The role of the solution chemistry of dodecylamine and oleic acid collectors in the flotation of fluorite

Abstract

Solution chemistry and flotation studies were made of dodecylamine and oleic acid collectors with fluorite particles. From solution equilibria diagrams, the surface tension, electrophoretic mobility and particle—particle interactions could be correlated to the adsorption of amphiphiles at the mineral solution interface. The high flotation response was found to occur over narrow pH ranges which appeared to be characteristic of the amine and oleate collector systems. This was explained by the synergistic co-adsorption of a mixture of collector species at the interfacial regions. It was suggested that this could lead to the formation of a mixed hemi-micelle structure producing a hydrophobic coating at the solid/liquid (S/L) interface and a maximum in surface pressure at the liquid/gas (L/G) interface. Although the exact structure and composition of the interfacial regions could not be determined, it was thought to involve ion—molecular complexes co-adsorbed with possibly monomer, dimer and molecular precipitated and solubilized surfactant species.