Recovery of rare earth metals from ferromagnetic alloys

Patent metadata

Field	Value
Publication number	US-2022002890-A1
Application number	US-202117462047-A
Country	US
Kind code	A1
Filing date	Aug 31, 2021
Priority date	Jul 1, 2020
Publication date	Jan 6, 2022
Grant date	—

Abstract

Methods for recovery of at least one rare earth metal from ferromagnetic alloy are described, and further methods of atomic hydrogen decrepitation of a ferromagnetic alloy.

First claim

What is claimed is:

1 . A method of atomic hydrogen decrepitation of a ferromagnetic alloy, wherein the method comprises an electrolytic reaction of a ferromagnetic alloy by atomic hydrogen at room temperature, wherein the atomic hydrogen is released from a cathode within an electrochemical cell and reacted with the ferromagnetic alloy to obtain a ferromagnetic alloy powder having grain size ≤50 μm.

2 . The method of to claim 1 , wherein the ferromagnetic alloy is attached to a cathode.

3 . The method of claim 1 , wherein the atomic hydrogen decrepitation comprises an electrolytic reaction, wherein the electrolyte is a KOH or NaOH aqueous solution.

4 . The method of claim 1 , wherein the atomic hydrogen is released from the cathode by a reduction reaction of 2H + ( )+2e − →2H( ).

5 . The method of claim 4 , wherein the H+ is a result of electrolysis of the water (H2O) within the cell.

6 . The method of claim 1 , wherein the cathode is copper, nickel, steel, titanium or any combination thereof.

7 . The method of claim 1 , wherein, the anode is a lead, nickel, steel or combination thereof.

8 . The method of claim 1 , wherein the electrolytic reaction is conducted at room temperature.

9 . The method of claim 1 , wherein the electrolytic reaction is conducted at a potential is between 4-10 V.

10 . A method for recovery of at least one rare earth metal from ferromagnetic alloy, the method comprises:
(a) Pre-treating a ferromagnetic alloy by atomic hydrogen decrepitation according to claim 1 to form a powder alloy; (b) reacting the ferromagnetic powder alloy with at least one chlorine-containing gas to obtain a volatile iron-containing chloride product and non-volatile at least one rare earth metal chloride; (c) providing air flow to said volatile iron-containing chloride product, thereby oxidizing the iron-containing chloride product to iron oxide; (d) separating said iron oxide product and non-volatile at least one rare earth metal chloride; (e) cooling said separated non-volatile at least one rare earth metal chloride; (f) electrolyzing said cooled non-volatile at least one rare earth metal chloride; thereby recovering said at least one rare earth metal.

11 . A method for recovery of at least one rare earth metal from ferromagnetic alloy, the method comprises:
(a) reacting a ferromagnetic alloy with at least one chlorine-containing gas to obtain a volatile iron-containing chloride product and non-volatile at least one rare earth metal chloride; (b) providing air flow to said volatile iron-containing chloride product, thereby oxidizing the iron-containing chloride product to iron oxide; (c) separating said iron oxide product and non-volatile at least one rare earth metal chloride; (d) cooling said separated non-volatile at least one rare earth metal chloride; (e) electrolyzing said cooled non-volatile at least one rare earth metal chloride; thereby recovering said at least one rare earth metal.

12 . The method of claim 11 , wherein prior to reacting the ferromagnetic alloy with at least one chlorine-containing gas of step (a), the ferromagnetic alloy is optionally pre-treated by decrepitated to form a powder alloy using atomic hydrogen decrepitation treatment.

13 . The method of claim 12 , wherein the decrepitation is performed at room temperature.

14 . The method of claim 11 , wherein the at least one rare earth metal is selected from cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu), neodymium (Nd), praseodymium (Pr), promethium (Pm), samarium (Sm), scandium (Sc), terbium (Th), thulium (Tm), ytterbium (Yb), and yttrium (Y).

15 . The method of claim 11 , wherein the reaction of step (a) is performed at a temperature of between 400° C. and 450° C.

16 . The method of claim 11 , wherein the at least one chlorine-containing gas in reaction of step (a) is present in an amount of 0.5-2.0 kg of the chlorine per 1 kg of the ferromagnetic alloy.

17 . The method of claim 11 , wherein the air flow to the volatile iron-containing chloride product of step (b) is present in an amount of 0.5-2.0 kg of the air per 1 kg of the volatile iron-containing chloride product.

18 . The method of claim 12 wherein the atomic hydrogen decrepitation treatment is performed using electrolysis.

19 . The method of claim 18 , wherein said electrolysis is performed using a first electrode (cathode) of copper, nickel, steel, titanium or combination thereof; and a second electrode (anode) of lead, nickel, steel or combination thereof.

20 . The method of claim 19 , wherein the ferromagnetic alloy is attached to said first electrode (cathode).

21 . The method of claim 19 , wherein the ferromagnetic alloy is attached to said first electrode (cathode).

22 . At least one rare earth metal composition prepared by the method of claim 10 .

23 . At least one rare earth metal composition prepared by the method of claim 11 .

Assignees

• Yeda Res & Dev

Inventors

• Lubomirsky Igor
• Kaplan Valery

Classifications

• C25C1/06 Primary

  or iron group metals, refractory metals or manganese · CPC title

• C25C1/22 Primary

  of metals not provided for in groups C25C1/02 - C25C1/20 · CPC title

• C25C5/00 Primary

  Electrolytic production, recovery or refining of metal powders or porous metal masses · CPC title

• C22B1/005 Primary

  Preliminary treatment of scrap (C22B1/02 - C22B1/26 take precedence) · CPC title

• C22B59/00

  Obtaining rare earth metals · CPC title