流化床内生产碳化铁的动力学行为

Kinetics Behavior of Producing Iron Carbide in Fluidized Bed

在小型流化床内 ,利用CO CO2 H2 的混合气体还原铁矿粉 ,用气体分析仪对尾气成分进行检测 ,并与初始气氛相比较 ,得出还原速度和产品组成随时间的变化规律 ;应用缩核模型 ,对流化床内的铁矿石还原的动力学行为进行了描述 ,确定了反应的速度控制步骤·当初始气氛为6 0 %CO +2 0 %CO2 +2 0 %H2 时 ,在 5 5 0～ 70 0℃范围内表观活化能为 34.7kJ/mol;初始气氛为4 8%CO +32 %CO2 +2 0 %H2 时 ,在 5 5 0～ 6 5 0℃范围内表观活化能为 35 .

In mini fluidized bed, gas mixture (CO CO 2 H 2) was used to reduce iron ore. Based on the analysis of composition of exhausted gas, regularities for the changes of reduction rate and production components with respect to time were obtained. With the Shrinking core model applied, the kinetics behavior of this reduction in fluidized bed was described carefully, and the key step of the reduction was obtained. When the original composition of gas is 60%CO+20%CO 2+20%H 2, data of living energy is 34.7kJ/mol at 550～700?℃; When the original composition of gas is 48%CO+32%CO 2+20%H 2, data of living energy is 35.9kJ/mol at 550～650?℃. The dynamic factors that affect the reduction of iron ore can be obtained correspondingly based on these results.