Kinetics of hausmannite preparation by thermal decomposition of manganese sulfate
In order to get the mechanism of hausmannite prepared by the decomposition of manganese sulfate in air,the thermal decomposition behavior of manganese sulfate was studied with TG-DSC and XRD,and the kinetics of dehydration and decomposition was studied with non-linear iso-conversional method and the universal integral method.Mampel Power principle G(α)=α3/2 was used to describe the dehydration kinetics of manganese sulfate between 200℃ and 400℃.The average activation energy of the dehydration was calculated to be 117.11 kJ·mol-1.MnSO4 was decomposed to form Mn3O4 while the temperature was between 750℃and 1050℃.The decomposition kinetics could be described as G(α)=1-(1-α)1/2,and its average activation energy was 226.44 kJ·mol-1.The result of isothermal decomposition kinetics of manganese sulfate agreed with its non-isothermal kinetics by TG-DSC analysis.