Mechanism of polyaspartic acid as acid-base regulation depressant in reverse flotation separation of molybdenite and talc

The separation of talc and molybdenite through flotation has become a significant issue. The current inorganic and organic depressants demonstrate inadequate selectivity and limited efficacy in both positive flotation and reverse flotation of molybdenite. In this study, the utilization of the highly efficient green agent polyaspartic acid (PASP) as a molybdenite depressant was explored to investigate its pH-dependent acid-base depression mechanism. In the case of pH 4.0, molybdenite exhibited effective depression, talc was floated, PASP was desorbed at pH 10.0, and molybdenite was activated. In this study, the impact of electrostatic force on the adsorption process of PASP and examined the mechanism of PASP on molybdenite surface were studied by means of micro-flotation experiments, zeta potential measurements, analysis of solution chemistry, Fourier Transform Infrared Spectrometer (FT-IR) analysis, Ultraviolet-visible spectroscopy (UV-Vis) study, and X-ray photoelectron spectroscopy (XPS) detections. PASP produced chemisorption through the coordination of O or N atoms lone pair electrons with Mo2+ on the molybdenite surface. In this process, electrostatic repulsion determines whether the mineral can come into contact with PASP. (c) 2024 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights are reserved, including those for text and data mining, AI training, and similar technologies.