A coarse-grained simulation insight of the adsorption process of mixed collector at low-rank coal/water interface

Low-rank coal upgrading poses significant challenges, and conventional collectors like kerosene and diesel exhibit suboptimal performance. While mixed collectors have shown improved flotation outcomes, their interaction mechanism with low-rank coal remains poorly understood. Molecular simulation methods have limitations in studying this mechanism due to the simplified representation of coal models and the neglect of simultaneous adsorption competition among different functional groups. Additionally, All-Atom molecular dynamics (AAMD) simulation suffers from high collector concentrations and pre-placement near the coal surface, hindering the observation of dynamic adsorption processes. To address these limitations, this study employs the Coarse-Grained molecular dynamics (CGMD) method, which closely approximates the actual collector usage in flotation. By utilising a comprehensive low-rank coal classic model, we investigate the dynamic adsorption process, equilibrium adsorption configuration, optimal adsorption site, coal-collector interaction energy, and induced adsorption process between collectors. The CGMD method offers valuable insights into the compounding mechanism of mixed collectors and serves as a theoretical reference for collector mixing.