Abstract: The efficient recovery of valuable metal resources, such as iron, nickel, cobalt and copper, from iron-rich nickel slag represents a key technical bottleneck in the comprehensive utilization of nickel slag resources. This study focused on metallized pellets produced by the reduction of modified nickel slag. Firstly, the thermodynamic analysis of the CaO-MgO-SiO₂ slag system for these pellets was carried out using FactSage software, and the composition of secondary slags and melt characteristics were determined through phase diagrams and equilibrium calculations. Then, the effects of melting temperature, alkalinity and other factors on the recovery rates of valuable metals, such as iron, nickel, cobalt and copper in metallized pellets were investigated through experiments. The migration and enrichment characteristics of the target metals were also explored during the melting separation process, the optimal processing parameters were identified, and the underlying mechanism was analyzed. Thermodynamic calculations showed that when the slag system alkalinity of modified nickel slag metallized pellets was within the range of 0.7~0.9, the melting temperature was lower than 1 400 ℃, the viscosity was 0.2~0.4 Pa·s, and the secondary slag phase was the pyroxene phase. Experimental results showed that when the melting temperature was 1 600 ℃, and the alkalinity was 0.9, the recovery ratio of melted iron reached 95.31%. The enrichment and recovery ratios of nickel, cobalt and copper were all satisfactory.