工程科学学报，第39卷，第9期：1331-1338,2017年9月 Chinese Journal of Engineering,Vol.39,No.9:1331-1338,September 2017 D0l:10.13374/j.issn2095-9389.2017.09.005:;htp:/journals..ustb.edu.cn 生物质松木锯末中低温还原高铁拜耳法赤泥 李恒，刘晓明⑧，赵喜彬，陈蛟龙，尹海峰 北京科技大学治金与生态工程学院，北京100083 ☒通信作者，E-mail:lium@usth.edu.cn 摘要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30mi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. 关键词生物质：烟煤：高铁拜耳法赤泥：焙烧：热解 分类号TG142.71 Medium-low temperature reduction of high-iron Bayer process red mud using biomass pine sawdust LI Heng,LIU Xiao-ming,ZHAO Xi-bin,CHEN Jiao-long,YIN Hai-feng School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083.China Corresponding author,E-mail:liuxm@ustb.edu.cn ABSTRACT An experiment was conducted to determine the difference between using biomass pine sawdust and pulverized coal in the reduction roasting of high-iron Bayer process red mud from the perspective of reduction temperature,reduction time,and reducing agent dosage.Experimental results show that biomass pine sawdust reduction roasting is quicker,occurs at a lower temperature,and is a superior process to pulverized coal reduction roasting.The mechanism of using biomass pine sawdust in reduction roasting of high-i- ron Bayer process red mud at a low temperature was investigated using thermal analysis,X-ray diffraction,and dynamic analysis.In addition,the optimum conditions involved in reducing high-iron Bayer process red mud were determined using biomass pine sawdust at medium and low temperatures.It is found that when using 20%biomass pine sawdust in mass at a reduction temperature of 650C and a reduction time of 30 min,the high-iron red mud in the Bayer process can be completely magnetized.A thermogravimetric experiment conducted on biomass pine sawdust indicates that the main stage of sawdust pyrolysis occurs within a temperature range of 250-375C. The pyrolysis rate reaches a maximum at about 350 C,but tends to be gentle at 450 C.The main stage of pulverized coal pyrolysis oc- curs at 300-700C;the pyrolysis rate is at its maximum at 450 C but it tends to be gentle at 650C.The kinetic study shows that at a temperature of 300-400C,the apparent pyrolysis activation energy of the sawdust is much lower than that of pulverized coal,indi- cating that sawdust is more prone to pyrolysis than pulverized coal at this temperature range.In summary,biomass reduces high-iron 收稿日期：2017-04-11 基金项目：国家自然科学基金资助项目(51574024)：中央高校基本科研业务费专项资金资助项目(FRF-BR-16-026A):中国博士后科学基金 资助项目(2015M580987,2016T90034)工程科学学报,第 39 卷,第 9 期:1331鄄鄄1338,2017 年 9 月 Chinese Journal of Engineering, Vol. 39, No. 9: 1331鄄鄄1338, September 2017 DOI: 10. 13374 / j. issn2095鄄鄄9389. 2017. 09. 005; http: / / journals. ustb. edu. cn 生物质松木锯末中低温还原高铁拜耳法赤泥 李 恒, 刘晓明苣 , 赵喜彬, 陈蛟龙, 尹海峰 北京科技大学冶金与生态工程学院, 北京 100083 苣通信作者,E鄄mail:liuxm@ ustb. edu. cn 收稿日期: 2017鄄鄄04鄄鄄11 基金项目: 国家自然科学基金资助项目(51574024);中央高校基本科研业务费专项资金资助项目(FRF鄄鄄BR鄄鄄16鄄鄄026A);中国博士后科学基金 资助项目(2015M580987, 2016T90034) 摘 要 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 益 ,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 益温度区间为锯末热解的主要阶段,350 益 左右热解速率达到最大, 450 益后热解反应趋于平缓;烟煤热重试验表明 300 ~ 700 益温度区间为烟煤热解的主要阶段,450 益左右热解速率达到最大, 650 益后热解反应趋于平缓. 动力学研究表明锯末在 300 ~ 400 益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 益左右. 关键词 生物质; 烟煤; 高铁拜耳法赤泥; 焙烧; 热解 分类号 TG142郾 71 Medium鄄low temperature reduction of high鄄iron Bayer process red mud using biomass pine sawdust LI Heng, LIU Xiao鄄ming 苣 , ZHAO Xi鄄bin, CHEN Jiao鄄long, YIN Hai鄄feng School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China 苣Corresponding author, E鄄mail: liuxm@ ustb. edu. cn ABSTRACT An experiment was conducted to determine the difference between using biomass pine sawdust and pulverized coal in the reduction roasting of high鄄iron Bayer process red mud from the perspective of reduction temperature, reduction time, and reducing agent dosage. Experimental results show that biomass pine sawdust reduction roasting is quicker, occurs at a lower temperature, and is a superior process to pulverized coal reduction roasting. The mechanism of using biomass pine sawdust in reduction roasting of high鄄i鄄 ron Bayer process red mud at a low temperature was investigated using thermal analysis, X鄄ray diffraction, and dynamic analysis. In addition, the optimum conditions involved in reducing high鄄iron Bayer process red mud were determined using biomass pine sawdust at medium and low temperatures. It is found that when using 20% biomass pine sawdust in mass at a reduction temperature of 650 益 and a reduction time of 30 min, the high鄄iron red mud in the Bayer process can be completely magnetized. A thermogravimetric experiment conducted on biomass pine sawdust indicates that the main stage of sawdust pyrolysis occurs within a temperature range of 250鄄鄄375 益 . The pyrolysis rate reaches a maximum at about 350 益 , but tends to be gentle at 450 益 . The main stage of pulverized coal pyrolysis oc鄄 curs at 300鄄鄄700 益 ; the pyrolysis rate is at its maximum at 450 益 but it tends to be gentle at 650 益 . The kinetic study shows that at a temperature of 300鄄鄄400 益 , the apparent pyrolysis activation energy of the sawdust is much lower than that of pulverized coal, indi鄄 cating that sawdust is more prone to pyrolysis than pulverized coal at this temperature range. In summary, biomass reduces high鄄iron