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在自制的kg级高温流化床中研究了氢气还原1～3 mm矿粉的动力学试验。随着时间的增加,气体利用率下降,表明还原前期反应速度快,后期反应慢;温度越高,气体利用率越高,但随着还原时间的增加,差距在逐步缩小;对于750℃,前20 min的气体利用率为9%,金属化率达到84%,说明氢气还原矿粉反应是非常迅速的。随着气速的增加,金属化率在增加,并且几乎成线性关系,因此使用氢气作为还原剂,可以允许更高的气速,从而提高设备的生产效率。随着料高的增加,金属化率不断下降,然而气体利用率却在不断升高。使用氢气作为还原剂,可以将还原温度降低到700～750℃,避免流化床过程中的粘结难题;试验中氢气还原1～3 mm铁矿粉时的表观活化能为58.4kJ/mol。
The kinetics of hydrogen reduction of 1 ~ 3 mm ore powder was studied in a homemade kg high temperature fluidized bed. With the increase of time, the gas utilization rate decreased, indicating that the early reduction reaction speed, late slow reaction; the higher the temperature, the higher gas utilization, but with the reduction time increases, the gap is gradually reduced; for 750 ℃, before The gas utilization rate was 9% at 20 min and the metallization rate reached 84%, indicating that the hydrogen reduction of ground ore powder was very rapid. As the gas velocity increases, the metallization rate increases and is almost linear, so the use of hydrogen as a reductant allows for higher gas velocities, increasing the plant’s production efficiency. With the increase of the material height, the metallization rate has been declining, however, the gas utilization rate is continuously rising. Hydrogen as reductant can reduce the reduction temperature to 700-750 ℃ to avoid the problem of bond in the fluidized bed process. The apparent activation energy of hydrogen reduction of 1 ~ 3 mm iron ore powder is 58.4kJ / mol .