CO气氛下稀土尾矿的催化脱硝特性研究

Research on Catalytic Denitrification Performance of Rare Earth Tailings in CO Atmosphere

对白云鄂博稀土尾矿的催化脱硝性能进行了研究。结果表明:该稀土尾矿具有良好的催化脱硝性能;随着温度的升高和碳氮比的增大,尾矿的脱硝效率明显提升,当碳氮比为4∶1、温度为900℃时,未焙烧尾矿催化下NO转化率高达97%。稀土尾矿中的Fe元素主要以Fe2O3和Fe3O4形式存在,在尾矿催化CO还原NO过程中,Fe元素向低价态转变;Fe类物质的增多以及多种物质的协同作用均可提高尾矿的催化脱硝活性。天然尾矿中含有大量的Ce^3+;在CO还原气氛下,尾矿中Ce^3+含量进一步增加,提高了尾矿的脱硝性能。程序升温还原实验结果表明尾矿具有优异的还原能力。

The catalytic denitrification performance of Bayan Obo rare earth tailings was studied.The results show that the rare earth tailings have good catalytic denitration performance.With the increase of reaction temperature and carbon to nitrogen ratio,denitration efficiency of the tailings obviously increases.When carbon to nitrogen ratio is 4∶1 and temperature is 900 ℃,NO conversion rate with catalysis of un-calcined tailings reaches 97%.Fe element in the rare earth tailings exists mainly in the form of Fe2O3 and Fe3O4,and Fe element changes to a low-valent state during CO reduction of NO catalyzed by the tailings.The increase of Fe-containing substances and the synergistic effect of various substances can enhance the catalytic denitration activity of the tailings.The natural tailings contain a large amount of Ce^3+,and the amount further increases in CO reducing atmosphere to improve denitrification ability of the tailings.Temperature-programmed reduction experimental results show that the tailings have excellent reducing ability.