The present paper is concerned with the kinetics of thermal decomposition of manganese oxides and nonstoichiometric compounds formed in these reaction processes, studied by means of the thermal analyses (TG, DTA and DSC) and gas chromatography (GC).
The decomposition of MnO₂ to Mn₂O₃ proceeds at about 756 K, and the heat of reaction is 176±8 kJ/mol of O₂. For the decomposition of Mn₂O₃ to Mn₃O₄, the activation energy of about 163 kJ/mol of O₂ is obtained. The nonstoichiometric compounds, MnO_1.61 and MnO_1.42, seem to be formed in the thermal decomposition processes of MnO₂ and Mn₂O₃, respectively.