碱熔改性铁尾矿协同低温等离子体转化NO研究

The synergistic function of alkali modified iron tailings and nonthermal plasma on NO conversion

利用工业废弃物铁尾矿制备脱硝催化剂是实现其资源化利用的有效途径。本文利用碱熔改性铁尾矿与低温等离子体技术结合,研究其催化转化NO的性能。实验结果显示:KOH与铁尾矿质量比为1、焙烧温度为450℃条件下制备的改性铁尾矿效果最佳;优选条件下,反应器中添加碱熔改性铁尾矿后NO转化率最高可达88.0%,比空载、未改性铁尾矿和焙烧处理铁尾矿的转化率分别提高了42.0%、24.5%、14.7%,同时抑制了O_(2)对NO转化的负面作用;X射线衍射(XRD)、比表面与孔隙度分析(BET)、傅里叶变换红外光谱(FTIR)及X射线光电子能谱(XPS)等表征分析揭示,碱熔改性降低了铁尾矿的结晶度,增大了铁尾矿的比表面积和孔体积,增加了其表面吸附位点和吸附活性氧含量,从而有效提高等离子体环境中铁尾矿的催化活性。

Iron tailings can be used as catalysts for NO removal as useful resource.The synergistic function of alkali modified iron tailings combining with non-thermal plasma technology was investigated for NO conversion.The results showed that the modified iron tailings prepared with the mass ratio of KOH to iron tailings=1:1 and treated at 450℃ exhibited the best catalytic activity with the NO conversion up to 88.0%,which were 42.0%,24.5%,and 14.7%higher than the no-load,unmodified iron tailings and roasted treated iron tailings,respectively;meanwhile,the existence of modified iron tailings suppressed the negative effect of O_(2) on NO conversion.X-ray diffraction(XRD),Brunauer-Emmett-Teller(BET),Fourier-Transform infrared(FTIR)spectroscopy,and X-ray photoelectron spectroscopy(XPS)showed that the alkali modification reduced the crystallinity of iron tailings,increased the specific surface area,pore volume,surface adsorption sites and the content of adsorbed reactive oxygen species on the modified iron tailings,thus improving the catalytic activity of modified iron tailings in plasma environment.