<p>In nickel flash smelting, the adhesion of Fe₃O₄ to low-nickel matte results in the physical entrapment loss of valuable metals in slag, posing a critical barrier to improving copper and nickel recovery rates. In this study, the interfacial adhesion behaviors between Fe₃O₄ and representative sulfides in low-nickel matte, including FeS, Ni₃S₂, and Cu₂S, were systematically investigated using first-principles density functional theory (DFT) calculations to elucidate the underlying adhesion mechanisms. The calculated adsorption energies of the (111) crystal plane of Fe₃O₄ with FeS, Ni₃S₂, and Cu₂S are −13.74, −5.91, and −13.19 eV, respectively, substantially higher than those associated with SO₂ and other matte constituents. This indicates that interfacial adhesion dominates the separation process between slag and matte at the interface. Electronic structure analysis reveals there exists significant charge transfer and covalent bonding between FeS, Cu₂S with Fe₃O₄, as evidenced by distinct hybridization peaks in the density of states (DOS) near −4.23 and −4.60 eV. In contrast, Ni₃S₂ exhibits weaker interfacial polarization and lower binding strength. Based on these findings, strategies such as reducing the Fe/SiO₂ ratio, raising the smelting temperature, and minimizing oxygen partial pressure and Fe₃O₄ content are proposed to enhance fluidity and interfacial tension between low-nickel matte and slag, which accordingly mitigate the adhesion effect between the Fe₃O₄ and low nickel matte, thereby offering theoretical guidance for improving the recovery efficiency of valuable metals during matte smelting.</p>