Industrial-scale DEM modelling of segregation in the blast furnace charging system

Segregation of the ferrous burden during blast furnace (BF) charging can cause uneven layer formation at the furnace throat, reducing bed permeability and disrupting gas–solid interaction. This study applies a discrete element method (DEM) model to the industrial-scale BF charging system (from the skip car to top hopper discharge) to examine segregation under real operating conditions. The model includes the full ferrous mixture (pellets, sinter, lump ore, and nut coke) and the real-scale geometries. A reference case representing current practice is analysed in detail and compared with systematically varied case studies. The results show that segregation generally decreases from the skip car to the top hopper due to partial remixing, but strong segregation is still observed. Lump ore and nut coke exhibit the strongest segregation, while pellets remain the least segregated. The order of pellets and sinter in the weighing bunkers strongly influences their segregation patterns, whereas variations in the sinter particle size distribution (PSD) and particle shape have only limited effects. The insights from this study provide a basis for developing practical strategies to mitigate segregation in industrial BF charging. • Industrial-scale DEM applied to blast furnace charging system. • Segregation of the ferrous mixture analysed under real conditions. • Segregation generally decreases from skip car to top hopper. • Lump ore and nut coke segregate strongly; pellets segregate least. • Bunker order strongly affects segregation; PSD and shape effects are relatively minor.