Effects of monohydric alcohols on the flotation of magnesite and dolomite by sodium oleate

Part of NaOL (sodium oleate) was replaced with different monohydric alcohols (butanol, hexanol, and octanol) in the flotation of magnesite and dolomite for lower flotation costs and higher flotation efficiency. Zeta potential analyses, contact angle measurements and molecular simulations were used to investigate mechanisms of the adsorption of alcohols. Single mineral flotation tests showed that combined reagents could produce better flotation results than single NaOL. Contact angles and zeta potentials of the two minerals indicated that alcohols were adsorbed on mineral surfaces physically and improved the hydrophobicity when combined with NaOL. Molecular dynamics simulation was used to explore mechanisms of alcohols at the molecular level. Different adsorption models indicated that alcohols could increase NaOL density and the thickness of the hydrophobic layer on both mineral surfaces. As a result, the flotation of magnesite and dolomite was enhanced. Based on molecular dynamics calculation, the adsorption mode of octanol on mineral surfaces, when combined with NaOL for flotation, was shown to be adsorbed through hydrogen bonds. (C) 2017 Elsevier B.V. All rights reserved.