Method of removing calcium in a rechargeable lithium battery recycling process

Patent metadata

Field	Value
Publication number	US-2025346974-A1
Application number	US-202519199598-A
Country	US
Kind code	A1
Filing date	May 6, 2025
Priority date	May 7, 2024
Publication date	Nov 13, 2025
Grant date	—

Abstract

A method for removing calcium in a lithium battery recycling process includes recovering acidic lithium liquid including calcium; adding an oxalate aqueous solution to the acidic lithium liquid as a first calcium removal process; raising the pH of the acidic lithium liquid to prepare an alkaline lithium liquid; and adding ammonium oxalate to the alkaline lithium liquid as a second calcium removal process.

First claim

What is claimed is:

1 . A method of removing calcium from a lithium liquid from a rechargeable lithium battery recycling process, the method comprising:
recovering acidic lithium liquid including calcium from the recycling process; adding an oxalate aqueous solution to the acidic lithium liquid as a first calcium removal process; raising a pH of the acidic lithium liquid to prepare an alkaline lithium liquid; and adding ammonium oxalate to the alkaline lithium liquid as a second calcium removal process.

2 . The method as claimed in claim 1 , wherein the acidic lithium liquid has pH of about 1 to about 5 before the pH is raised.

3 . The method as claimed in claim 1 , wherein the acidic lithium liquid includes at least one of lithium sulfate and lithium hydrochloride.

4 . The method as claimed in claim 1 , wherein, before the first calcium removal process, the calcium in the acidic lithium liquid is present in an ionic state and the calcium ion is included in an amount of about 1 to about 10,000 ppm.

5 . The method as claimed in claim 1 , wherein the oxalate aqueous solution has a concentration of about 0.1 to about 1 M.

6 . The method as claimed in claim 1 , wherein the first calcium removal process is performed at a temperature range of about 0° C. to about 80° C.

7 . The method as claimed in claim 1 , wherein calcium is precipitated as calcium oxalate in the first calcium removal process.

8 . The method as claimed in claim 1 , wherein at least one of sodium hydroxide and sodium carbonate is used to prepare the alkaline lithium liquid.

9 . The method as claimed in claim 1 , wherein, after the preparing of the alkaline lithium liquid, at least one of iron, magnesium, and zinc is removed.

10 . The method as claimed in claim 1 , wherein the alkaline lithium liquid has a pH of about 7 to about 14.

11 . The method as claimed in claim 1 , wherein the second calcium removal process is performed at a temperature range of about 40° C. to about 100° C.

12 . The method as claimed in claim 1 , wherein calcium is precipitated in a form of calcium oxalate in the second calcium removal process.

13 . The method as claimed in claim 1 , wherein, after the second calcium removal process, the method further includes adding a carbonate ion-containing material or carbon dioxide gas to the alkaline lithium liquid to produce lithium carbonate.

14 . The method as claimed in claim 1 , wherein after the second calcium removal process, the method further includes adding a hydroxide ion-containing material to the alkaline lithium liquid, concentrating, and crystallizing to produce lithium hydroxide.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Yoo Kwangyong
• You Yongchan
• Lee Youngjun
• Park Seongin
• Sohn Myungbeom

Classifications

• H01M10/54 Primary

  Reclaiming serviceable parts of waste accumulators · CPC title

• C01D15/02

  Oxides; Hydroxides · CPC title

• C01D15/08

  Carbonates; Bicarbonates · CPC title

• C22B7/007

  by acid leaching · CPC title

• C22B3/165

  with organic acids · CPC title