In the current study, a pseudo-2D XDEM packed bed reactor model is used to assess burden distribution effects in the firing of magnetite iron ore pellets. The model couples heat, mass, and momentum balances of the gas phase in each CFD cell to the relevant transport phenomena of each pellet. It was found that the model predictions in terms of temperature and final composition conform well with experimental measurements. Moreover, numerical results show that both of the tested methods, namely, physical (size-separated charge) and chemical (local addition of carbon) burden distributions can improve the thermal state of the firing bed. Furthermore, the results highlight that using size separated feed leads to homogeneity enhancement in final product quality; however, the local addition of carbon can severely deteriorate the quality.