Flotation behavior and mechanism of calcium carbonate polymorphs with sodium oleate as collector

Flotation behavior of calcite and aragonite with a sodium oleate collector was studied. The mechanism for the difference in flotation recovery and kinetics of the two minerals was analyzed via adsorption quantity, microcalorimetry, flotation diffraction method, and calculation of unsaturated bond density on mineral exposed planes. Results showed that the flotation recovery and rate of aragonite was higher than those of calcite. The adsorption quantity and rate of sodium oleate on the surface of aragonite was higher than that with calcite. The adsorption heat of sodium oleate with aragonite was higher than calcite, The order of the unsaturated bond densities of calcium points on the exposed planes of calcite and aragonite were (012) calcite > (018) calcite > (104) calcite > (020) aragonite > (111) aragonite > (220) aragonite. The unsaturated bond density of calcium points on the exposed planes of aragonite were less than those of the calcite exposed planes. Sodium oleate could more easily overcome water molecules when it interacted with aragonite. Thus, the flotation recovery and rate of aragonite was higher than that of calcite. • The flotation recovery and kinetics of aragonite was higher than that of calcite. • Crystal plane of calcite and aragonite show orientation effects in flotation process. • Different flotation behaviors were explained by surface active sites of Ca atoms.