| 摘要 |
PURPOSE:To obtain a manganese oxide for dry cells having an extremely low rise in internal resistance, especially in low-rate discharge with a remarkably higher activity at a markedly lower cost than those of electrolytic manganese dioxide by subjecting manganese oxide to aluminum treatment under specific pH conditions in the course of a production process for chemical converted manganese dioxide. CONSTITUTION:The above-mentioned manganese oxide for dry cells is produced by chemical treatment, contains >=88wt.% MnO2 and 0.03-6wt.% Al and has 1.6-2.5g/cm<3> tap density and the main crystal structure formed from gamma-MnO2. The afore-mentioned manganese oxide is obtained by the following method. That is fine powder of a manganese compound is roasted to form manganese oxide consisting essentially of Mn2O2 and/or Mn3O4, which is subsequently treated with a mineral acid to afford manganese oxide consisting essentially of the gamma-MnO2. The resultant manganese oxide is then treated in an aqueous medium at pH2.0-4.0 or >=10 containing an aluminum compound. |
