Highly efficient flotation of ilmenite with a novel dithiocarbamate-hydroxamate collector.

The hydrophobization mechanism of N -[(3-hydroxyamino)-propoxy]- N -octyl dithiocarbamate (OAHD) towards ilmenite. [Display omitted] • N -[(3-hydroxyamino)-propoxy]- N -octyl dithiocarbamate (OAHD) was pioneeringly introduced into the direct flotation of ilmenite as an efficient collector. • In situ AFM observed the self-assembled adsorption of OAHD on ilmenite surface. • OAHD's dithiocarbamate (−C(=S)-S−) and hydroxamate (–NH(C=O)O−) groups both chelated with the surface Fe(II) species on ilmenite. • The "h" configuration of OAHD adsorption model intensified the hydrophobicity of ilmenite, which strengthened its flotation recovery. • A green and efficient flotation process of ilmenite was realized. The pre-activation of lead nitrate has been extensively proved to be an effective technique in ilmenite flotation, and sodium oleate is the preferred collector. Realization the clean flotation of ilmenite is an important aspect to respond the green and low-carbon policy. In this work, a dithiocarbamate-hydroxamate collector OAHD was pioneeringly added into the direct flotation of ilmenite as an efficient collector. The micro-flotation performance found that OAHD realized an efficient flotation of ilmenite under low concentration of 1.0 × 10−5 mol/L under around pH 8.0, and the flotation recovery rate of ilmenite reached about 94.2%, which was about 35.8% higher than that of NaOL. The morphology of ilmenite observed by AFM probed the self-assemble adsorption behavior of OAHD on ilmenite surface. DFT (density functional theory) calculations suggested that both dithiocarbamate and hydroxamate groups are the chemical active centers and have strong electron acceptability of d-orbital electrons of Fe atoms at/on the interface of ilmenite. UV–Vis spectra demonstrated that dithiocarbamte and hydroxamate groups simultaneously has strong chemical reaction with Fe2+ ions. XPS analysis recommended that OAHD chemisorbed on ilmenite surface to produce the surface Fe(II)-OAHD complexes where the O,O-five membered ring of Fe(II)-hydroxamate compounds were formed. [ABSTRACT FROM AUTHOR]