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›› 2007, Vol. 7 ›› Issue (2): 288-292.

• 反应与分离 • 上一篇    下一篇

微球状a-Fe2O3还原动力学

王建华,陶智超,杨勇,常杰,相宏伟,李永旺   

  1. 中国科学院山西煤炭化学研究所 煤转化国家重点实验室
  • 出版日期:2007-04-20 发布日期:2007-04-20

Reduction Kinetics of a-Fe2O3 Microspheres

WANG Jian-hua,SUI Zhi-chao,YANG Yong,CHANG Jie,XIANG Hong-wei,LI Yong-wang   

  1. State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences
  • Online:2007-04-20 Published:2007-04-20

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被引次数

1

摘要： 采用连续共沉淀和喷雾干燥相结合的方法制备出平均颗粒直径15.3 mm的微球状a-Fe2O3颗粒粉体，利用H2-TG还原实验手段结合Hancock-Sharp方法，研究了微球状a-Fe2O3在563~583 K温度范围内等温还原为Fe3O4的还原行为和还原动力学. 结果表明，随等温还原温度的升高，还原速率增大，在还原度a<0.8的还原阶段由a-Fe2O3转化为Fe3O4的还原反应是由相转变反应机理控制的，578 K以上恒温还原时，还原后期会发生部分Fe3O4的进一步还原. 在相转变机理控制的还原反应范围内，还原反应活化能为152.44 kJ/mol.

关键词: 微球状a-Fe2O3, Hancock-Sharp方法, 还原动力学

Abstract: The spherical a-Fe2O3 particles were prepared by the combination of continuous co-precipitation and spray-drying technology. The sample particles exhibited good spherical morphology with average diameter of 15.3 mm. The kinetic parameters of isothermal reduction of a-Fe2O3 to Fe3O4 in 563~583 K were obtained by H2-thermogravimetric analysis according to Hancock-Sharp method. The results show that the reduction rate increases with increasing reduction temperature, and the reduction reaction is predominantly controlled by phase change reaction mechanism when the reduction degree is lower than 0.8, partial Fe3O4 will be reduced to a-Fe2O3 in the terminal stage of the reduction process as the reduction temperature is higher than 578 K. Within the reduction range controlled by the phase change model, the activation energy is 152.44 kJ/mol.

Key words: a-Fe2O3 microsphere, Hancock-Sharp method, reduction kinetics