The Interaction between Ca2+ and Molybdenite Edges and Its Effect on Molybdenum Flotation

In this paper, the influence of Ca2+ on the flotation of a skarn type molybdenum ore and pure molybdenite mineral at pH 8 was studied using diesel as the collector. It was found that Ca2+ had little effect on molybdenum flotation at low concentrations. By further increasing Ca2+ concentration, the floatability of molybdenite—especially from the fine size fractions—was depressed even without the presence of fine gangue minerals. The mechanism responsible for the deleterious effect of Ca2+ on molybdenite flotation was studied by a range of techniques including zeta potential measurements, Scanning Electron Microscopy, and Energy Dispersive X-ray Spectrometer (SEM-EDS) analyses and molybdenum phase analyses. It was found that Ca2+ interacted with molybdenite edges producing CaMoO4 precipitates which were responsible for the depression of molybdenite flotation of Ca2+ by preventing the adsorption of diesel.