氢气还原褐铁矿实验研究与动力学分析

Experimental research and kinetics analysis on hydrogen reduction of limonite

本文旨在研究不同温度下氢气对褐铁矿还原度和还原速率的影响,并以此为基础分析动力学相关问题.通过热重分析深入了解褐铁矿失水状况.使用粒度为8~12 mm褐铁矿焙烧后,分别在750~950℃五个不同温度下使用4 L·min-1 H2进行还原,并分析还原率和还原速率随时间的变化关系.研究发现：随着反应进行,试样还原率逐渐增大,五条还原率曲线在t〉28 min后与还原温度排序一致.通过动力学研究计算得反应表观活化能E=15.323 kJ·mol-1,从而确定扩散为还原反应的限制环节.

This article presents experimental studies on the effects of H2 on the reduction degree and rate of limonite at different temperatures and kinetic analysis during the hydrogen reduction. The water loss of limonite was investigated by thermal gravimetric analysis. Limonite of 8 to 12 mm in granularity was reduced with 4 L·min-1 H2 at five temperatures of 750 to 950℃. As the reduction reaction proceeded, the reduction degree increased, and the sequence of 5 reduction degree curves was consistent with that of reaction temperature when t〉28 min. The apparent activation energy was kinetically calculated to be 15. 323 kJ·mol-1 , so diffusion is the re-strictive step of the reduction reaction.