Improving the flotation of molybdenite fines based on the targeted regulation of edges using a novel chelating collector

Improving the flotation efficiency of molybdenite fines is a challenging job worldwide. In this work, sodium 2-Mercaptobenzothiazole (MBT) was explored as a potential collector to recover molybdenite fines efficiently. The flotation behaviors were estimated by micro-flotation tests. The interaction mechanism was probed by contact angle, Scanning Electron Microscope and Energy Dispersive Spectrometer (SEM-EDS), Zeta potential, X-ray Photoelectron Spectroscopy (XPS), adsorption capacity and density functional theory (DFT) calculation. The flotation tests revealed that MBT effectively improved the floatability of molybdenite fines at pH of 2 – 12, which exhibited stronger collecting ability than kerosene in the flotation of molybdenite fines. Contact angle, Zeta potential and adsorption capacity results revealed MBT enhanced the hydrophobicity of molybdenite surfaces, thus improving the flotation of molybdenite. SEM-EDS and adsorption energy results suggested MBT was more favorable to adsorb on edges (-268.87 kJ/mol) than that on faces (-40.09 kJ/mol). XPS and DFT calculation further demonstrated that N 2p and S 3p orbitals within MBT complexed with Mo 4d orbitals of two Mo atoms on edges to form a bidentate model. MBT had a good prospect of substituting kerosene in the flotation of molybdenite fines.