Flotation Chemistry of Hematite/oleate System

Oleate flotation characteristics of hematite have been investigated in thjs study under a wide range of experimental conditions of pH, temperature, ionic strength and collector concentration. The study revealed the following major features of this system which include: (a) a maximum in floatability in the neutral pH range; (b) an increase in the flotation response of hematite with increase either in solution ionic strength at room tempera ture or in temperature at low ionic strengths; (c) marked temperature-ionic strength interactions yielding an inversion of the above effect under elevated temperature and high ionic strength conditions. None of these features can be satisfactorily explained by classical theories of collector adsorption based on electrostatic or chemisorption model. In this paper, the flotation results are explained taking the adsorption kinetics and the solution chemistry of the oleate into consideration. It is shown that the unique solubility characteristics of oleate, together with its tendency to form ionomolecular complexes, is largely responsible for the observed complex flotation behavior.