冶金工业废渣对燃煤助燃脱硝的影响

EFFECT OF METALLURGICAL INDUSTRY WASTE ON DENITRIFICATION AND COAL COMBUSTION

利用沉降炉燃烧系统,研究了五种冶金工业废渣对三种典型的烟煤燃尽率及氮氧化物释放的影响,并对添加剂的助燃机理进行了初步探讨.结果表明,煤种对于添加剂的催化性能起着重要作用,添加剂催化作用的大小和添加量有关,添加量并不是越大越好.在本实验范围内,钢渣适用于较低变质程度的烟煤;脱硫渣对于三种煤均有一定的催化助燃作用,但对于燃尽率的增幅都不是很大;锰尾矿适用于低变质程度的烟煤;铬渣适用于较高变质程度的烟煤.添加剂的加入能够影响煤中氮氧化物的释放,煤种和添加剂的添加量都能够对添加剂的脱硝效果起到重要的影响作用.通过对燃烧残余物的电镜扫描发现,加入废渣后燃烧产物颗粒外观由平整变为不规整的蜂窝状;此外,X射线衍射分析发现添加剂改变了燃烧残余物的组成.

In this paper, burn-off rate and nitrogen oxides release during three kinds of typical bituminous coals combustion with five kinds of metallurgical industrial wastes were studied by using laboratory-scale drop tube furnace combustion system, and the combustion mechanism was discussed. The results showed that the coal types played an important role in the catalytic properties, additive amounts could affect catalytic properties, additive amounts were not the bigger the better. In this work, steel slag was applicable for coal of lower metamorphic degree, desulfurization slag had certain catalytic combustion effects, manganese tailings were applicable for coal of low metamorphic degree and chromium slag was applicable for coal of higher degree of metamorphism. The additives could affect the release of nitrogen oxides, coal types and additives amounts had important influence on denitration effects. Based on the electron microscope scanning of combustion residue, it was found that the appearance of combustion residue with additives were like honeycomb, X-ray diffraction analysis showed that the additives changed the composition of the combustion residues.