A green process for the extraction of lanthanide elements

Patent metadata

Field	Value
Publication number	US-2024417826-A1
Application number	US-202218706892-A
Country	US
Kind code	A1
Filing date	Nov 4, 2022
Priority date	Nov 5, 2021
Publication date	Dec 19, 2024
Grant date	—

Abstract

A method for extracting at least one lanthanide element, preferably selected from lanthanum (La), praseodymium (Pr), neodymium (Nd), europium (Eu), dysprosium (Dy), and ytterbium (Yb), from a solid material including the lanthanide element, one or more waste elements such as iron (Fe), and/or one or more other lanthanide elements. The method implements a composition including water, at least one organic aprotic solvent, and at least one charged hydrotrope. Also, the use of the composition for recycling lanthanide elements, and more particularly WEEE, and for the decontamination of effluents.

First claim

1 - 16 . (canceled)

17 . A method for extracting at least one first lanthanide element having a molecular weight M L1 (in g/mol) from a solid material comprising said first lanthanide element and one or more other element(s) selected from a second lanthanide element having a molecular weight M L2 (in g/mol), at least one waste element having a molecular weight M WE (in g/mol), and mixture thereof, wherein:
M WE ≤100 g/mol, and when the other element is a second lanthanide element, eventually in mixture with a waste element, M L1 ≥154 g/mol and preferably M L1 ≥160 g/mol, and M L2 <154 g/mol, and wherein said method comprises at least the following steps: i) preparing a leaching composition comprising an aqueous phase, at least one organic aprotic solvent, and at least one charged hydrotrope, ii) mixing the leaching composition with the solid material so as to form a leachate solution comprising the first lanthanide element, and a solid residue comprising said one or more other element(s), and iii) separating the leachate solution from the solid residue.

18 . The method according to claim 17 , wherein the charged hydrotrope is a cationic hydrotrope selected from salts of a substituted benzoic acid, a unsubstituted benzoic acid, a substituted benzene sulfonic acid, and a unsubstituted benzene sulfonic acid.

19 . The method according to claim 17 , wherein the charged hydrotrope represents from 20% to 50% by mass, with respect to the total mass of the leaching composition.

20 . The method according to claim 17 , wherein the organic aprotic solvent is selected from ethers, esters, carbonates, and mixtures thereof.

21 . The method according to claim 17 , wherein the organic aprotic solvent represents from 10% to 40% by mass, with respect to the total mass of the leaching composition.

22 . The method according to claim 17 , wherein the aqueous phase has a pH ranging from 6.5 to 7.5.

23 . The method according to claim 17 , wherein the solid material is a WEEE or a permanent magnet.

24 . The method according to claim 17 , wherein the waste element is a transition metal or a metalloid selected from iron, copper, cobalt, boron, nickel, aluminium, titanium, chromium, and vanadium.

25 . The method according to claim 17 , wherein the solid material comprises one or more waste elements as the other element(s) and the first lanthanide element is selected from lanthanum (La), praseodymium (Pr), neodymium (Nd), europium (Eu), dysprosium (Dy), and ytterbium (Yb).

26 . The method according to claim 17 , wherein the solid material comprises a second lanthanide element eventually in mixture with one or more waste element(s) as other element(s), the first lanthanide is dysprosium (Dy) or ytterbium (Yb), and the second lanthanide element is selected from lanthanum (La), praseodymium (Pr), neodymium (Nd), and europium (Eu).

27 . The method according to claim 17 , further comprising after step iii):
a step iv) of adding a precipitating agent to the leachate solution so as to form a solid comprising said first lanthanide element, a step v) after step iv) of separating the solid comprising said first lanthanide element from the remaining solution, and a step vi) after step v) of calcining the solid comprising said first lanthanide element so as to form an oxidized form of the first lanthanide element.

28 . The method according to claim 17 , wherein:
the solid material further comprises a third lanthanide element having a molecular weight M L3 such that M L3 ≥154 g/mol, with M L3 <M L1 , and the leachate solution obtained in step iii) is enriched in first and third lanthanide elements, and said method further comprises selectively extracting the first lanthanide element with respect to the third lanthanide element after step iii) according to the following steps: a) mixing a dilution solution comprising an organic aprotic solvent as defined in the preceding claims and water, with the leachate solution comprising the first and third lanthanide elements obtained in step iii), so as to obtain a resulting biphasic composition comprising an organic-rich phase comprising the first lanthanide element, and an aqueous-rich phase comprising the third lanthanide element, b) separating the two phases so as to recover the aqueous-rich phase comprising the third lanthanide element, c) mixing the organic-rich phase comprising the first lanthanide element with an aqueous acidic solution so as to obtain a resulting biphasic composition comprising an aqueous-rich phase comprising the first lanthanide element, and an organic-rich phase, and d) separating the two phases so as to recover the aqueous-rich phase comprising the first lanthanide element.

29 . The method according to claim 17 , wherein the solid material comprises a second lanthanide element eventually in mixture with one or more waste element(s) as other element(s), and said method further comprises after step iii) at least the following steps I), II) and III):
I) preparing a leaching composition comprising an aqueous phase, at least one organic aprotic solvent, and at least one charged hydrotrope, II) mixing the leaching composition of step I) with the solid residue of step iii) so as to form a leachate solution comprising the second lanthanide element, and a solid residue comprising one or more other element(s), and III) separating the leachate solution from the solid residue.

30 . The method according to claim 17 , wherein:
the solid material further comprise a fourth lanthanide element having a molecular weight M L4 such that M L4 <154 g/mol, with M L4 <M L2 , the leachate solution obtained in step III) is enriched in second and fourth lanthanide elements, and said method further comprises selectively extracting the second lanthanide element with respect to the fourth lanthanide element after step III) according to the following steps: A) mixing a dilution solution comprising an organic aprotic solvent as defined in the preceding claims and water, with the leachate solution comprising the second and fourth lanthanide elements obtained in step III), so as to obtain a resulting biphasic composition comprising an organic-rich phase comprising the second lanthanide element, and an aqueous-rich phase comprising the fourth lanthanide element, B) separating the two phases so as to recover the aqueous-rich phase comprising the fourth lanthanide element, and C) mixing the organic-rich phase comprising the second lanthanide element with an aqueous acidic solution so as to obtain a resulting biphasic composition comprising an aqueous-rich phase comprising the second lanthanide element, and an organic-rich phase, and D) separating the two phases so as to recover the aqueous-rich phase comprising the second lanthanide element.

31 . A method for recycling lanthanide elements, and more particularly WEEE, comprising mixing a solid material with a leaching composition comprising an aqueous phase, at least one organic aprotic solvent, and at least one charged hydrotrope.

32 . A method for decontaminating effluents, comprising mixing an effluent with a leaching composition comprising an aqueous phase, at least one organic aprotic solvent, and at least one charged hydrotrope.

Assignees

• Commissariat Energie Atomique
• Centre Nat Rech Scient
• Univ Montpellier
• Enscm

Inventors

• Zemb Thomas
• El Maangar Asmae
• Pellet-Rostaing Stéphane

Classifications

• C22B7/007

  by acid leaching · CPC title

• C22B3/44

  by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42) · CPC title

• C22B3/16

  in organic solutions · CPC title

• Y02P10/20

  Recycling · CPC title

• C22B7/006

  Wet processes · CPC title