Experiments were performed using Sokolov-Sarbaisk and Kachkanar pellets to study the effect of the composition of the gas phase with different oxygen contents on the degree of completion of oxidation processes that affect the properties of the obtained pellets. As a result of processing the obtained experimental data and using the law of acting masses, equations have been compiled that relate the dependence of the oxidation degree of fluxed pellets on the oxygen content in the gas phase, the roasting temperature, and the heating rate of the pellets. The results of this work are of certain interest and can be used to determine the necessary duration of heat treatment of pellets in the heating and roasting zones of conveyor machines, which provides pellets with the required metallurgical properties, as well as to justify optimal fuel consumption.