Structure-activity relationships in lithium-hosting montmorillonite: Octahedral lithium locking mechanisms--颗粒学报PARTICUOLOGY

a Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, China
b State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, China
c City College, Kunming University of Science and Technology, Kunming 650051, China

10.1016/j.partic.2025.06.001

Volume 104, September 2025, Pages 42-51

Received 2 April 2025, Revised 27 May 2025, Accepted 1 June 2025, Available online 13 June 2025, Version of Record 25 June 2025.

E-mail: Jianliu@kust.edu.cn; 20140045@kust.edu.cn

Highlights

• Dual structural-charge locking mechanism of lithium in octahedral is elucidated.

• Various occurrence sites of lithium in montmorillonite are compared by density functional theory.

• Effects of lithium occurrence sites in montmorillonite on interfacial properties are expounded.

Abstract

The structural complexity of lithium-bearing clay minerals and limitations of conventional characterization methods impede efficient lithium extraction from montmorillonite-type ores. This study employs density functional theory to elucidate structure-activity relationships governing lithium occurrence in montmorillonite, with particular emphasis on octahedral locking mechanisms and interfacial reaction barriers. Systematic calculations reveal four potential lithium occurrence sites: Al-O octahedra, Si-O tetrahedral lattices, interlayer sites and Li substituted H site. Lithium demonstrates optimal stability within Mg-Al-O octahedral lattices, exhibiting the lowest interaction energy (−672.982 kJ/mol) and substantial Mulliken charge transfer (2.35 e), confirming this configuration as the primary hosting environment. Density of states analysis uncovers critical electronic structure features: the 1s orbital of lithium remains energetically isolated from the Fermi level, explaining its chemical inertness and resistance to direct leaching. Conversely, the reactive 2p orbital of oxygen near the Fermi level facilitate surface interactions with flotation reagents. These electronic signatures imply the feasibility of flotation recovery alongside hydrometallurgical approaches. The octahedral locking mechanism originates from Li-induced dynamic symmetry reconstruction. This process achieves energy minimization through bond-angle regularization, while the notable contraction of Al-O/Mg-O bonds enhances electrostatic coupling. These synergistic effects ultimately establish a structural-charge dual-locking mechanism. This study delivers atomic-level insights into lithium occurrence mechanisms, addressing critical gaps in clay-type lithium mineralogy and revealing structure-activity relationships that guide sustainable lithium recovery via interface regulation.

Graphical abstract

Keywords

Structure-activity relationships; Clay-type lithium mineral; Montmorillonite; Occurrence sites; Al-O octahedra

文章导读