Mechanism of molecular Synergy in the Aerophine 3418A-DTP mixed Collector: Insights into hydrophobicity and non-polar group interactions for chalcopyrite flotation

To investigate the synergistic enhancement mechanism of the 3418A-DTP mixed collector in the flotation process of chalcopyrite, multiscale analytical methods of atomic force microscopy (AFM), first-principles molecular dynamics (MD), and scanning electron microscopy/energy-dispersive spectroscopy (SEM-EDS) were adopted to systematically explore the molecular mechanism of hydrophobicity enhancement and interactions between the non-polar groups of the collector. The AFM bubble probe technology revealed that the adsorption of the mixed collector increased the density of hydrophobic points on the mineral surface by 35.4%, reaching the maximum hydrophobic area and effectively improving the adhesion between bubbles and minerals. Theoretical calculations further confirmed that the interaction force between the non-polar groups of the 3418A-DTP mixed collector was strengthened, leading to notable hydrophobicity enhancement. It was observed from first-principles calculations that the tightly arranged non-polar functional groups of the collector formed a dense hydrophobic layer on the mineral surface to block water permeation. It was noticed from classical MD simulations that the contact angle of the mixed collector after adsorption increased by 6.2–7.0° compared to that of a single collector, confirming the synergistic strengthening effect.