Numerical simulation of solid flow and segregation in a blast furnace by coupling granular rheology and transport equation

•A mathematical model is proposed for solid flow in the blast furnace.•The model captures the deadman, plugging and converging zones.•It calculates the burden stress based on elastoplasticity.•The particle diffusion and segregation are included in the model.•The model is continuum-based and computationally efficient. Mathematical modelling is very useful for realizing a full-scale simulation of the ironmaking process in a blast furnace (BF). A continuum model is proposed for this purpose here, which couples the elasticity, flow rheology, diffusion and segregation of binary granular materials. This model is shown to reproduce the flow patterns of BF like the deadman, converging zone and plugging zone, in both concentric and eccentric discharging BF, given careful consideration of the boundary conditions. Good agreement with the burden stresses up-scaled from a discrete particle simulation is also achieved. Its validity to model the particle percolation is testified using two representative cases - the charging and the descending processes of BF, respectively. The yielded local particle concentration is shown to be comparable with those of DEM and experiment. The proposed model and method are promising in addressing the complicated solid flow, mixing and segregating problems of binary particles in a BF.