Molecular-level chemistry in mineral processing: From quantum mechanics to plant performance

Mineral processing, despite its macroscopic and industrial appearance, is at its most fundamental level a collection of chemical and physical processes occurring at the molecular scale. What manifests in a processing plant as recovery, grade, and throughput is, in reality, the outcome of electronic interactions among mineral surfaces, reagents, and the aqueous phase. In recent decades, remarkable advances in quantum-mechanics-based theoretical methods particularly Density Functional Theory (DFT), molecular dynamics simulations, and multiscale approaches have made it possible to link the macroscopic behavior of industrial equipment to the fundamental characteristics of bonds, electronic structures, and interfacial interactions.

This lecture examines this multiscale connection: from the calculation of band structure and electronic density of states of sulfide and oxide minerals, through the analysis of collector and depressant adsorption mechanisms on mineral surfaces, to the prediction of contact angle, surface hydrophobicity, and ultimately flotation. It is demonstrated how fundamental parameters such as adsorption energy, charge transfer, and dipole moment can be translated into operational indicators such as selectivity, flotation rate, and reagent consumption. Furthermore, the limitations of quantum methods including temporal and spatial scale, solvent and temperature effects, and the complexity of real mineral systems are discussed, and hybrid frameworks that bridge this gap are introduced. Finally, the prospect of employing machine learning and data-driven models as a bridge between precise quantum calculations and real-time industrial process control is outlined. The principal conclusion is that molecular understanding is not an academic luxury, but a strategic tool for designing smarter reagents, optimizing operating conditions, and enhancing the reliability and sustainability of mineral processing.