyl peroxide, o-chlorobenzoyl peroxide, o-methoxybenzoyl peroxide, 3,5, 5-trimethylhexanoyl peroxide, t-butylperoxy-2-ethylhexanoate, and di-t-butylperoxide; and azo compounds such as 2,2 ' -azobisisobutyronitrile, 1 ' -azobiscyclohexane carbonitrile, 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 component.

In order to improve dispersion stability of the particles containing the monomer component, the reaction liquid may contain a dispersion stabilizer. Examples of the dispersion stabilizer include polyvinyl alcohol, polycarboxylic acid, cellulose (hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, etc.), and polyvinylpyrrolidone. These inorganic water-soluble high molecular compounds such as sodium tripolyphosphate may also be used in combination. The dispersion stabilizer may be polyvinyl alcohol or polyvinyl pyrrolidone. The amount of the dispersion stabilizer may be 1 to 10 parts by mass relative to 100 parts by mass of the monomer.

The reaction solution used for suspension polymerization may contain water-soluble polymerization inhibitors such as nitrites, sulfites, hydroquinones, ascorbic acids, water-soluble vitamin B compounds, citric acid, polyphenols and the like.

The polymerization temperature for suspension polymerization can be appropriately selected depending on the types of monomers and polymerization initiators. The polymerization temperature may be 25 to 110 ℃ or 50 to 100 ℃.

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

If necessary, after the substrate particles are washed and dried, diglycolic acid or an anhydride thereof is bonded to the amino group of the amino group-containing polymer attached to the carrier particles. This reaction can be carried out, for example, in a reaction solution containing the base particles, diglycolic acid or an acid anhydride thereof, and a solvent, while heating, if necessary. The solvent is not particularly limited and may be, for example, tetrahydrofuran. The reaction results in the formation of adsorbent particles into which diglycolic acid residues have been introduced. The formed adsorbent material particles are washed and dried as necessary.

The adsorbent particles or separator particles into which ligands other than diglycolic acid residues have been introduced can be obtained by using substrate particles comprising carrier particles and an amino group-containing polymer attached to the surfaces of the carrier particles. The average particle diameter of the base material particles is generally substantially the same as the average particle diameter of the adsorbent particles.

The rare earth element can be efficiently recovered by a method comprising: bringing a solution containing a rare earth element into contact with the adsorbent particles, thereby adsorbing the rare earth element to the adsorbent particles; and separating the rare earth element from the adsorbent particles in an acidic solution containing an acid.

The temperature of the solution for adsorption and the acidic solution for desorption is not particularly limited, and may be, for example, 15 to 35 ℃. 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 can efficiently recover the rare earth element based on a large adsorption amount of the adsorbent particles and effective desorption of the adsorbed rare earth element. The adsorbent particles according to the present embodiment have higher resistance to acids than an adsorbent containing silica particles as carrier particles, and therefore are advantageous in that deterioration is small even when used repeatedly.

The pH of the solution when the rare earth element is adsorbed to the adsorbent particles may be about 1.0 to 2.0. The acidity of the acidic solution for removing the rare earth element having acidity is adjusted to a strength at which the rare earth element is appropriately removed. For example, the acid concentration of the acidic solution can be 2 gram equivalents/L or less, 1 gram equivalents/L or less, or 0.5 gram equivalents/L or less. The adsorbent particles according to the present embodiment can efficiently desorb the rare earth element even when a relatively weakly acidic solution is used. The use of a weakly acidic solution is advantageous 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 rare earth element to be recovered may be any of scandium, yttrium and lanthanum-based elements, or lanthanum-based elements such as dysprosium and neodymium. The solution containing the recovered rare earth element may be an aqueous solution. The rare earth elements in solution are typically dissolved as cations in a solvent (e.g., water).

The adsorbent particles may be used as a column packing agent. FIG. 1 is a schematic view showing an embodiment of a packed column. The packed column 10 shown in fig. 1 includes a cylindrical column body 11, a connecting part 12, and a column packing 13 containing the adsorbent particles according to the above embodiment. The connecting portions 12 are disposed at both ends of the column body 11 to connect the column body 11 to the column chromatography apparatus. The column packing 13 is filled in the cylindrical column body 11. The material of the column 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 13 containing the adsorbent particles is usually packed in the column body 11 together with a solvent. The solvent is not particularly limited as long as it is a solvent in which the adsorbent particles are dispersible, and may be, for example, water.

