A novel method of accounting for the oxidation of magnetite during iron ore pellet induration in a rotary kiln is presented. The technique is based on the mathematical description of a cascading bed of pellets in a rotary kiln by Saeman (1951). For the purpose of illustration, this method was incorporated into a simple one-dimensional model of heat and mass transfer in a natural gas fired rotary kiln furnace. The model predicts a fraction of magnetite oxidation less than 5%, which is in agreement with plant observations.