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对生物质松木锯末和烟煤还原焙烧高铁拜耳法赤泥进行对比试验研究,包括还原温度、还原时间、还原剂用量对还原效果的影响.生物质松木锯末还原高铁拜耳法赤泥所需还原温度低而且还原时间短最终还原效果较好.试验通过热分析和X射线衍射、动力学研究结果揭示出生物质松木锯末中低温还原高铁拜耳法赤泥机理.同时确定了生物质松木锯末中低温还原的最佳还原条件.研究表明生物质松木锯末为赤泥质量分数的20%,还原温度为650℃,还原时间为30 min可将赤泥完全磁化.生物质松木锯末热重试验分析表明250~375℃温度区间为锯末热解的主要阶段,350℃左右热解速率达到最大,450℃后热解反应趋于平缓;烟煤热重试验表明300~700℃温度区间为烟煤热解的主要阶段,450℃左右热解速率达到最大,650℃后热解反应趋于平缓.动力学研究表明锯末在300~400℃区间热解表观活化能比烟煤热解表观活化能要低很多,说明在此温度范围内锯末比烟煤更加容易发生热解反应.生物质能够中低温还原高铁拜耳法赤泥,还原温度比煤基还原的还原温度低200℃左右.
The effects of reduction temperature, reduction time and the amount of reductant on the reduction were compared between biomass pine wood sawdust and bituminous coal Bayer process red yeast.Reduce the reduction temperature And the reduction time is short and the final reduction effect is better.Through thermal analysis and X-ray diffraction, the kinetics study reveals the mechanism of low temperature reduction of Bayer red mud in biomass pine sawdust.At the same time, the least temperature reduction of biomass pine sawdust The results show that biomass pine sawdust is 20% of the mass fraction of red mud, the reduction temperature is 650 ℃, and the reduction time is 30 min, the red mud can be completely magnetized.The thermogravimetric analysis of biomass pine sawdust shows that 250 ~ 375 ℃ The temperature range is the main stage of sawdust pyrolysis. The pyrolysis rate reaches the maximum at 350 ℃, and the pyrolysis reaction tends to be gentle after 450 ℃. The thermogravimetric test shows that the temperature range of 300 ~ 700 ℃ is the main phase of pyrolysis of bituminous coal, The pyrolysis rate reached maximum at 650 ℃, and the pyrolysis reaction tended to be gentle. Kinetic studies showed that sawdust was pyrolyzed at 300 ~ 400 ℃ The apparent activation energy of coal pyrolysis is much lower than that of bituminous coal, indicating that sawdust is more prone to pyrolysis than bituminous coal in this temperature range. 200 ℃ or so.