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真空碳热还原钛精矿中铁的等温动力学

Isothermal Kinetics of Iron in Vacuum Carbothermal Reduction of Ilmenite Concentrate

  • 摘要: 采用等温动力学研究的方法在1100~1300℃下对攀枝花钛精矿真空碳热还原中铁的动力学进行了研究。研究结果表明:还原温度的升高和保温时间的延长,能促进钛精矿中Fe3O4的还原以及铁的聚集长大;钛精矿中的铁在1100~1250℃保温的前期即0~30 min时,还原反应受界面化学反应控制,反应的表观活化能为207.92 kJ/mol;在1100~1200℃保温的后期即30~90min时,还原反应受内扩散控制,反应的表观活化能为521.47 kJ/mol。

     

    Abstract: The kinetics of Fe,in vacuum carbonthermal reduction of(Panzhihua) ilmenite concentrate,was studied.The influence of the reduction temperature/time on the extraction/growth of Fe-clusters via reduction of Fe3O4 was investigated with X-ray diffraction,scanning electron microcopy and energy dispersive spectroscopy.The results show that the reduction temperature and time had a major impact.For example,as the reduction temperature and time increased,the reduction rate of Fe3O4 increased,accompanied by increasing accumulation and growth of Fe-clusters.Initially reduced at 1100-1250℃ for 30 min,only surface/interfacial reduction happened,with apparent activation energy of 207.92 kJ/mol; but later reduced at 1100-1200℃ for 30 min~90 min,strong bulk reduction dominated,with apparent activation energy of 521.47 kJ/mol,because of thermal diffusion of the contents involved.We suggest that the reduction sequence be FeTiO3→Fe2TiO4→ FeTi2O5→Ti2O3.

     

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