Lithium extraction from typical lithium silicate ores by two bacteria with different metabolic characteristics: Experiments, mechanism and significance

Xingqing Zhao; Yucheng Zhou; Congcong Ding; Xiaopeng Wang; Xinyi Zhang; Rucheng Wang; Xiancai Lu

doi:10.1016/j.jenvman.2023.119082

Lithium extraction from typical lithium silicate ores by two bacteria with different metabolic characteristics: Experiments, mechanism and significance

J Environ Manage. 2023 Dec 1:347:119082. doi: 10.1016/j.jenvman.2023.119082. Epub 2023 Sep 30.

Authors

Xingqing Zhao¹, Yucheng Zhou², Congcong Ding², Xiaopeng Wang², Xinyi Zhang², Rucheng Wang³, Xiancai Lu³

Affiliations

¹ School of Environmental Science and Engineering, Changzhou University, Changzhou, 213164, PR China. Electronic address: zhaoxq@cczu.edu.cn.
² School of Environmental Science and Engineering, Changzhou University, Changzhou, 213164, PR China.
³ State Key Laboratory for Mineral Deposit Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, PR China.

PMID: 37783078
DOI: 10.1016/j.jenvman.2023.119082

Abstract

Microorganisms obtain inorganic nutrients or energy from specific minerals to selectively weather minerals, but few studies on the differences in metabolic components of different functional bacteria lead to different weathering effects. This study evaluated the leaching effects of two bacteria with distinct metabolic characteristics on lithium silicate minerals with different structures. We aimed to understand the microscopic mechanism of crystal destruction of lithium silicate minerals with different structures under the action of microorganisms. The results showed that the metabolites produced by an acid producing silicate strain Raoultella sp. Z107 (strain Z107) had a high content of organic acids, among which lactic acid was up to about 11 g/L. Bacillus mucilaginosus 21,699 (strain BM) secreted capsular polysaccharide with a high content of 14.84 mg/L. The metabolic activities of the two strains were significantly different. Through the analysis of the leaching residue, it was found that the lithium silicate minerals were acid etched, interlayer domains expanded, crystallinity decreased, and metal bonds were broken under the action of bacteria. The dissolution of lithium silicate minerals by bacteria is a combination of bacterial adsorption, organic acid corrosion, and complexation of small molecular organic acids and macromolecular polymers with metal ions. The acid erosion and complexation effects of organic acids are greater than the single complexation of capsular polysaccharides, and the layered lepidolite is more likely to be decomposed by the weathering of bacterial metabolites than the chain structure spodumene. These results indicate that the diversity of metabolic activity of bacteria from different sources and the sequence and decomposition mechanism of metal ions released from minerals after lattice destruction are also different. Microorganisms decompose minerals for energy and nutrients, and eventually become the main players in the transformation of elements in biogeology.

Keywords: Lithium; Metabolites; Microbial bioleaching; Resource utilization; Silicate ore.

MeSH terms

Ions
Lithium*
Minerals / analysis
Minerals / chemistry
Minerals / metabolism
Organic Chemicals
Silicates* / chemistry
Silicates* / metabolism

Substances

Lithium
Silicates
Minerals
Ions
Organic Chemicals