A novel insight of interaction mechanism of carboxymethyl cellulose with talc surface: A combined molecular dynamic simulation and DFT investigation

Separation of talc from sulfide minerals through adding depressor in flotation field is very necessary, while the interaction of depressor on the surface of talc still needs to be further explained. Here, a typical depressor, carboxymethyl cellulose (CMC), interacted with talc surface was deeply investigated from atomic structure and surface hydration though molecular dynamic simulation (MDs) and density functional theory (DFT) calculation. MDs was applied on investigating adsorption behaviors of CMC on basal and edge plane of talc in aqueous solutions, and DFT was used for studying the interacted orbitals and charge transfer. It was found that adsorption of CMC on surface of edge plane was stronger than that on the surface of basal plane due to the enhanced interaction of polar group on the edge plane and the dragged water molecules. Interactions existed between H atoms in CMC and O atoms in edge plane, between O atoms in CMC and Si, Mg atoms in edge plane. The strong interacted water molecules dragged CMC close to the surface, thus to strengthen the binding of CMC and edge plane of talc. Furthermore, the hydration shell on the basal and edge plane of talc was investigated for explaining the phenomenon. Therefore, our work gave a new insight into the microscopic interaction between talc and CMC, thus to guide the actual application.