2025 AIChE Annual Meeting

(588bx) Computational Techniques for Probing Metal-Ligand Interactions and Enhanced Forth Flotation Ligand Design

Over the coming decades global and domestic critical mineral production must increase dramatically. This is exemplified by the challenge of copper production, which must increase from roughly 30 Mt/year today to 50 Mt/year by 2035, with more than 80% coming from mined ores, to meet increasing demand brought on by rising global populations, industrialization, and the renewable energy transition1,2. Froth flotation is the most widely used method for separating and concentrating the majority of (60 out of 79) stable, non-radioactive and naturally occurring elements, especially all the chalcophiles (Cu, Ni, Co, PGM, etc.) in the Periodic Table. 3 In the flotation separation process for chalcophile minerals, several families of bifunctional short-chain organic S-based ligands are used widely. These ligands selectively adsorb on the desired value minerals and make the surfaces hydrophobic to facilitate attachment to bubbles, which is necessary for flotation. However, conventional ligands have several significant drawbacks, including an inability to cope with ores of increasing complexity, low value content, variability, and heterogeneity, to facilitate the recovery of coarse and fine value particles. There have been minimal academic or industrial research efforts towards understanding ligand-mineral interactions towards the rational design of ligands. This has created a critical need for novel selective high-performance ligands. However, ligand design and development are hampered by major challenges including inadequate and fragmented design principles, high experimental costs for ligand development and lack of tools to asses ligand-mineral interactions.3,4

In this work, we employ computational techniques including data science and COSMO-RS (COnductor-like Screening MOdel for Realistic Solvents) towards the rationale design of new ligand chemistries. We compile a foundation database of commercial ligands and analogous chemistries to develop new tools and insights surrounding ligand structure-property relationships. Furthermore, we employ COSMO-RS calculations combing electrostatic theory for locally interacting molecular surface descriptors with statistical thermodynamics to calculate ligand surface interactions and equilibrium behavior to extract key insights into ligand-mineral behavior. This work marks a new approach towards streamlining and accelerating ligand design and development for critical minerals separation and extraction.

References

(1) Global, S. The Future of Copper.; 2022.

(2) Guj, P.; Schodde, R. Will Future Copper Resources and Supply Be Adequate to Meet the Net Zero Emission Goal? Geosystems and Geoenvironment 2024, 4, 100320.

(3) Nagaraj, D. R., R. Farinato, E. Arinaitwe, Flotation chemicals and chemistry, SME Mineral processing and extractive metallurgy handbook, Society for Mining, Metallurgy & Exploration Englewood, Colorado2019, pp. 967-1010.

(4) Nagaraj, D. R.; Farinato, R. S. Evolution of Flotation Chemistry and Chemicals: A Century of Innovations and the Lingering Challenges. Miner. Eng. 2016, 96–97, 2–14.