Synthesis of sodium oleate hydroxamate and its application as a novel flotation collector on the ilmenite-forsterite separation

Collectors are important for mineral flotation. In this work, a novel hydroxamic acid collector, i.e. sodium oleate hydroxamate (NaOLH), was synthesised and applied for ilmenite flotation. The collector was designed by constructing an oleic acid chain and hydroxamic acid group into the collector's molecular structure, based on the flotation mechanism of ilmenite. Liquid chromatography/mass spectrometry and nuclear magnetic resonance spectroscopy were employed to identify the component and structure of NaOLH. Micro-flotation was performed to explore the flotation performance of NaOLH. The absorption mechanism was investigated by zeta potential, Fourier transforms infrared spectroscopy, and X-ray photoelectron spectroscopy. Results demonstrated that NaOLH had a stronger flotation performance than the conventional collector sodium oleate (NaOL). The NaOLH was adsorbed onto the surface of the ilmenite and forsterite, and the O and N atoms of NaOLH were mainly chemisorbed on ilmenite via Fe and Ti sites on the surface, whereas mainly reacted with Mg sites on the forsterite surface. The distribution of NaOLH and NaOL at the solid-liquid interface was studied by molecular dynamics simulation. Results showed that the adsorption capacity between NaOLH and ilmenite was stronger than that of NaOL. Taken together, results suggest that the NaOLH is a potentially novel and a promising collector for ilmenite flotation.