<p>Vanadium titanium magnetite (VTM) is a valuable resource, with blast furnace (BF) ironmaking being the primary process for its reduction to produce pig iron. However, during this process, an increased proportion of VTM leads to a surge in slag viscosity, which can severely disrupt stable BF operation. In this study, the modeling of the VTM reduction process is developed for the first time. This model is based on a recently developed BF process model. It incorporates a structure-based viscosity model to establish the relationship between liquid viscosity, temperature, and chemical composition. Additionally, the reduction of Ti and the effects of its reactant, Ti(C,N), on the viscosity are considered. The model is applied to simulate an industrial-scale BF, successfully capturing the significant increase in the liquid viscosity induced by the TiC and TiN precipitation. The study also investigates the effect of TiO₂ content in slag, a key parameter that is closely monitored in BF operations. The results, consistent with BF practice, reveal that an increase in TiO₂ content in slag negatively impacts BF operations, resulting in a higher gas pressure drop, a more severe potential flooding phenomenon, a reduced top gas utilization factor, and a lower liquid temperature. This work extends the capabilities of the CFD process model to simulate BF operations involving VTM, facilitating control and optimization for better efficiency and reliability.</p>