球团矿还原的动力学模型分析

基于还原炉控温还原实验,通过分析CO和H2还原球团矿过程中的反应速率模型,提出两种气体混合后还原球团矿的反应动力学模型,得到还原过程中阻力和反应速率随温度及还原度的变化规律,得出结论:CO还原球团矿时,内扩散阻力所占比例随着温度及还原度增加而变大;H2还原球团矿时,内扩散属于速率控制环节;混合气还原球团矿时,反应速率随温度升高而增大,温度低于500℃时,CO浓度增加,反应速率降低,而温度超过500℃后,反应速率则随着CO浓度的增加而增大;混合气反应速率模型的计算值与实验结果一致。

Analysis on reaction dynamics model of pellets

Through analyzing the reaction rate model of CO and H2 in the process of reducing pellets and based on experiments,the changes of resistance and reaction rate with the increase of temperature and reducibility is concluded respectively.Reaction rate model of gas mixture is concluded based on the two kinds of model.The proportion of internal diffusion resistance increases with the increase of temperature and reduction degree when pellets are reduced by carbon monoxide.Internal diffusion belongs to the rate control link when pellets are reduced by hydrogen.The reaction rate increases with temperature increasing while it decreases with carbon monoxide content increasing in the process of gas mixture reducing pellets when temperature is below 500 ℃.It will increase with the increase of the carbon monoxide concentration while temperature is over 500 ℃.Theoretical calculation value of gas mixture is consistent with the experimental results.