Comparative Crystal Properties of Fluorite and Dolomite: Implications for Flotation Reagent Design

This study systematically compares the crystal properties of fluorite (CaF₂) and dolomite [CaMg(CO₃)₂] through first-principle calculations. Density functional theory (DFT) simulations revealed fundamental differences in structural and electronic characteristics: fluorite exhibits purely ionic Ca-F bonds (Mulliken population: 0.08) with a wide bandgap; whereas dolomite demonstrates a hybrid bonding nature featuring ionic Ca-O/Mg-O bonds (populations: 0.09/0.18) and covalent C-O bonds (0.86), which are accompanied by a narrower bandgap. The charge density and density of states (DOS) analyses demonstrated fluorine's dominant electronic reactivity in fluorite (F 2p states near Fermi level) versus the oxygen/calcium activity in dolomite. Cleavage studies identify preferential fracture planes, with fluorite's {111} plane exhibiting higher unsaturated bond density (14.76 nm^-1) than dolomite's {104} plane (10.55 nm^-1), which correlates with their distinct mechanical processing behaviors. This work establishes a theoretical foundation for developing selective separation strategies by exploiting crystal-specific surface properties.