Metal recovery apparatus and metal recovery method

Patent metadata

Field	Value
Publication number	US-2024344168-A1
Application number	US-202218294199-A
Country	US
Kind code	A1
Filing date	Aug 4, 2022
Priority date	Aug 4, 2021
Publication date	Oct 17, 2024
Grant date	—

Abstract

A metal recovery apparatus including a leaching unit that directly leaches a metal element contained in a composition into a hydrophobic deep eutectic solvent and a recovery unit that separates and recovers the metal element from the deep eutectic solvent, wherein the metal element-containing composition is solid at 25° C. and does not contain an inorganic acid, the metal element is a metal, a metal compound, or metal ions, and the deep eutectic solvent does not contain an inorganic acid.

First claim

1 . A metal recovery apparatus comprising
a leaching unit that directly leaches at least one metal component contained in a metal element-containing composition into a hydrophobic deep eutectic solvent, and a recovery unit that separates and recovers the metal component from the deep eutectic solvent, wherein the metal element-containing composition is solid at 25° C. and does not contain an inorganic acid, the metal component is a metal, a metal compound, or metal ions, and the deep eutectic solvent does not contain an inorganic acid.

2 . The metal recovery apparatus according to claim 1 , wherein the deep eutectic solvent has hydrophobicity of 1 g/100 mL or less in terms of solubility in water at 25° C.

3 . The metal recovery apparatus according to claim 1 , wherein the deep eutectic solvent does not contain an organic solvent having a boiling point of 150° C. or lower alone.

4 . The metal recovery apparatus according to claim 1 , wherein extraction of moving the metal component from the deep eutectic solvent to another organic solvent is not performed between the leaching unit and the recovery unit.

5 . The metal recovery apparatus according to claim 1 , wherein the deep eutectic solvent is a liquid at 25° C.

6 . The metal recovery apparatus according to claim 1 , wherein the metal element-containing composition contains two or more types of the metal components,
the deep eutectic solvent selectively leaches a specific type of metal component among the two or more types of metal components at a higher concentration than other types of metal components.

7 . The metal recovery apparatus according to claim 1 , wherein the deep eutectic solvent is a mixture of a hydrogen bond donor and a hydrogen bond acceptor,
at 25° C., the hydrogen bond donor and the hydrogen bond acceptor before mixing are in a form of solid particles, the metal component is brought into contact with the deep eutectic solvent by directly contacting the solid particulate hydrogen bond donor and hydrogen bond acceptor with the metal element-containing composition.

8 . The metal recovery apparatus according to claim 1 , wherein the deep eutectic solvent is a mixture of a hydrogen bond donor and a hydrogen bond acceptor,
the hydrogen bond donor is benzoyltrifluoroacetone or a decanoic acid, and the hydrogen bond acceptor is tri-n-octylphosphine oxide.

9 . The metal recovery apparatus according to claim 1 , wherein the deep eutectic solvent is a mixture of a hydrogen bond donor and a hydrogen bond acceptor,
the hydrogen bond donor has a concentration controlled to be 1.2 to 5 times the concentration of the hydrogen bond acceptor.

10 . The metal recovery apparatus according to claim 1 , wherein the metal element-containing composition contains a metal oxide, and
a reducing agent is further added to the deep eutectic solvent.

11 . The metal recovery apparatus according to claim 10 , wherein the reducing agent is an L-ascorbic acid, a citric acid, or a malic acid.

12 . The metal recovery apparatus according to claim 10 , wherein the reducing agent has a concentration controlled to 0.03 to 0.30 mol/L with respect to the deep eutectic solvent.

13 . The metal recovery apparatus according to claim 10 , wherein the metal element-containing composition contains LiCoO 2 or LiNi 1/3 Mn 1/3 Co 1/3 O 2 .

14 . The metal recovery apparatus according to claim 1 , wherein the metal element-containing composition contains a platinum group metal or a platinum group metal compound, and
an oxidizing agent is further added to the deep eutectic solvent.

15 . The metal recovery apparatus according to claim 1 , wherein the deep eutectic solvent has a water content controlled to 0.3 to 2.8% by mass.

16 . The metal recovery apparatus according to claim 1 , wherein the recovery unit brings a hydrophilic solvent into contact with the deep eutectic solvent to separate and recover the metal component in the hydrophilic solvent.

17 . The metal recovery apparatus according to claim 16 , wherein a chelating agent is added to the hydrophilic solvent, and the metal component is precipitated as a salt in the hydrophilic solvent to be separated and recovered.

18 . The metal recovery apparatus according to claim 1 , further including a recycle unit that returns the deep eutectic solvent from which the metal component has been separated in the recovery unit to the leaching unit to recycle.

19 . The metal recovery apparatus according to claim 18 , wherein the recycle unit cleans the deep eutectic solvent using a cleaning liquid that is capable of removing the chelating agent.

20 . The metal recovery apparatus according to claim 18 , wherein, when a cycle of the leaching unit, the recovery unit, and the recycle unit is repeated three times using only the deep eutectic solvent returned by the recycle unit in the leaching unit, the metal component has a leaching rate expressed by the following formula 1 of 80% or more, and the metal component has a recovery rate expressed by the following formula 2 of 95% or more,

%
⁢

L

=

C

M
,
DES

×

V
DES

m
init

m

×
100

Formula
⁢

1

in the formula 1, % L represents the leaching rate, C M,DES represents a concentration of the metal component in the deep eutectic solvent, V DES represents a volume of the deep eutectic solvent, m init represents a mass of the metal element-containing composition, and m represents a molecular weight of the metal element-containing composition,

%
⁢

S

=

C

M
,
S
,
DES

×

V

Assignees

• Univ Kyushu Nat Univ Corp
• Prime Planet Energy & Solutions Inc
• Toyota Tsusho Corp
• Toyota Motor Co Ltd

Inventors

• Goto Masahiro
• Hanada Takafumi

Classifications

• C22B3/26

  by liquid-liquid extraction using organic compounds · CPC title

• C22B3/06

  in inorganic acid solutions {, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions} · CPC title

• C22B7/006

  Wet processes · CPC title

• C22B23/00

  Obtaining nickel or cobalt · CPC title

• C22B3/165

  with organic acids · CPC title