INTERACTION OF SODIUM IONS WITH FELDSPAR SURFACES AND ITS EFFECT ON THE SELECTIVE SEPARATION OF Na- AND K-FELDSPARS

摘要

K-feldspar and Na-feldspar exhibit similar mineralogical, chemical and surface properties. Froth flotation is known to be the only technique to enable their separation. Our earlier studies revealed a good selectivity in the presence of K~+ and to a larger extent with Na~+ ions. In this context, in order to further identify the role of Na~+ ions in the selective separation of these minerals, ion selective electrodes were employed to determine the released Na and K ions released from albite and microcline into the solution and those adsorbed ions onto the mineral surfaces. Adsorption isotherms in feldsparslinorganic systems were constructed and the regions representing ion exchange and ion adsorption isotherms delineated. The mechanism of selective separation was elaborated on the basis of micro-flotation, solubility, adsorption and zeta potential measurements.