<p>Carbon dioxide (CO₂) injection in basic oxygen furnace (BOF) steelmaking has emerged as a promising strategy to lower the overall carbon footprint of the process. In this study, a comprehensive kinetic model has been developed to simulate the interaction of CO₂ with molten Fe–x (<i>x</i>&#xa0;=&#xa0;C, Si, Mn, O) system under bottom-blown conditions. The model considers that gas phase and metal phase mass transfer resistances are of comparable magnitude and assumes equilibrium at the bubble–metal interface. This dynamic mixed controlled model also considers the effect of bubble size evolution during the travel inside the melt. Model predictions show good agreement with available experimental data with CO₂ bottom-blowing conditions. Various operating scenarios have been analyzed to evaluate CO₂ injection in both high-carbon and low-carbon melts showing decarburization and carbon pickup conditions, respectively. Furthermore, the interaction of CO₂ with different metalloids has been investigated to capture its behavior under typical BOF conditions. The influence of CO₂ injection on bath temperature and phosphorus content has also been examined. Overall, the study highlights the potential of CO₂ as a partial replacement for expensive inert gases such as argon, providing valuable insights for optimizing BOF operation toward reduced emissions and enhanced process efficiency.</p>