Electrokinetic transport mechanisms of rare earth elements in ion-adsorption deposits: An integrated model approach
Year: 2025
Type: article
Abstract: Heavy rare earth elements (REEs) are critical strategic resources for advanced technologies and low-carbon economy transition. Ion-adsorption deposits (IADs) represent the primary sources of heavy REEs, yet their mining has caused severe environmental impacts. Electrokinetic mining (EKM), a sustainable alternative, promises efficient REE recovery from IADs. However, the electrokinetic transport mechanisms of REEs in IADs remain unclear, and predictive models are lacking. Here, we develop an integrated EKM (IEKM) model that rigorously incorporates coupled effects of diffusion, convection, electromigration, electroosmosis, and electrolysis, to resolve REE transport in IADs. The IEKM model was validated using a 14-ton-scale IAD EKM, accurately simulating REE and leaching agent (NH₄⁺) ion transport. The predicted REE recovery efficiency is 80.97% after 11 days of EKM, aligning with experimental results (88.28±17.00%). Significantly, the IEKM model quantitatively determines that diffusion, convection, electromigration, electroosmosis, and electrolysis contribute 3.06%, 2.90%, 82.91%, 0.20%, and 10.93%, respectively, to REE transport. Unexpectedly, electromigration emerges as the dominant mechanism governing REE electrokinetic transport in IADs with significant influence by electrolysis, while electroosmosis exhibits negligible contribution contradicting conventional expectations. Furthermore, electrolysis consumed 57.95% of input energy due to water splitting, leaving only 42.05% for direct REE transport. This work advances fundamental understanding of REE electrokinetic transport in IADs and establishes an industrially viable model, bridging experimental and numerical modeling to facilitate practical applications of environmentally sustainable EKM technology in resource recovery.
Authors: Jie Xu, Gaofeng Wang, Bowen Ling, Shichang Kang, Yongqiang Yang, Xiaoliang Liang, Jingming Wei, Yongjin Xu, Jianxi Zhu, Hongping He
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,930
Funders: National Natural Science Foundation of China, Chinese Academy of Sciences, Guangdong Science and Technology Department, Guangzhou Science and Technology Program key projects, Science and Technology Planning Project of Guangdong Province, National Major Science and Technology Projects of China, Basic and Applied Basic Research Foundation of Guangdong Province
OpenAlex ID: W4410487146