Chlorination of manganese oxides

In this work the reaction between several manganese oxides and chlorine is investigated. The reaction path for the chlorination of the oxides is established, which involves recrystallization of high valence manganese oxides: Mn3O4 and Mn2O3 during the chlorination of MnO, and Mn2O3 during the chlorination of Mn3O4 and Mn2O3. The starting temperature for the reaction of the oxides is determined by non-isothermal thermogravimetric measurements. Analysis of the samples at different reaction degrees reveals that three simultaneous processes are taking place during the whole reaction: chlorination, volatilization of manganese chloride and recrystallization of manganese oxides. The effect of temperature in the reaction rate is analyzed. The activation energies obtained for the reaction of the three oxides with chlorine, which are in accordance with the vaporization enthalpy of MnCl2, suggest that although during the mass loss three processes occur (chlorination, recrystallization and volatilization), volatilization of manganese chloride has a strong influence in the rate observed.