Abstract：Under the situation of resource constraint and environmental protection pressure, in the new period, the key point of pelletizing environmental protection is to reduce NOx emission, and its efficient control is related to the survival of pelletizing industry. Taking iron ore pellets as the object, the effect of temperature on denitrification of different iron concentrate pellets was studied. On this basis,the catalytic denitrification reaction behavior of the down-draft drying section (DDD section) of the grating machine was studied and the influence rule of flue gas composition on denitrification in DDD section was characterized by denitrification rate and ammonia utilization, etc. The results show that the catalytic performance of hematite is better than that of magnetite and mixed ore, at the same time, the characteristics of the temperature distribution in each section of the grate machine are analyzed, and the DDD section is finally selected as the reaction zone for SCR denitration.and the optimum denitration conditions are as follows, temperature is 300-350 ℃; the volume percent of oxygen is 15%-20%, the molar ratio ammonia to nitrogen is 0.5; when SCR denitrification is carried out in the grate down-draft drying section, the volume percent of SO2 in the flue gas is increased from 0 to 0.050%, and the reaction denitrification rate is reduced from 51.0% to 34.4%; with the increase of the water vapor(volume percent) in the flue gas, the reaction denitration rate decreases, when the water vapor(volume percent) is 9%, the denitration rate is only 44.9%. Generally speaking, the denitrification rate of about 40% can be obtained by controlling volume percent of SO2 0.040% and the water vapor(volume percent) is less than 6%. The denitration rate is highly effective and feasible in the DDD section of the ammonia spray catalytic denitration method.
甘敏, 朱亮, 范晓慧, 季志云, 孙增青, 郑浩翔. 链箅机铁矿球团料层催化脱硝的反应行为及影响因素[J]. 钢铁, 2021, 56(12): 36-42.
GAN Min, ZHU Liang, FAN Xiao-hui, JI Zhi-yun, SUN Zeng-qing, ZHENG Hao-xiang. Reaction behavior and influencing factors of catalytic denitration of iron ore pellets in chain grate[J]. Iron and Steel, 2021, 56(12): 36-42.
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