Abstract：Manganese trioxide powder, an important raw material for the production of soft ferrite, was prepared
by vacuum pyrolysis with manganese sulfate as raw material. The sample Mn3O4 was characterized by XRD and
SEM. The thermal decomposition behavior of MnSO4 ·H2O was analyzed. The effects of vacuum pyrolysis temperature,
time and vacuum on the quality of Mn3O4 were studied. The results show that with the increase of pyrolysis
temperature, the content of Mn2O3 in the thermal decomposition products of MnSO4 ·H2O decreases and the content
of Mn3O4 increases; When the pyrolysis temperature is 900 ℃, the sample MnSO4 ·H2O is completely decomposed
and the product is pure Mn3O4. With the extension of pyrolysis time, the purity of Mn3O4 in the obtained product is
higher and higher. When the pyrolysis time is 1.5 h, the product obtained by thermal decomposition is complete
Mn3O4. The higher the vacuum degree (the lower the system pressure) is, the higher the purity of Mn3O4 in the product
is. When the degree of vacuum is 18 kPa, the product obtained by thermal decomposition is almost Mn3O4.
2021, Vol. 31 
