Methods of recovering rare earth elements

Patent metadata

Field	Value
Publication number	US-10954585-B2
Application number	US-201916254401-A
Country	US
Kind code	B2
Filing date	Jan 22, 2019
Priority date	Jan 23, 2018
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A method of recovering a rare earth element. The method comprises dissolving a rare earth element magnetic material in a dissolution organic solvent and a β-diketone compound to form a dissolved rare earth element mixture. A rare earth element of the rare earth element magnetic material and the β-diketone compound are reacted to form a β-diketonate chelate complex and the dissolution organic solvent is removed. The β-diketonate chelate complex is removed using a separation organic solvent, and the β-diketonate chelate complex is recovered. Additional methods are also disclosed.

First claim

What is claimed is:

1. A method of recovering a rare earth element, comprising:
dissolving a rare earth element magnetic material in a dissolution organic solvent and a β-diketone compound to form a dissolved rare earth element mixture;
reacting a rare earth element of the rare earth element magnetic material and the β-diketone compound to form a β-diketonate chelate complex;
removing the dissolution organic solvent from the dissolved rare earth element mixture;
removing the β-diketonate chelate complex from the dissolved rare earth element mixture using a separation organic solvent; and
recovering the β-diketonate chelate complex.

2. The method of claim 1 , wherein dissolving a rare earth element magnetic material in a dissolution organic solvent and a β-diketone compound comprises dissolving a rare earth element magnetic material comprising the rare earth element and a transition metal in the dissolution organic solvent and the β-diketone compound.

3. The method of claim 1 wherein dissolving a rare earth element magnetic material in a dissolution organic solvent and a β-diketone compound comprises dissolving the rare earth element magnetic material in a non-aqueous solution.

4. The method of claim 1 , wherein dissolving a rare earth element magnetic material in a dissolution organic solvent and a β-diketone compound comprises dissolving the rare earth element magnetic material in the dissolution organic solvent and a β-diketone compound selected from the group consisting of 2,4-pentadione or acetylacetone (AcAc), 1,1,1-trifluoro-2,4-pentadione (TFA), 1,1,1,5,5,5-hexafluoro-2,4-pentadione (HFA), 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione (TFBA), 1,1,1, 2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedione (FOD), 3-methyl-2,4-pentadione, or combinations thereof.

5. The method of claim 1 , wherein dissolving a rare earth element magnetic material in a dissolution organic solvent and a β-diketone compound comprises dissolving the rare earth element magnetic material in toluene, acetonitrile, or combinations thereof.

6. The method of claim 1 , wherein dissolving a rare earth element magnetic material in a dissolution organic solvent and a β-diketone compound comprises dissolving a neodymium-iron-boride magnetic material in the dissolution organic solvent and β-diketone compound.

7. The method of claim 1 , wherein removing the β-diketonate chelate complex from the dissolved rare earth element mixture using a separation organic solvent comprises continuously extracting the β-diketonate chelate complex with the separation organic solvent.

8. The method of claim 1 , wherein removing the β-diketonate chelate complex from the dissolved rare earth element mixture using a separation organic solvent comprises removing the β-diketonate chelate complex using xylene.

9. The method of claim 1 , wherein removing the β-diketonate chelate complex from the dissolved rare earth element mixture using a separation organic solvent comprises separating the β-diketonate chelate complex from reaction products not soluble in the separation organic solvent.

10. The method of claim 1 , further comprising recovering the rare earth element from the β-diketonate chelate complex.

11. A method of recovering a rare earth element, comprising:
combining a rare earth element material with a dissolution organic solvent and a β-diketone compound to form a rare earth element mixture;
reacting a rare earth element of the rare earth element material with the β-diketone compound to form a rare earth element β-diketonate chelate complex;
removing the dissolution organic solvent from the rare earth element mixture;
separating the rare earth element β-diketonate chelate complex from the rare earth element mixture using a separation organic solvent; and
recovering the rare earth element from the rare earth element β-diketonate chelate complex.

12. The method of claim 11 , wherein combining a rare earth element material with a dissolution organic solvent and a β-diketone compound to form a rare earth element mixture comprises forming the rare earth element mixture comprising the rare earth element and a transition metal.

13. The method of claim 11 , wherein reacting a rare earth element of the rare earth element material with the β-diketone compound to form a rare earth element β-diketonate chelate complex comprises forming the rare earth element β-diketonate chelate complex and a transition metal β-diketonate chelate complex.

14. The method of claim 13 , wherein separating the rare earth element β-diketonate chelate complex from the rare earth element mixture comprises separating the rare earth element β-diketonate chelate complex and the transition metal β-diketonate chelate complex.

15. The method of claim 11 , further comprising converting the rare earth element β-diketonate chelate complex to a rare earth element oxide or a rare earth element salt.

16. A method of recovering a rare earth element, comprising:
dissolving a material comprising neodymium in a dissolution organic solvent and a β-diketone compound to form a rare earth element mixture;
reacting the neodymium with the β-diketone compound to form a neodymium β-diketonate chelate complex;
removing the dissolution organic solvent from the rare earth element mixture;
separating the neodymium β-diketonate chelate complex from the rare earth element mixture using a separation organic solvent; and
recovering the neodymium β-diketonate chelate complex.

17. The method of claim 16 , wherein dissolving a material comprising neodymium comprises dissolving a neodymium-iron-boride material in the dissolution organic solvent and β-diketone compound.

18. The method of claim 16 , wherein recovering the neodymium β-diketonate chelate complex comprises separating the neodymium β-diketonate chelate complex from a transition metal β-diketonate chelate complex.

19. The method of claim 16 , wherein recovering the neodymium β-diketonate chelate complex comprises separating the neodymium β-diketonate chelate complex from an iron β-diketonate chelate complex.

20. The method of claim 16 , further comprising recovering the neodymium.

21. The method of claim 1 , wherein dissolving a rare earth element magnetic material in a dissolution organic solvent and a β-diketone compound comprises dissolving a magnetic material comprising cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, praseodymium, promethium, samarium, scandium, terbium, thulium, ytterbium, yttrium, or a combination thereof in the dissolution organic solvent and β-diketone compound.

Assignees

• Battelle Energy Alliance Llc

Inventors

• Klaehn John
• Rollins Harry W
• Mcnally Joshua S

Classifications

• C22B3/1641

  with ketones or aldehydes · CPC title

• Y02P10/20

  Recycling · CPC title

• C22B3/22

  by physical processes, e.g. by filtration, by magnetic means {, or by thermal decomposition} (treatment or purification of solutions by liquid-liquid extraction C22B3/26) · CPC title

• C22B59/00 Primary

  Obtaining rare earth metals · CPC title