论文部分内容阅读
用热重法研究了铬铁矿含碳球团在氩气流中还原过程动力学,考察了还原温度、球团中配碳量和铬铁矿粉粒度等对还原过程的影响。应用颗粒模型对还原过程的实验数据进行了动力学解析,发现在本实验条件下,球团还原中对速度的限制步骤是铬铁矿颗粒还原产物层中的内扩散过程。进一步的分析步明,在 1 200℃ 以下和以上两个温度区间,该内扩散过程的活化能不同。分别求出了这两个区间的有效内扩散系数的阿仑尼乌斯表达式,得到了铬铁矿含碳球团还原过程的综合速度式。应用所获得的动力学方程对不同加热条件下的还原过程进行模拟计算,与实验结果相当符合。
The thermodynamics method was used to study the kinetics of the reduction process of chromitite-containing carbon pellets in an argon gas stream. The effects of reduction temperature, carbon content in the pellets and particle size of chromite on the reduction process were investigated. The kinetic analysis of the experimental data of the reduction process using the particle model shows that the limiting step in the reduction of the pellet under the experimental conditions is the internal diffusion process in the reduction layer of chromite particles. Further analysis shows that the activation energy of the diffusion process is different at below 1 200 ℃ and above two temperature ranges. The Arrhenius expression of the effective internal diffusion coefficient of these two intervals was obtained respectively, and the comprehensive velocity formula of the reduction process of chromitite-containing carbon pellets was obtained. The kinetic equation obtained was used to simulate the reduction process under different heating conditions, which was in good agreement with the experimental results.