Mechanisms for the improved flotation of inherently hydrophobic graphite in electrolyte solution

It is well documented that unavoidable ions in a pulp such as Mg2+, Ca2+, and K+ have a significant effect on the interaction for particles, especially for flotation of metallic sulfide minerals and clay minerals. In this study, the effect of electrolytes on the flotation of inherently hydrophobic mineral-graphite was studied. It was found that the zeta potential showed a dramatic decrease, and the reagent adsorption capacity of mineral enhanced in the present of electrolytes. The possible mechanism responsible for improved recovery was investigated by electrokinetic, surface tension and ions adsorption tests. It is likely that the hydrophobic force is stronger than the electrostatic force due to the reduced potential of graphite. This might be in favor of the formation of hydrophobic oil film leading to an increase in the graphite floatability. The experiments provided a new spectacle to study inherently hydrophobic mineral processing with electrolyte solution.