摘要
采用热重分析实验技术,在O_2—N_2混合气流中,700～1200℃范围内研究了磁铁矿球团氧化过程动力学。实验发现在1100℃以下各温度反应时,氧化度X在较短时间内达到各自的某一临界值X_C后,氧化速度大为降低,X(t)趋近于饱和值。X_C值随温度的升高而增大,在1100℃以上,X_C趋近于1,于是提出了两段扩散控制的氧化过程动力学模型,得到了两段中的动力学参数的阿仑尼乌斯表达式及X_C温度间的经验关系式。应用本动力学模型模拟计算的结果与实测值取得了相当好的一致性。
The oxidation kinetics of magnetite pellets has been investigated in mixing gas flow of O_2-N_2 and within the temperature range of 700-1200℃ using thermogravimetric analyses. The experimental data show that at reaction tem peratures below 1100℃ after each oxidation rates reached cristical value x_c respectively, the oxidation velocities are falling intensely and x(t) close to saturated values respectively. Along with the rise of reaction temperature, the x_c becomes larger. At temperatures above 1100℃, the x_c closes to unit. An oxidation kinetics model of two periods diffusions control has been developed. The Arrhenius equations of the kinetics parameters and a empirical relationship between x_c and temperatures were obtained. The calculated results from the model are fit closely with observed data.
出处
《烧结球团》
北大核心
1990年第4期1-5,共5页
Sintering and Pelletizing
