Novel insights into the role of colloidal calcium dioleate in the flotation of calcium minerals

Abstract Previous studies on oleic acid systems have shown that calcium dioleate formed during the flotation process plays an important role. Calcium dioleate has been extensively studied as an important intermediate product in sodium oleate flotation of calcium-containing minerals sodium oleate, but its use as a collector to separate calcium-containing minerals remains unverified. The effect of calcium dioleate on fluorite, calcite and scheelite flotation and the adsorption mechanism on the mineral surface were examined using solution chemical analysis, flotation test, adsorption measurement, atomic force microscopy (AFM) and transmission electron microscopy (TEM) in this study. Solution chemical calculations prove that stable calcium dioleate colloid will be the dominant species at certain pH, calcium ion and oleate concentrations. Flotation experiments showed that the calcium dioleate plays an important role in the flotation process using sodium oleate. Calcium dioleate has better flotation effect for fluorite and scheelite but weaker effect for calcite than sodium oleate. Adsorption measurement showed that calcium dioleate is more easily adsorbed on the surface of scheelite and fluorite. AFM and TEM measurements exhibited that the formation of micelle adsorption on the surface of scheelite and fluorite caused by calcium dioleate clearly affects the surface roughness. Calcium dioleate colloids can likely enhance the surface roughness of scheelite and fluorite via selectively adsorption to improve the flotation of scheelite and fluorite.