Abstract: The influence of MgO on the reduction thermodynamics and kinetics of vanadium-bearing titanomagnetite carbon-containing pellet were studied and analyzed. The thermodynamic studies indicated that the MgO additive can promote the reduction reaction due to the replacement reaction between MgO and FeTiO₃, but the reduction reaction was restrained with the MgO-containing Fe-Ti-O compound production increased. The experimental results show that the reaction fraction of pellet is increased gradually by increasing the amount of MgO which the reduction temperature is lower than 1050℃;when the reduction temperature is more than 1050℃, there was a highest increase amplitude of the reaction fraction with the amount of MgO was 6%, the increase amplitude of the reaction fraction with the amount of MgO was 10% was the lowest, and the variety of the increase amplitude of the other samples was even. The kinetic study shows that the calculated value of three-dimensional diffusion model and interfacial reaction model fit well with the experimental values, it was concluded that the reduction process was controlled by diffusion and interface reaction. The reaction rate constant decrease gradually with increasing the amount of MgO.

Key words: magnesium oxide, vanadium-bearing titanomagnetite, thermodynamics, kinetics

摘要： 研究和分析了氧化镁对钒钛铁精矿含碳球团还原热力学和动力学影响。热力学研究表明：一方面在还原过程中添加氧化镁可以置换出钛铁矿中的氧化铁，促使还原反应进行；但另一方面，含氧化镁的铁钛化合物生成量增加，抑制了反应程度的进一步提高。实验结果表明：在还原温度低于1050℃时，随着氧化镁添加量的提高，球团的反应分数提高；在还原温度高于1050℃时，氧化镁添加量为6%时球团反应分数增加幅度最大，氧化镁添加量为10%时球团反应分数增幅最小，其余实验组的反应分数增幅变化较为一致。动力学研究表明：三维扩散模型和界面反应模型计算值更接近于实验值，说明添加氧化镁的钒钛铁精矿含碳球团的还原反应受扩散和界面反应混合控制；且随着氧化镁添加量的增加，反应的速率常数逐渐减小。

关键词: 氧化镁, 钒钛铁精矿, 热力学, 动力学