ABSTRACT

The kinetics of CO reduction of magnetite concentrate particles was investigated in drop-tube reactors (DTR) to obtain a rate equation for the design and analysis of a flash ironmaking reactor. The effect of CO partial pressure was determined and temperature was varied from 1473 K to 1873 K in few seconds of residence time similar to that in a typical flash reactor. The experimental data were divided into two temperature ranges, below 1623 K and above where the magnetite concentrate melts. The reduction degrees achieved at temperatures below 1623 K were under 50%, while significant reduction degrees (higher than 85%) were achieved at higher temperatures. Computational fluid dynamics (CFD) analysis was employed to improve the accuracy of the rate expressions. It was determined that the nucleation and growth kinetics best describes the investigated reaction. The activation energy was 451 and 88 kJ mol⁻¹, respectively, below and above 1623 K.

摘要

在落管式反应器（DTR）中研究了磁铁矿精矿颗粒的CO还原动力学，从而获得了设计和分析闪速炼铁反应器的速率方程。确定了CO分压的影响，并在几秒钟的停留时间内将温度从1473 K更改为1873 K，与典型的闪蒸反应器类似。实验数据分为两个温度范围，低于1623 K和高于磁铁矿精矿熔化的温度范围。在低于1623 K的温度下实现的还原度低于50％，而在更高的温度下实现了显着的还原度（高于85％）。计算流体动力学（CFD）分析用于提高速率表达的准确性。已确定成核和生长动力学最能描述所研究的反应。活化能为451和88 kJ mol^-1分别低于和高于1623K。