摘要
针对稀土尾矿催化CO还原NO进行实验研究。实验结果表明,稀土尾矿能有效催化还原NO,且脱硝率随着反应温度的升高和碳氮比的增加而增加。稀土尾矿在中高温段的脱硝率高于纯物质CeO2、Fe2O3、Fe2O3/CeO2和5Fe2O3/CeO2;H2-TPR测试表明,稀土尾矿在800℃以上出现的还原峰也高于这4种纯物质。XRD分析表明稀土尾矿的主要矿相在脱硝反应前后没有变化,但各矿相特征峰的强度下降,氟碳铈矿特征峰消失。SEM图像显示脱硝反应后稀土尾矿中出现裂缝和孔隙。EDS分析表明,稀土尾矿单一颗粒中存在多种金属元素的重叠区。XPS分析结果表明稀土尾矿脱硝后Fe3+和Ce3+的比例增加。当反应温度为900℃,碳氮比为4∶1时,稀土尾矿的脱硝率为98%。
Experimental study was conducted on the reduction of NO,using CO as the reductant and rare earth tailings as the catalyst.The experimental results show that rare earth tailings can effectively catalyze the reduction of NO,and the denitration rate increases as the reaction temperature and the carbon-to-nitrogen ratio increase.The denitration rate of rare earth tailings in the middle and high temperature section is higher than that of the pure substances of CeO2,Fe2O3,Fe2O3/CeO2 and 5 Fe2O3/CeO2.H2-TPR test shows that the reduction peaks of rare earth tailings above 800℃are also higher than those of the four pure substances.XRD analysis shows that the main mineral phases of the rare earth tailings have no change before and after denitration reaction.However,the intensity of characteristic peaks of each mineral phase decreases,and the characteristic peak of bastnaesite disappears.SEM images show that cracks and pores appear in rare earth tailings after denitration reaction.EDS analysis shows that there are overlapping areas of multiple metal elements in a single particle of tailings.XPS analysis shows that the proportions of Fe3+and Ce3+in the tailings increase after denitration reaction.When the reaction temperature is 800℃and the carbon-to-nitrogen ratio is 4∶1,the denitration rate is 98%by rare earth tailings.
作者
王建
龚志军
孟昭磊
崔梦壳
武文斐
WANG Jian;GONG Zhi-jun;MENG Zhao-lei;CUI Meng-ke;WU Wen-fei(School of Environment&Energy,Inner Mongolia University of Science&Technology,Baotou 014010,China;Key Laboratory of High Efficiency and Clean Combustion in Inner Mongolia Autonomous Region,Baotou 014010,China)
出处
《稀有金属与硬质合金》
CAS
CSCD
北大核心
2020年第3期38-44,72,共8页
Rare Metals and Cemented Carbides
基金
国家自然科学基金(51866013)
内蒙古自治区自然科学基金(2017MS(LH)0529)。
