The role of a fatty alcohol in improving calcium minerals flotation with oleate

Abstract

The adsorption mechanism of collector mixtures and the implication for mineral flotation are discussed in light of the results of a quantitative study of the flotation of fluorapatite and calcite with mixtures of fatty alcohol and oleate collectors. It was found that the recovery of fluorapatite and calcite floated with oleate improved considerably after addition of the fatty alcohol. With oleate alone, the low mineral flotation was attributed to a patchy oleate surface coverage and oleate dimers but with the collector mixture it was shown that the fatty alcohol co-adsorbs with oleate on the mineral surface and in a much larger quantity than when it was used alone. Spectroscopic analyses reveal that the amount of oleate adsorbed remains similar when added alone or in mixtures, which implies that the co-adsorption of the fatty alcohol is responsible for the improved mineral flotation. Replacement of oleate dimers with fatty alcohol-oleate complexes at the mineral surface may also explain the increase mineral hydrophobicity and flotation.