Method for extracting lithium from waste lithium battery

Patent metadata

Field	Value
Publication number	US-2024088468-A1
Application number	US-202218555262-A
Country	US
Kind code	A1
Filing date	May 12, 2022
Priority date	Sep 6, 2021
Publication date	Mar 14, 2024
Grant date	—

Abstract

The present disclosure discloses a method for extracting lithium from waste lithium batteries, which comprises: leaching positive electrode powder of the waste lithium battery in hydrochloric acid, and obtaining leaching solution by filtering; removing copper and iron from the leaching solution, and then introducing hydrogen sulfide gas for reaction, and performing solid-liquid separation to obtain first filter residue and first filtrate; adding potassium permanganate to the first filtrate, and performing solid-liquid separation to obtain second filter residue and second filtrate; performing spray pyrolysis on the second filtrate to obtain solid particles and tail gas, washing the solid particles with water to obtain a lotion, washing and collecting the tail gas and then mixing the tail gas with the lotion to obtain lithium salt solution. In the present disclosure, the positive electrode powder is leached with hydrochloric acid to obtain the hydrochloric acid leaching solution, and hydrogen sulfide is used to precipitate nickel and cobalt after removing the copper and iron impurities in the leaching solution in turn, and potassium permanganate is added to precipitate manganese ions to generate manganese dioxide. Spray pyrolysis converts the aluminum and magnesium in the solution into oxides and lithium salt is separated. The entire reaction process does not require organic solvent extraction and reduces the loss of lithium.

First claim

1 . A method for extracting lithium from waste lithium batteries, comprising the following steps:
S1: leaching positive electrode powder of the waste lithium batteries in hydrochloric acid, and obtaining leaching solution by filtering; S2: removing copper and iron from the leaching solution, and then introducing hydrogen sulfide gas for reaction, and performing solid-liquid separation to obtain first filter residue and first filtrate; S3: adding potassium permanganate to the first filtrate, and performing solid-liquid separation to obtain second filter residue and second filtrate; S4: performing spray pyrolysis on the second filtrate to obtain solid particles and tail gas, washing the solid particles with water to obtain a solution, washing and collecting the tail gas and then mixing the tail gas with the solution to obtain lithium salt solution.

2 . The method according to claim 1 , wherein in step S1, concentration of the hydrochloric acid is 1.0-6.0 mol/L, and solid-liquid ratio of the positive electrode powder to the hydrochloric acid is 100-250 g/L.

3 . The method according to claim 1 , wherein in step S2, the process of removing copper and iron is: adding iron powder to the leaching solution to perform a displacement reaction, adding an oxidizing agent and adjusting pH to 3.5-4.0 after the reaction is completed, performing solid-liquid separation to remove copper and iron residue.

4 . The method according to claim 3 , wherein in step S2, molar ratio of the amount of iron powder added to content of copper ion in the leaching solution is (1.0-1.1):1.

5 . The method according to claim 3 , wherein in step S2, calcium carbonate is used to adjust pH.

6 . The method according to claim 1 , wherein in step S2, pressure of the hydrogen sulfide is 200-300 kPa; preferably, the reaction temperature of hydrogen sulfide gas introduced is 65-125° C.

7 . The method according to claim 1 , wherein in step S2, the first filter residue is nickel cobalt sulfide precipitate, and the nickel cobalt sulfide precipitate is dissolved in sulfuric acid to obtain nickel sulfate and cobalt sulfate solution.

8 . The method according to claim 1 , wherein in step S3, the potassium permanganate is added by titration until no more precipitation occurs.

9 . The method according to claim 1 , wherein in step S4, spray pyrolysis temperature is 600-1350° C., and carrier gas pressure is 0.1-0.3 MPa.

10 . The method according to claim 1 , wherein in step S4, adding carbonate to the lithium salt solution for reaction to obtain lithium carbonate precipitate; preferably, temperature of the reaction is 80-95° C.

Assignees

• Guangdong Brunp Recycling Technology Co Ltd
• Hunan Brunp Recycling Tech Co Ltd
• Hunan Brunp Ev Recycling Co Ltd

Inventors

• Yu Haijun
• Xie Yinghao
• Li Aixia
• Zhang Xuemei
• Li Changdong

Classifications

• Y02W30/84

  Recycling of batteries or fuel cells · CPC title

• Y02P10/20

  Recycling · CPC title

• H01M10/54 Primary

  Reclaiming serviceable parts of waste accumulators · CPC title

• C22B7/007 Primary

  by acid leaching · CPC title

• C22B26/12 Primary

  Obtaining lithium · CPC title