Recently, due to the explosive demand of secondary batteries and the depletion of the present amount of economically mined nickel sulfide mines, high-purity Ni smelting technology in nickel oxide mines is required. In this study, a study was conducted on the effect of the composition of slag on the distribution ratio of nickel in order to manufacture High-quality FeNi alloy from low-quality nickel oxide ore through MgO-SiO₂-FeO ternary slag. As a result, the appropriate equilibrium distribution time was derived to be 20 hours, and the distribution ratio of nickel increased linearly with the oxygen partial pressure. In addition, as the FeO content increases, the oxygen partial pressure increases, so the distribution ratio of nickel increases linearly. The dissolution behavior of nickel according to basicity (MgO/SiO₂) shows that when the basicity is 0.5~0.6 or lower, the nickel content in the slag decreases as the basicity increases, and when the basicity is 0.5~0.6 or higher, the nickel content in the slag increases as the basicity increases. Therefore, it was confirmed that the dissolution behavior of nickel during slag was amphoteric behavior.