Surface-Properties of Magnesite and Surfactant Adsorption Mechanism

Abstract

In this study, effects of various ions and flotation reagents in magnesite-serpentine flotation were investigated with the aim of overcoming the problems encountered in selective flotation of magnesite and serpentine. In order to examine the adsorption mechanism of reagents in magnesite-serpentine flotation, electrokinetic potential and zero point of charge of pure magnesite and serpentine were determined,the effect of various ions such as, Mg2+, Ca2+, Na+, CO32-, SiO32-, and flotation reagents such as, oleic acid, sodium oleate and amine on surface properties of magnesite and serpentine were examined. Infrared spectra studies were carried out in order to interpret and elucidate the adsorption mechanism of reagents of magnesite-serpentine having z.p.c. (zero point of charge) at pH 5.8. Infrared spectrophotometry studies indicated that RCOO(-) ion was chemically adsorbed on the surface of magnesite, and it was physically adsorbed on the surface of serpentine while NH3+ ion was physically adsorbed on the surfaces of both minerals. Magnesite-serpentine separation was performed in two ways applying froth flotation method. In the direct flotation magnesite was concentrated in the float fraction and in the reverse flotation magnesite was enriched in the sink fraction.