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

Examples

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

1. Production of adsorbent particles

Example 1

Substrate particle

Porous polymer particles (specific surface area: 330 m) comprising a divinylbenzene-glycidyl methacrylate copolymer were prepared²Per g) as support particles. The porous polymer particles were added to methanol, and the suspension was stirred with shaking, thereby wetting the porous polymer particles with methanol. Then, the suspension was filtered while maintaining the wet state using pure water, thereby replacing methanol with pure water. A suspension containing pure water and wetted porous polymer particles was added with polyethyleneimine (molecular weight 300, amine number 21mmol/g) in an amount such that the mass ratio of water to polyethyleneimine was 1: 2. Subsequently, the suspension was heated at 80 ℃ for 8 hours, whereby the epoxy groups of the porous polymer particles reacted with polyethyleneimine. The porous polymer particles extracted by filtration were thoroughly washed with ethanol and water, and then dried at 80 ℃ for 15 hours to obtain polyethyleneimine-introduced substrate particles. The average particle diameter of the obtained base particles was 400. mu.m, and the amount of amino groups per 1g of the base particles was 2.5 mmol. The specific surface area of the substrate particles was estimated to be 250m²And about/g.

Adsorbent particles

1.2g of substrate particles and 5.6g of diglycolic acid anhydride were reacted in tetrahydrofuran at 50 ℃ for 8 hours. The particles extracted by filtration were thoroughly washed with ethanol and water, and then dried at 80 ℃ for 15 hours, thereby obtaining adsorbent particles into which diglycolic acid residues were introduced.

Example 2

Adsorbent particles into which diglycolic acid residues were introduced were obtained in the same manner as in example 1, except that polyethyleneimine having a molecular weight of 600 and an amine value of 20mmol/g was used as polyethyleneimine. The average particle diameter of the base particles was 400. mu.m, and the amount of amino groups per 1g of the base particles was 2.6 mmol. The specific surface area of the substrate particles was estimated to be 250m²And about/g.

Example 3

Adsorbent particles into which diglycolic acid residues were introduced were obtained in the same manner as in example 1, except that polyethyleneimine having a molecular weight of 1200 and an amine value of 19mmol/g was used as the polyethyleneimine. The average particle diameter of the base particles was 400. mu.m, and the amount of amino groups per 1g of the base particles was 3.5 mmol. The specific surface area of the substrate particles was estimated to be 250m²And about/g.

Example 4

Porous polymer particles composed of the same divinylbenzene-glycidyl methacrylate copolymer as in example 1 were prepared as support particles. The porous polymer particles were added to methanol, and the suspension was stirred with shaking, thereby wetting the porous polymer particles with methanol. Then, the suspension was filtered while maintaining the wet state using pure water, thereby replacing methanol with pure water. Next, the solvent of the suspension was replaced with an aqueous solution of polylysine (concentration: 10% by mass, molecular weight: about 5000) from pure water. The epoxy groups of the porous polymer particles were reacted with polylysine by heating at 80 ℃ for 8 hours. The porous polymer particles extracted by filtration were thoroughly washed with ethanol and water, and then dried at 80 ℃ for 15 hours, thereby obtaining polylysine-introduced substrate particles. The average particle diameter of the base particles was 400. mu.m, and the amount of amino groups per 1g of the base particles was 3.4 mmol. The specific surface area of the substrate particles was estimated to be 250m²And about/g.

Adsorbent particles into which diglycolic acid residues were introduced were obtained in the same manner as in example 1, except that the obtained base particles were used.

Example 5

Polymer particles composed of a chloromethylated styrene-divinylbenzene copolymer were prepared as carrier particles. The polymer particles were added to methanol, and the suspension was shaken and stirred, thereby wetting the porous polymer particles with methanol. Then, filtration was performed while maintaining the wet state using pure water, thereby replacing methanol with pure water. A suspension containing pure water and wetted polymer particles was added with polyethyleneimine (molecular weight 600, amine value 20mmol/g) in an amount such that the mass ratio of water to polyethyleneimine was 1:2, and the suspension was heated at 80 ℃ for 8 hours, thereby reacting the chloromethyl group of the polymer particles with the polyethyleneimine. The polymer particles extracted by filtration were thoroughly washed with ethanol and water, and then dried at 80 ℃ for 15 hours to obtain polyethyleneimine-introduced substrate particles. Adsorbent particles into which diglycolic acid residues were introduced were obtained in the same manner as in example 1, except that the obtained base particles were used.

Comparative example 1

Porous polymer particles composed of the same divinylbenzene-glycidyl methacrylate copolymer as in example 1 were prepared as support particles. The porous polymer particles were added to methanol, and the suspension was stirred with shaking, thereby wetting the porous polymer particles with methanol. Then, the suspension was filtered while maintaining the wet state using pure water, thereby replacing methanol with pure water. Next, the solvent of the suspension was replaced from pure water to ethylenediamine in the same manner. The suspension was heated at 80 ℃ for 8 hours, whereby the epoxy groups of the porous polymer particles were reacted with ethylenediamine. The porous polymer particles extracted by filtration were thoroughly washed with ethanol and water, and then dried at 80 ℃ for 15 hours, thereby obtaining ethylenediamine-introduced substrate particles. The average particle diameter of the base particles was 400. mu.m, and the amount of amino groups per 1g of the base particles was 2.4 mmol. The specific surface area of the substrate particles was estimated to be 250m²And about/g.

