竖炉生产直接还原铁过程的数值模拟

采用基于气相和固相的质量和能量的竖炉一球团（块矿）法直接还原炼铁的一维数学模型．含铁原料的还原采用三界面未反应核模型，并考虑了热量损失，得到了各物质的组成和温度在炉内的分布．以Gilmore厂Midrex作为对象进行模拟，模型结果与生产数据相符，验证了模型的准确性．模拟结果表明：Midrex竖炉的绝大部分区域内气利和固相的温度基本保持在还原煤气的入口温度．对高度为9．75m的Midrex竖炉，炉内绝大部分为浮氏体的还原，含铁原料运行约0．5m即可完全变成磁铁矿，运行约2m即可完全变成浮氏体．在竖炉7．0～9．75m深度范围内，随着还原气的上行，H2的体积分数迅速减少，而CO的体积分数变化不大．在竖炉2．0—7．0m深度范围内，H2和CO的体积分数缓慢降低，在竖炉0～2．0m深度范围内，H2和CO的体积分数显著降低．

Preliminary numerical process for simulation of shaft furnace DRI production

Based on mass and energy balances of gas and solid phases, a one-dimensional kinetic model of shaft furnace process for DRI production was developed. The model was able to satisfactorily reproduce the data from Gilmore Steel Corporation. The calculation results show that, the temperature difference between solid and gas is small in the most part of reduction section of MIDREX shaft furnace. For a shaft of 9. 75 meter height, the wustite reduction occurs in the lower part of 8.75 meter, while the hematite and magnetite reductions occur in the upper parts of 0. 5 meter and 2. 0 meter, respectively. In the lower part of 2. 75 meter, the hydrogen concentration decreases rapidly, while the carbon monoxide concentration variation is small. In the upper part of 2. 0 meter, the hydrogen and carbon monoxide concentrations decrease rapidly. In the rest part, the hydrogen and carbon monoxide concentrations decrease smoothly.