Comparison of NaOL Adsorption on the Hematite 001 Surface with Water Molecules Adsorption on the Hydrophilic Hematite Surface Using Molecular Dynamics Simulation

This article reports on a molecular dynamics simulation-based research that investigates the adsorption of sodium oleate (NaOl) on the of the highly hydrophilic 001 hematite surface in froth flotation and its effect on the mineral's wettability properties. The molecular dynamics simulation was conducted using LAMMPS. The wettability properties were evaluated by comparing the thermodynamic characteristics of two surfaces, one net and the other coated by the collector. Surface energy, center of mass location of water molecules, water density in contact layers and adjacent to the surface, and fluid permeability coefficient were used as indicators of wettability. The simulation results showed that the 001 surface of hematite is highly hydrophilic due to strong electrostatic interactions and feasible hydrogen bond formation sites. However, with the adsorption of the collector, the surface became hydrophobic due to a sharp decrease in surface tension, reduction of intermolecular interactions, and loss of hydrogen bond formation sites. The results confirm that the selective absorption of the collector on the hematite surface enables its floatability.