Investigation into the impact of High-Altitude conditions on the characteristics and flotation performance of pyrite grinding products

•The first systematic study of the effect of different altitudes on pyrite grinding.•Oxygenated flocculent (Fe-OOH) forms on the surface after pyrite grinding.•The area covered by oxygenated flocs decreases with altitude.•Grinding products have better flotation performance at high-altitude conditions. In high-altitude regions, the grinding process of pyrite is influenced by variations in dissolved oxygen (DO) levels at different altitudes, subsequently impacting the characteristics of the ground products and their flotation performance. In this study, a comprehensive investigation was conducted using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and single-mineral flotation analysis, to explore the effects of altitude-dependent DO environments on the characteristics of ground pyrite products and their flotation behavior. The results indicate that, in comparison to the N2 control group, as altitude decreases, the pH of the grinding slurry gradually decreases, while the dissolved oxygen content and redox potential of the slurry progressively increase. However, the ground products obtained under different altitude-dependent DO conditions exhibit smooth and even surfaces, with no apparent signs of corrosion; nevertheless, oxygen-containing flocculent structures (FeOOH) form on the surface of the pyrite. Furthermore, with decreasing altitude, the coverage area of these flocculent structures increases, leading to an unfavorable environment for the adsorption of sodium butyl xanthate on the pyrite surface. Consequently, pyrite samples ground in high-altitude DO conditions demonstrate enhanced flotation recovery performance, thus offering valuable insights for further theoretical investigations into the flotation behavior of high-altitude pyrite ores.