Adsorbent particles into which diglycolic acid residues were introduced were obtained in the same manner as in example 1, except that the obtained base particles were used. The adsorbent particles had a specific surface area of 202m²/g。

Comparative example 2

Silica particles having an amino group (3-aminopropyl silica gel, manufactured by Tokyo Chemical industry co., ltd.) were prepared as the carrier particles. The silica particles were reacted with diglycolic acid anhydride in tetrahydrofuran at 50 ℃ for 8 hours. The silica particles extracted by filtration were thoroughly washed with ethanol and water, and then dried at 80 ℃ for 15 hours, thereby obtaining adsorbent particles into which diglycolic acid residues were introduced.

2. Evaluation of

2-1 adsorption test

5mL of an aqueous solution for adsorption test having a concentration of 160ppm, containing dysprosium (Dy) and having a pH adjusted to 1.0 or 1.3 was prepared. 50mg of each adsorbent particle was added to the aqueous solution. The suspension containing the adsorbent particles was vibrated while being maintained at 25 ℃. Dysprosium ions were adsorbed to the adsorbent particles by 24-hour vibration, and then the concentration of dysprosium ions in the aqueous solution was measured by an ICP emission spectrometer for an aqueous solution extracted from the suspension. The amount of adsorption of dysprosium ions (μmol/g) per 1g of the adsorbent particles was calculated from the difference in ion concentration between before and after adsorption.

2-2. detachment test

Hydrochloric acid was added to the suspension containing the adsorbent particles after the adsorption test was completed, whereby the pH of the suspension was adjusted to-0.3 corresponding to a hydrochloric acid concentration of 2 gram equivalents/L. The suspension having a pH of-0.3 was vibrated for 3 hours while being maintained at 25 ℃, thereby separating dysprosium ions from the adsorbent particles. The concentration of dysprosium ions in the aqueous solution was measured by an ICP emission analyzer for the aqueous solution extracted from the suspension. The amount of released dysprosium ions (released amount, μmol/g) per 1g of the adsorbent particles was calculated from the difference in ion concentration between before and after the release.

The amount of dysprosium ions desorbed (desorption amount) per 1g of the adsorbent particles was determined in the same manner as described above except that the pH of the suspension used for desorption was changed to 0.3 corresponding to a hydrochloric acid concentration of 0.5 gram equivalent/L.

[ Table 1]

As shown in table 1, the adsorbent particles of each example showed significantly larger adsorption amount and desorption amount than the adsorbent particles of comparative example 1 into which ethylenediamine and diglycolic acid residues were introduced. Fig. 2 is a graph showing the adsorption amount of dysprosium ions when adsorbed onto the adsorbent particles at a pH of 1.3 and the desorption amount of dysprosium ions when desorbed at a pH of-0.3 (2 g eq/L HCl) with respect to the adsorbent particles of example and comparative example 1.

Fig. 3 is a graph showing the recovery rate, which is the ratio of the desorption amount to the adsorption amount, of the adsorbent particles of the example in which dysprosium ions are adsorbed at pH 1.3. For comparison, fig. 3 also shows the recovery rate obtained by the same method as described above with respect to the adsorbent particle of comparative example 2, which is a silica particle having diglycolic acid residues introduced therein. It was confirmed that the adsorbent particles of the example containing particles composed of an organic polymer as carrier particles were significantly superior in recovery efficiency by desorption, as compared with the adsorbent particles of comparative example 2 containing silica particles as carrier particles.

2-3 acid resistance test

The adsorbent particles of each of examples and comparative example 2 were immersed in 2g eq/L hydrochloric acid. The mixture of adsorbent material particles and hydrochloric acid was stirred at 25 ℃ for 30 days. Then, the amount of adsorption of dysprosium ions by the adsorbent particles after hydrochloric acid treatment was measured by the same operation as in the adsorption test described above. The adsorption amount of the adsorbent particles of comparative example 2 was reduced by 10% or more compared to that before hydrochloric acid treatment. In contrast, in the case of the adsorbent particles of each example, the adsorption amount was maintained at an amount close to the adsorption amount before the hydrochloric acid treatment, and the reduction ratio of the adsorption amount was less than 10%.

Description of the symbols

10-packed column, 11-column body, 12-connector, 13-column filler.