International Journal of Mineral Processing, Vol.133, 29-38, 2014
Surface chemistry aspects of bastnaesite flotation with octyl hydroxamate
Surface chemistry features of bastnaesite were investigated with respect to octyl hydroxamate adsorption and the wetting characteristics at different levels of hydroxamate adsorption. The wetting characteristics of bastnaesite in the absence of collector adsorption were examined using both contact angle measurements and MD simulations. As expected, it was found that bastnaesite is naturally hydrophilic. Surface chemistry studies included octyl hydroxamate adsorption by the solution depletion method. The surface state was described by sum-frequency vibrational spectroscopy (SFVS) and molecular dynamic simulations (MDS). The adsorption isotherm at low levels of hydroxamate adsorption was established and the hydrophobic surface state was described from contact angle measurements. The relationship between hydrophobicity and adsorption density was examined for the first time by MD simulations. The SFVS spectra indicate that a well-ordered monolayer was formed at a hydroxamate concentration of about 1 x 10(-4) M. (C) 2014 Elsevier B.V. All rights reserved.