<p>Magnesia fluxed pellets were prepared via oxidation roasting using ludwigite (a boron-bearing iron ore) as the magnesium source, with quicklime added to adjust the binary basicity (CaO/SiO₂). The effects of binary basicity, roasting temperature, and roasting time on the cold compressive strength (CCS) and mineral phase evolution of the roasted pellets were systematically investigated, and the results demonstrated that rational parameter regulation promoted the formation of moderate calcium-containing silicate liquid phase, facilitated hematite recrystallization, and strengthened inter-mineral bonding, while excessive liquid phase induced by over-high temperature or basicity disrupted particle consolidation and deteriorated bed permeability in industrial roasting and smelting. The optimized pellets exhibited a dense microstructure with recrystallized hematite as the core skeleton, and magnesium ferrite, calcium silicate, and calcium iron pyroxene as the intergranular binding phases. The CCS of the pellets first increased then decreased with rising roasting temperature (1175–1275°C) and extended holding time, and showed an overall upward trend with binary basicity from 0.4 to 1.0, with an abnormal drop at 0.8 caused by penetrating cracks and the porous structure. The optimal process parameters were determined as binary basicity of 1.0, roasting temperature of 1250°C, and holding time of 10&#xa0;min, under which the pellets achieved an average CCS of 3056 N per pellet, effectively mitigating the strength degradation induced by MgO addition.</p>