Recovery of lithium from coal gangue utilizing acid baking followed by water leaching

ABSTRACT

With the rapid development of the lithium (Li)-ion battery industry in electric vehicles (EVs) and electronic devices, coal-based Li ore is expected to be a new-type Li resource to meet the rapidly growing demand for Li. However, the traditional Li extraction process involves high temperature to activate minerals. Herein, a low-temperature sulfuric acid baking followed by water leaching was investigated in this study. The influences of baking and leaching conditions on Li leaching rate were explored in detail. Under the optimal conditions of 70 wt% H₂SO₄, baking temperature 180°C, baking time 1 h, leaching temperature 25°C, and leaching time 1 h, the Li leaching rate reached 84.42%. In addition, the sequential chemical extraction, XRD, and SEM-EDS results indicated that Al-Li-containing minerals were converted to soluble minerals during the baking process with sulfuric acid and then were extracted through water leaching into the solution.

KEYWORDS:

• Coal gangue
• lithium
• sulfuric acid baking
• water leaching

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Credit authorship contribution statement

Yu Xie: Validation, Writing – Original Draft. Chenquan Ni: Validation, Investigation, Data Curation. Zhengwei Han: Validation, Investigation. Jialong Liao: Validation, Investigation. Weiqi Xie: Review & Editing. Hui Zhong: Conceptualization, Writing – Review & Editing. Zhiguo He: Conceptualization, Writing, Review & Editing, Supervision, Funding acquisition.

Additional information

Funding

The authors gratefully acknowledge the financial support of the National Key Research & Development Project of China (No.2021YFC2903203-02), Research on Key Technologies of Exploration and Development of Coal-serial Mineral Resources (ZMKJ-2021-ZX03).