Enhancing the flotation performances of molybdenite fines relied on the synergistic interface regulation of faces and edges

The flotation of molybdenite particles smaller than 20 μm is inefficient primarily due to the reduction in overall hydrophobicity as particle size decreases. However, previous studies mainly focused on interfacial regulation of molybdenite faces or edges individually, resulting in unsatisfactory recovery and high collector consumption. In this work, an attempt was made to regulate the interfacial properties of both faces and edges synchronously to achieve highly efficient beneficiation of molybdenite fines utilizing a new compound collector consisting of emulsified kerosene and fatty alcohol polyoxyethylene ether phosphate (AEOP). The flotation results demonstrated that the compound collector was more superior than single collector in flotation, which promoted the flotation recovery greatly compared to emulsified kerosene or AEOP. In addition, the synergistic effect of kerosene and AEO-3P was much stronger than that of kerosene and AEO-9P. The results of zeta potential, electrochemical tests and scanning electron microscopy energy dispersive spectrometer (SEM-EDS) indicated that AEOP species preferentially adsorbed on edges, which enhanced the adsorption of emulsified kerosene droplets on edges via intermolecular interactions. Moreover, a portion of AEOP combined with kerosene droplets adsorbed on the molybdenite faces. X-ray photoelectron spectroscopy (XPS) results suggested that the phosphoric acid groups in AEOP bonded with Mo sites on edges. The contact angle results further confirmed that the compound collector synergistically acted on both faces and edges to improve its hydrophobicity. This work provides an innovative perspective to design effective compound collector for the flotation of molybdenite fines in future.