Large system study of chalcopyrite and pyrite flotation surfaces based on SCC-DFTB parameterization method

In recent years, the study of chalcopyrite and pyrite flotation surfaces using computational chemistry methods has made significant progress. However, current computational methods are limited by the small size of their systems and insufficient consideration of hydration and temperature effects, making it difficult to fully replicate the real flotation environment of chalcopyrite and pyrite. In this study, we employed the self-consistent charge density functional tight-binding (SCC-DFTB) parameterization method to develop a parameter set, CuFeOrg, which includes the interactions between Cu-Fe-C-H-O-N-S-P-Zn elements, to investigate the surface interactions in large-scale flotation systems of chalcopyrite and pyrite. The results of bulk modulus, atomic displacement, band structure, surface relaxation, surface Mulliken charge distribution, and adsorption tests of typical flotation reagents on mineral surfaces demonstrate that CuFeOrg achieves DFT-level accuracy while significantly outperforming DFT in computational efficiency. By constructing large-scale hydration systems of mineral surfaces, as well as large-scale systems incorporating the combined interactions of mineral surfaces, flotation reagents, and hydration, we more realistically reproduce the actual flotation environment. Furthermore, the dynamic analysis results are consistent with mineral surface contact angle experiments. Additionally, CuFeOrg lays the foundation for future studies of more complex and diverse chalcopyrite and pyrite flotation surface systems.