Method for producing lithium compound and apparatus for producing lithium compound

Patent metadata

Field	Value
Publication number	US-2024182316-A1
Application number	US-202218553099-A
Country	US
Kind code	A1
Filing date	Apr 1, 2022
Priority date	Apr 1, 2021
Publication date	Jun 6, 2024
Grant date	—

Abstract

A method for producing a lithium compound, by which a high purity lithium compound can be produced from low-grade lithium carbonate containing impurities, such as salt water. The method includes: mixing lithium carbonate, an acid containing an organic acid, and water in a reaction tank 1 to produce an aqueous organic acid lithium solution containing an organic acid lithium; mixing the organic acid lithium and a metal hydroxide in a reaction tank 2 to produce an aqueous lithium hydroxide solution; and returning an organic acid, which is regenerated by using an electrochemical device from an organic acid metal by-produced by producing the aqueous lithium hydroxide solution to the reaction tank 1 and using the regenerated organic acid as the organic acid. An apparatus for producing a lithium compound, including the reaction tank 1 , the reaction tank 2 , the electrochemical device, and a return pipe, which each have a specific function.

First claim

1 . A method for producing a lithium compound, comprising:
mixing lithium carbonate, an acid containing an organic acid, and water in a reaction tank 1 to produce an aqueous organic acid lithium solution containing an organic acid lithium, mixing the organic acid lithium and a metal hydroxide in a reaction tank 2 to produce an aqueous lithium hydroxide solution, and returning an organic acid, which is regenerated by using an electrochemical device from an organic acid metal by-produced by producing the aqueous lithium hydroxide solution, to the reaction tank 1 , and using the regenerated organic acid as the organic acid.

2 . The method for producing a lithium compound according to claim 1 , wherein the metal hydroxide is regenerated by the electrochemical device and returned to the reaction tank 2 .

3 . The method for producing a lithium compound according to claim 1 , further comprising:
recovering only lithium ions from the aqueous lithium hydroxide solution into a recovery liquid using a lithium ion separation device equipped with a Li permselective membrane.

4 . The method for producing a lithium compound according to claim 3 , further comprising:
crystallizing the recovery liquid recovered using the lithium ion separation device and performing a solid-liquid separation 1 .

5 . The method for producing a lithium compound according to claim 3 , wherein the organic acid metal is supplied to the electrochemical device by a Li ion-removed aqueous solution obtained by recovering only lithium ions from the aqueous lithium hydroxide solution to the recovery liquid using the lithium ion separation device equipped with a Li permselective membrane.

6 . The method for producing a lithium compound according to claim 1 , further comprising:
adding an oxalic acid to the aqueous organic acid lithium solution and performing a solid-liquid separation 4 .

7 . The method for producing a lithium compound according to claim 6 , wherein the aqueous lithium hydroxide solution is produced by reacting a separated liquid 4 obtained by the solid-liquid separation 4 with the metal hydroxide.

8 . The method for producing a lithium compound according to claim 3 , further comprising:
adding carbon dioxide to the recovery liquid and performing a solid-liquid separation 5 , wherein lithium carbonate contained in a separated liquid 5 obtained by performing the solid-liquid separation 5 is used to produce the aqueous organic acid lithium solution.

9 . The method for producing a lithium compound according to claim 8 , wherein the carbon dioxide is generated by producing the aqueous organic acid lithium solution.

10 . The method for producing a lithium compound according to claim 4 , wherein lithium hydroxide is obtained by performing the solid-liquid separation 1 .

11 . The method for producing a lithium compound according to claim 8 , wherein lithium carbonate is obtained by performing the solid-liquid separation 5 .

12 . The method for producing a lithium compound according to claim 1 , wherein a metal forming the metal hydroxide and a metal forming the organic acid metal are the same.

13 . The method for producing a lithium compound according to claim 1 , wherein the metal is at least one selected from sodium, potassium, and barium.

14 . An apparatus for producing a lithium compound, comprising:
a reaction tank 1 , a reaction tank 2 , an electrochemical device, and a return pipe, wherein the reaction tank 1 is a tank for mixing lithium carbonate, an acid containing an organic acid, and water to produce an aqueous organic acid lithium solution, the reaction tank 2 is a tank for mixing the aqueous organic acid lithium solution and a metal hydroxide to produce an aqueous lithium hydroxide solution, the electrochemical device is a device for regenerating an organic acid, the organic acid is suitable for producing the aqueous organic acid lithium solution from an aqueous solution obtained by removing lithium hydroxide from the aqueous lithium hydroxide solution, and the return pipe is a pipe for returning the regenerated organic acid to the reaction tank 1 .

15 . The apparatus for producing a lithium compound according to claim 14 , further comprising:
a lithium ion separation device equipped with a Li permselective membrane that recovers only lithium ions from the aqueous lithium hydroxide solution into a recovery liquid.

16 . The apparatus for producing a lithium compound according to claim 15 , further comprising:
a crystallization device that crystallizes the recovery liquid.

Assignees

• Idemitsu Kosan Co

Inventors

• Yamamoto Hideki
• Utsuno Futoshi
• Mori Daisuke
• Higuchi Hiroyuki

Classifications

• B01D9/0036

  Crystallisation on to a bed of product crystals; Seeding · CPC title

• B01D9/0031

  by heating (B01D9/0022, B01D9/0027 take precedence) · CPC title

• B01D9/0022

  by reducing pressure · CPC title

• B01D9/0004

  cooling by heat exchange (by evaporation of components of the mixture to be separated B01D9/0013; refrigeration machines F25B) · CPC title

• B01D9/0054

  Use of anti-solvent · CPC title