<p>To optimize the use of high-SiO₂ magnetite concentrate and foster the development of magnesium acid pellets, a series of thermogravimetry experiments were conducted to investigate the oxidation behavior of pellets with varying MgO content, all maintaining 5% SiO₂ content. This study monitored the weight gain throughout the pellet oxidation process using an electronic balance and employing the unreacted core model (UCM) to dissect the kinetics of the oxidation mechanism. Phase transitions and microscopic structures of the pellets were further analyzed through XRD and SEM, and the results revealed that an increment in MgO content reduced the oxidation ratio of the pellets from 40.96% to 21.82% over 30&#xa0;min, demonstrating that the effect of MgO serves to inhibit the oxidation of high-silicon magnetite concentrate. Owing to the reaction of MgO and SiO₂ in the gangue phase with FeO in magnetite to form an MF-phase [(Fe_x·Mg_1−x) O·Fe₂O₃] and fayalite, thereby restraining the oxidation of magnetite, the content of hematite and gangue phases decreases from 32.96% and 15.07% to 20.63% and 11.70%, respectively. This is consistent with the results of thermodynamic calculations. Meanwhile, the theoretically derived oxidation time from UCM exhibited consistency with the experimentally obtained results, confirming the applicability of UCM in delineating the oxidation dynamics of high-silicon magnesium pellets.</p>