Abstract: In order to investigate the surface tension of sintered silico-ferrite calcium and aluminum（SFCA） and provide essential foundational data for exploring the bonding phase of calcium ferrite during sintering,the surface tension of complex calcium ferrite melts（including CaO-Fe₂O₃,CaO-Fe₂O₃-SiO₂,and CaO-Fe₂O₃-SiO₂-Al₂O₃system melts） in sinter was evaluated through model calculation.The results indicated that the model-derived results were in good agreement with the literature values of CaO-FeO-Fe₂O₃ system melt and the experimental measurements of CaO-Fe₂O₃-SiO₂ system melt,with average deviations of 3.57% and 4.53%,respectively.At 1 300 ℃,as the w（Fe₂O₃） in the CaO-Fe₂O₃ system melt increased from 72% to 84%,the surface tension decreased from468.0 mN/m to 433.9 mN/m.As the w（SiO₂） in the CaO-Fe₂O₃-SiO₂ system melt increased from 1.45% to8.39%,the surface tension decreased from 464.82 mN/m to 426.70 mN/m;As the w（C₄S₃） in the CaO-Fe₂O₃-SiO₂-Al₂O₃ system melt increased from 24% to 34%,the surface tension decreased from 405.54 mN/m to404.88 mN/m.This study provides a basis for the optimization of sintering process parameters,the effective control of particle bonding,and a deeper understanding of the reaction mechanisms of iron ore sintering.