The current study revisits the particle combustion modeling in the simulation of iron ore pellet indurator, which is the process to dry and fire the pellets as a pretreatment for blast furnace. Although the shrinking core model has been frequently used in the previous studies due to its simplicity, its limitation for the porous pellet should have been evaluated. Instead, the grain model could have been used as it conceptually gives the better description. In that context, the shrinking core model is compared against the grain model in the simplified isothermal condition and the complete indurator simulation to demonstrate the applicability. Despite the possible differences in the conversion profiles along the reaction regimes, the models provide apparently reasonable bed temperature results for the normal indurating conditions. However, the shrinking core model needs to be applied with caution and its validity should be questioned when the operating conditions change. (C) 2016 Elsevier Ltd. All rights reserved.