Collectability and Selectivity of Flotation Agent

The hydrophobic property generated by chemisorbed agent influences selectivity of flotation but not always governs recovery of minerals. It is suggested to evaluate efficiency of a chemisorbed agent by two criteria. First, free surface energy reduction at the moment of local rupture of the liquid interlayer between particle and bubble. Second, displacement of the contact perimeter of three physical states of particle surface under the action of surface forces at their interface. It is found that physisorption conditions collectability of a flotation agent and recovery of a target mineral in concentrate. A physisorbed collector removes liquid from the particle-bubble interlayer. The definition of the physisorbed collector force is given and its essentiality is proved. The physisorbed collector force is effective at the gas-liquid interface rather than mineral-liquid interface, and is not selective. Selectivity of an agent is governed by the chemisorptions/physisorption activity ratio of a flotation agent.