Surface Chemical Characteristics and Adsorption Properties of Calcite as One of the Gangue Minerals of Phosphate Ores

摘要

The poor selectivity in carbonaceous phosphate beneficiation in aqueous medium has been attributed to the similarities in the surface chemical properties between the carbonate and phosphate minerals. The success of beneficiation processes such as flocculation and flotation depends to a large extent on the surface charge characteristics of the minerals involved. Interfacial behavior of sparingly soluble minerals such as apatite and calcite is governed to a large extent by its electrochemical properties. Dissolved ionic species, pH and kinetics of adsorption can determine the surface charge. Adsorption of surfactants on all the phosphate carbonate minerals is dependent on the interfa-cial characteristics. In this paper electrokinetic properties of natural pure calcite are reported as a function of the pH in the absence and presence of dissolved ionic species and different surfactants. Three different ionic types of surfactants were used. Electrokinetic effects obtained for calcite at different pulp densities and in different ionic solutions are presented. Adsorption properties of ionic surfactants at different pulp densities are also discussed.