贫菱锰矿合成碱锰电池级化学二氧化锰研究

Research on Preparation of Chemical Manganese Dioxide for Alkaline Zn-Mn Battery from a Low-grade Manganese Carbonate Ore

以贫菱锰矿为原料合成碱锰电池用化学二氧化锰（CMD），系统研究了合成过程中各工艺因素对二氧化锰产品性能的影响。结果表明，CMD的视密度受中间产品MnCO3视密度影响较大，控制碳化结晶条件可以获得视密度达2．10g／cm^3的重质MnCO3；CMD的电活性主要与晶型有关，在350—400℃下热分解重质MnCO3所得γ型MnO2电活性最佳；通过热解产品精制可以提高CMD的MnO2含量，同时改善CMD颗粒形貌，获得了MnO2含量达91％，视密度为1．90g／cm^3，电容量为249．43 mAh的CMD最终产品。

Low-grade manganese carbonate ore was used as raw material to produce chemical manganese dioxide（CMD） for alkaline Zn-Mn battery. The effects of various factors in the process on CMD performance were investigated. The results show that CMD apparent density is significantly affected by that of the intermediate product MnCO3. Heavy MnCO3 with apparent density 2. 10 g/cm^3 can be obtained through controlling the carbonizing crystallization conditions. CMD electroactive is mainly related to its crystal phase. The electroactive of γ-phase MnO2 produced by pyrolysis of MnCO3 at 350 - 400℃ is the highest. Refining of the pyrolysis product can increase MnO2 amount and improve particle shape in CMD. Thus, a final CMD product containing 91% MnO2 with apparent density 1.90 g/cm^3 and discharge capacity 249.43 mAh can be obtained.