Oxidation kinetics of iron sulfide in the form of dense plate,pellet and single particle

The oxidation behaviours of pyrrhotite in the form of dense plate, pellet and single particle were compared. In the oxidation of dense plate of FeS, preferential oxidation of iron took place to form a dense oxide layer in the earlier stage of oxidation, and the subsequent oxidation accompanying the evolution of SO₂ gas proceeded after the composition of pyrrhotite attained Fe_0.9S. In the oxidation of FeS pellet, both the above reactions take place simultaneously because the pellet consists of fine particles. In the oxidation of single particle of small size, ignition of the particle occurred due to the heat of oxidation, and the particle melted in a very short time less than 1 second.