Adsorbent particles, method for producing adsorbent particles, base material particles, filling column and method for recovering rare earth element

1. Adsorbent particles for recovering a rare earth element, each of the adsorbent particles comprising:

a carrier particle containing an organic polymer;

an amino group-containing polymer adhered to a surface of the carrier particle; and

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

wherein the amino group-containing polymer comprises polyethyleneimine, polylysine, or a mixture thereof and has a molecular weight of 200 or more and 10,000 or less, and

wherein the diglycolic acid residue interacts with and adsorbs the rare earth element to be recovered.

2. The adsorbent particles according to claim 1 , wherein the organic polymer is a polymer including a monomer unit derived from a styrene-based monomer.

3. The adsorbent particles according to claim 1 , wherein the carrier particle is a porous polymer particle.

4. The adsorbent particles according to claim 1 , wherein the quantity of the amino groups in the adsorbent particles is 0.1 to 100 mmol per 1 g of the adsorbent particles.

5. A packed column comprising:

a column tube; and

the adsorbent particles according to claim 1 , packed in the column tube.

6. A method for recovering a rare earth element, the method comprising:

bringing a solution containing the rare earth element into contact with the adsorbent particles according to claim 1 and thereby causing the rare earth element to be adsorbed to the adsorbent particles; and

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

7. The method according to claim 6 , wherein an acid concentration of the acidic solution is 0.5 N or lower.

8. A method for producing adsorbent particles for recovering a rare earth element, the method comprising:

preparing base material particles, each of the base material particles comprising:

a carrier particle containing an organic polymer, and

an amino group-containing polymer adhered to a surface of the carrier particle; and

causing diglycolic acid or an anhydride thereof to bond to the amino group of the amino group-containing polymer and thereby forming the adsorbent particles,

wherein the amino group-containing polymer comprises polyethyleneimine, polylysine, or a mixture thereof, and has a molecular weight of 200 or more and 10,000 or less, and

wherein the adsorbent particle comprises a diglycolic acid residue derived from the diglycolic acid or an anhydride thereof, and the diglycolic acid residue interacts with and adsorbs the rare earth element to be recovered.

9. The method according to claim 8 , wherein the organic polymer includes a constituent unit having a reactive group, and

wherein the base material particles are prepared, at least in part, by causing the amino group-containing polymer to bond to the organic polymer by a reaction between the reactive group and the amino group-containing polymer.