An insight into fine cassiterite recovery: A novel surfactant-phenylpropylhydroxamic acid and its adsorption mechanism

The effective recovery of fine-grained cassiterite is a difficult problem in tin ore beneficiation. For enhancing the performance of the traditional collector for fine cassiterite flotation, a novel surfactant phenyl propyl hydroxamic acid (PHA) was designed by introducing one ethyl group (-CH2-CH2-) into benzohydroxamic acid (BHA).The study of flotation properties and the adsorption mechanism of PHA onto cassiterite surface were systematically investigated by scanning electron microscopy -energy dispersive X-ray spectroscopy testing (SEM -EDS), adsorption measurements, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Density functional theory (DFT). The results indicate that PHA has an excellent flotation performance for fine cassiterite compared with BHA and salicylhydroxamic acid (SHA), and the interaction between PHA and the surface of mineral mainly exhibited chemisorption attributed to new Sn-O chemical bonds. Meanwhile, DFT calculations showed that PHA adsorbed on the cassiterite surface via chelating interaction by the formation of a five -membered chelate ring.