CFD modeling and analysis of particle size reduction and its effect on blast furnace ironmaking

Particle size reduction inevitably occurs inside ironmaking blast furnaces (BFs) but is not studied under BF conditions due to the lack of an effective tool. This paper simulates this phenomenon inside a 5000-m³ commercial BF using a recently developed three-dimensional computational fluid dynamics (CFD) process model. In particular, the sinter reduction degradation and coke gasification are modeled for considering the size reduction. By incorporating this information in the BF model, the in-furnace states and global performance are evaluated with respect to sinter reduction degradation index (RDI) under different conditions, e.g., keeping a constant blast rate or gas pressure drop. The results show that with increasing RDI, the bed permeability deteriorates, and there exists a critical value of RDI beyond which the decreased bed permeability leads to a significant drop in productivity for a given gas pressure drop. However, this problem can be mitigated substantially by charging more coke particles at the furnace periphery under the conditions considered. The proposed approach offers an extended capability to model and control BF operations.