The urgent need for scalable CO₂ removal technologies, combined with growing demand for critical metals, has driven interest in mine tailings as a dual resource for permanent carbon storage and metal recovery. Mafic and ultramafic tailings are rich in Ca‑ and Mg‑bearing silicates suitable for mineral carbonation, while also hosting economically valuable metals such as nickel and cobalt. Integrating these processes in a single, low‑emission workflow requires selective ligands that promote Ni and Co mobilisation without inhibiting carbonate formation of major gangue elements.
In this work, we present a molecular‑scale framework for guiding ligand selection and process optimisation for integrated mineral carbonation and critical metal recovery. We began with ab initio molecular simulations of EDTA, NTA, and citric acid and compared to experimental results to validate the modelling approach, and then extended the calculations to environmentally benign ligands such as IDS, GLDA, and glycine to assess metal selectivity under carbonation‑relevant conditions.
The modelling results provide mechanistic insight into how ligand strength and coordination geometry influence both metal recovery efficiency and carbonate precipitation pathways. By identifying ligands with sufficient affinity for target metals yet weak interaction with major silicate‑derived cations, this approach enables rational pre‑screening of reagents prior to experimental testing. The outcomes inform optimal reaction windows in temperature, pressure, pH, and chemical composition, significantly reducing experimental trial‑and‑error.
This study demonstrates how molecular modelling can accelerate the development of integrated carbonation–recovery processes, delivering both environmental and economic benefits. The framework supports cost‑effective reagent selection, improved process efficiency, and scalable deployment for sustainable mineral processing and ex-situ mineral carbonation.