| 摘要 |
PURPOSE:To manufacture manganese dioxide having suitable quality for dry cell inexpensively by treating MnO2 with specified purity obtd. by oxidation of manganese carbonate in the soln. of H2SO4. CONSTITUTION:Manganese carbonate of high purity is obtd. by the reaction of aq. soln. of manganese sulphate with aq. soln. of alkali carbonate at 40-90 deg.C by admixing both solns. simultaneously with proportional quantities. Obtd. manganese carbonate is oxidized in a slightly pressurized humid atmosphere of O2 or air to produce MnO2 of >=70wt% MnO2 content. Then, the product is treated in H2SO4 soln. having 0.1-15mol/l concn. at 20-100 deg.C for 30min-1hr. Thus, MnO2 to be suitably used for dry cell having relatively high apparent density and superior discharge performance is obtd. |
