A mathematical model based on the computational fluid dynamics method, heat and mass transfer in porous media and the unreacted shrinking core model for the oxidation reaction of an individual magnetite pellet during preheating was established. The commercial software COMSOL Multiphysics was used to simulate the change in the oxidation degree of the pellet at different temperatures and oxygen concentrations, and the simulated results were compared with the experimental results. The model considered the influence of the exothermic heat of the reaction, and the enthalpy change was added to calculate the heat released by the oxidation. The results show that the oxidation rate on the surface of the pellet is much faster than that of the inside of the pellet. Temperature and oxygen concentration have great influence on the pellet oxidation model. Meanwhile, the exothermic calculation results show that there is a non-isothermal phenomenon inside the pellet, which leads to an increase in temperature inside the single pellet. Under the preheating condition of 873–1273 K (20% oxygen content), the heat released by the pellet oxidation reaction in a chain grate is 7.8 × 10⁶–10.8 × 10⁶ kJ/h, which is very large and needs to be considered in the magnetite pellet oxidation modelling.

基于计算流体动力学方法，多孔介质中的传热和传质以及预反应过程中单个磁铁矿颗粒氧化反应的未反应收缩核模型，建立了数学模型。使用商业软件COMSOL Multiphysics模拟了不同温度和氧气浓度下颗粒氧化程度的变化，并将模拟结果与实验结果进行了比较。该模型考虑了反应放热的影响，并添加了焓变以计算氧化释放的热量。结果表明，丸粒表面的氧化速率比丸粒内部的氧化速率快得多。温度和氧气浓度对颗粒氧化模型有很大影响。同时，放热计算结果表明，颗粒内部存在非等温现象，导致单个颗粒内部温度升高。在873–1273 K（氧气含量为20％）的预热条件下，链条炉排中颗粒氧化反应释放的热量为7.8×10⁶ –10.8×10 ⁶  kJ / h，这非常大，在磁铁矿颗粒氧化建模中需要考虑。