| 摘要 |
PURPOSE:To prepare manganese dioxide having high bulk density and excellent discharge characteristics, and suitable for an electric cell, by calcining manganese carbonate under oxidizing condition, and reacting the oxidized product with an alkali metal chlorate in a solution acidified with nitric acid. CONSTITUTION:Manganese carbonate having a bulk density of about >=1.9 is prepared e.g. by reacting manganese sulfate solution with ammonium carbonate. The manganese carbonate is subjected to oxidative calcination in humid air or humid oxygen atmosphere at 250-400 deg.C under normal pressure -5kg/cm<2>G. The resultant oxidation product composed mainly of manganese dioxide is made to react with alkali metal chlorate in a solution containing manganese nitrate and nitric acid and acidified with nitric acid. Manganese ion is oxidized to manganese dioxide by this process, and at the same time, the manganese dioxide is precipitated on the oxidation treatment product to give manganese dioxide having high bulk density and improved discharging characteristics. |
