不同形态Fe对Cr2O3还原的影响

Effect of various states of Fe on the reduction of Cr2O3

  • 摘要: 通过1350-1550℃下Fe-Cr2O3、Fe2O3-Cr2O3和FeCr2O4的碳还原实验,结合X射线衍射和扫描电子显微镜考察不同形态铁(Fe、Fe2O3和FeO)对Cr2O3还原的影响.同一温度下最终还原度及还原速率均呈现Fe2O3-Cr2O3-C〉FeCr2O4-C〉Fe-Cr2O3-C的趋势,三种样品的还原都经历了氧化物→碳化物→Fe-Cr-C合金的过程;低碳碳化物的产生以及较早形成金属液相使Fe2O3-Cr2O3还原更充分,合金液相中碳溶解量低导致FeCr2O4的还原率偏低,而碳化物偏多、合金液相偏少阻滞了Fe-Cr2O3还原率的提高.实验得到Fe-Cr2O3-C、FeCr2O4-C和Fe2O3-Cr2O3-C体系的表观活化能分别为142.90、111.84和128.9 kJ·mol-1.

     

    Abstract: The effect of various states of Fe(Fe,FeO,and Fe2O3) on the reduction of Cr2O3 was investigated by conducting isothermal experiments on the reduction of Fe-Cr2O3,Fe2O3-Cr2O3 and FeCr2O4 by graphite at 1350-1550℃ combined with X-ray diffraction and scanning electron microscopy with energy-dispersive spectrometry. It is shown that the tendency of final reduction degree is Fe2O3-Cr2O3-C 〉 FeCr2O4-C 〉 Fe-Cr2O3-C at each temperature,and the transformation path of the three samples is oxides → carbides → Fe-Cr-C alloy. Liquid alloy which earlier emerges and low carbon-content carbides promote the reduction of Fe2O3-Cr2O3. Low carbon dissolution in liquid alloy limits the reduction degree of FeCr2O4. The large amount of carbides and little liquid alloy retard the reduction of Fe-Cr2O3. The apparent activation energies of Fe-Cr2O3-C,FeCr2O4-C and Fe2O3-Cr2O3-C are 142.90,111.84 and 128.9 kJ·mol-1,respectively.

     

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