微波促进MnO₂分解的动力学

来源期刊：中国有色金属学报1998年第3期

论文作者：华一新 刘纯鹏 乐莉

文章页码：497 - 501

关键词：微波； 分解动力学； MnO₂； Mn₃O₄

Key words：microwave； decomposition kinetics； MnO₂； Mn₃O₄

摘    要：将微波加热用于从MnO₂制备Mn₃O₄， 测定了MnO₂和Mn₃O₄的微波加热升温速率，并用差重法研究了在空气气氛中873～1 273 K之间MnO₂分解过程的动力学。结果表明， MnO₂ 很容易被微波加热， 而Mn₃O₄则几乎不吸收微波； MnO₂分步进行分解： MnO₂→Mn₂O₃→Mn₃O₄, 其中第一步的速率受通过产物层的传热控制，第二步受化学动力学控制。 用微波代替传统方式加热能显著地提高分解反应的速率，并能够降低过程的能耗。

Abstract: Microwave heating was used to prepare Mn₃O₄ from M nO₂. The microwave heating rate of MnO₂ and Mn₃O₄ was directly determined, and the kinetics of decomposition process of MnO₂ was investigated by gravimetric analysis under air atmosphere in the temperature range of 873~1273 K. It is demonstrated that MnO₂ can be heated well by microwaves, while Mn₃O₄ can not. The decomposition of MnO₂ is consisted of two steps: MnO₂→Mn₂O₃→Mn₃O₄, in which the first step is controlled by heat transfer through the product layer and the second by chemical kinetics. When using microwaves instead of conventional heating, the decomposition rate was significantly enhanced and the energy consumption for the process was reduced.