MORPHOLOGICAL-CHANGES OF MANGANESE OXIDE PARTICLES BY THERMAL-TREATMENT

Morphological studies on the various manganese oxides obtained by ther mal decomposition of MnO2 (EMD I.C. No. 14) have been carried out base d on grain size analyses such as photo-transmission method, sedimentat ion gravimetry, and microscopy observation. It has been found that the grain size of the Mn2O3 and Mn3O4 particles evaluated by these method es fairly coincided with each other to give ca. 0.3 and 7.6 mu m, resp ectively. On the other hand the obtained grain size of the MnO2 starti ng material is strongly dependent on the pretreatment process before a nalysis, due to its fragile and porous structure. Based on the experim ental results, a morphology model has been proposed for manganese oxid e particles obtained by calcination of EMD.