Chalcopyrite and bornite are typical copper sulfide minerals; however, the interaction mechanisms between these minerals and conventional collectors—sodium butyl xanthate (BX) and ammonium dibutyl dithiophosphate (ADD)—when used in combination remain unclear. To address this issue, this study integrated flotation tests, FTIR spectroscopy, adsorption measurements, and AFM to investigate the effects of BX, ADD, and their mixture on the floatability of the two minerals. Flotation results showed that chalcopyrite exhibited excellent floatability in all collector systems, with above 90% recovery. Within the pH range of 3 to 11, BX outperformed ADD in enhancing bornite flotation. The BX/ADD mixture at a mass ratio of 3:1 had no significant effect on chalcopyrite recovery but significantly improved bornite recovery to 84.20% at pH 9. FTIR confirmed chemical adsorption of both collectors on the mineral surfaces. AFM further visualized stronger adsorption of BX on both chalcopyrite and bornite. Compared with single BX or ADD alone, the BX/ADD mixed collector exhibited more effective adsorption on chalcopyrite and bornite. The study provides guidance for reagent selection in the industrial flotation of chalcopyrite and bornite.

The Emeishan Large Igneous Province (ELIP) contains high-Mg volcanic rocks, evolved basalts, and Fe-Ti-V-oxide-bearing layered intrusions, providing a natural system for investigating the coupled effects of H₂O and the redox state on silicate crystallization. We modeled three representative starting melts, namely Melt-6 (basaltic), Melt-8 (meimechitic), and Melt-10 (komatiitic), at 5 kbar under prescribed fO₂ conditions spanning ΔFMQ = −3 to +3 using rhyolite-MELTS. The simulations show that the starting melt composition sets the liquidus temperature and controls whether olivine saturates first. H₂O depresses silicate saturation temperatures, with the strongest effect on plagioclase, whereas fO₂ modifies phase relations mainly through Fe²⁺/Fe³⁺, effective FeO activity, and competition with Fe-Ti oxide saturation. The orthopyroxene saturation temperature and enstatite-ferrosilite (En-Fs) composition show the strongest redox response, whereas clinopyroxene is buffered by Ca occupancy in the M2 site and plagioclase records mainly the H₂O content and residual melt evolution. These results support a coupled model in which the starting melt, H₂O, and fO₂ jointly control crystallization paths and Fe-Ti-V oxide enrichment in ELIP layered intrusions.