低品位软锰矿流态化还原焙烧

Fluidizing reduction roasting of low grade pyrolusite

  • 摘要: 采用流化床和马弗炉,进行了流态化还原焙烧与静态堆积焙烧对比实验,前者还原焙烧时间和还原效率明显优于后者.以CO和N2分别作为还原气体和流体介质进行了流态化还原焙烧实验,考察焙烧温度、焙烧时间和还原气氛等对还原效率的影响.在焙烧温度800℃、焙烧时间3 min以及CO体积分数10%时,软锰矿中二氧化锰的还原效率大于97%.在此基础上导出了还原动力学方程,并证实还原过程由界面化学反应控制,求得表观活化能为38.817 kJ·mol-1.

     

    Abstract: Contrast experiments between fluidizing reduction roasting and muffle furnace static roasting were performed with a fluidized bed and a muffle furnace. It is found that the former is obviously better in terms of roasting time and reduction efficiency. CO and N2 were used as reducing gas and fluid medium in fluidizing reduction roasting, respectively, and the effects of operation parameters such as roasting temperature, roasting time, and reducing atmosphere on the reduction efficiency were analyzed. When the roasting temperature is 800℃, the roasting time is 3 min, and the volume fraction of CO is 10%, a reduction efficiency of greater than 97% for MnO2 in pyrolusite can be achieved. The reduction kinetics was also investigated, and it is confirmed that the reduction process is controlled by interface chemical reaction. The apparent activation energy of the reduction is about 38.817 kJ·mol-1.

     

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