Adsorption and accumulation mechanism of N2 on groove-type rough surfaces: A molecular simulation study

Flotation is an effective method for mineral separation based on differences in surface physicochemical properties, in which the adsorption and accumulation of gas on the mineral surface is the key process. In this study, molecular dynamics (MD) simulations were employed to clarify the mechanism of adsorption and accumulation of gas on rough surfaces during flotation. A variety of three-phase initial gas-liquid-solid models were constructed by adding grooves of various widths and heights on the base model, which represents the differences in substrate roughness. The results showed that N-2 molecules were adsorbed and accumulated at the bottom of the rough substrate and solid-liquid interface by expelling H2O molecules from the bottom of the groove. Gas adsorption gradually increased with increasing substrate roughness for a set groove width. Meanwhile, the gas molecules were adsorbed and accumulated in the largest amount at the bottom of the medium-roughness substrate when the height was kept fixed because of the limitation of the channel size and the interaction energies between the substrate and N-2 molecules. From the perspective of force, the van der Waals force plays a leading role throughout the entire adsorption process. Revealing the adsorption and accumulation behavior of gas on rough substrates and the effect of substrates with various roughness values on gas adsorption, which will help to strengthen the understanding of the gas-liquid-solid interaction mechanism in the flotation process. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study employed molecular dynamics simulations to clarify the mechanism of adsorption and accumulation of gas on rough surfaces during flotation, revealing that van der Waals force plays a leading role throughout the entire adsorption process. The findings contribute to a better understanding of the gas-liquid-solid interaction mechanism in the flotation process.