NOx Emission Reduction by Advanced Reburning in Grate-Rotary Kiln for the Iron Ore Pelletizing Production

Processes

Peiwei Hu¹  Zhicheng Xie¹  Gangli Cheng¹  Liu Liu¹  Jiaoyang Wei¹  Bing Hu²  Biao Lu³ 

[1] College of Resources and Environment Engineering, Wuhan University of Science and Technology, Wuhan 430081, China;National Engineering Research Center of Sintering and Pelletizing Equipment System, Zhongye Changtian International Engineering Co., Ltd., Changsha 410205, China;School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, China;

关键词: advanced reburning;    denitrification;    grate-rotary kiln;    NO_x reduction;   

DOI  :  10.3390/pr8111470

来源: DOAJ

【 摘 要 】

The NO_x reduction in the iron ore pelletizing process becomes an important environmental concern owing to its role in the formation of photochemical smog and acid rain. Thus, it is essential to develop new technologies for reducing NO_x emissions in order to contribute to the cleaner production of pellets. In this paper, NO_x reduction by advanced reburning ingrate-rotary kiln for oxidized pellet production was performed on a laboratory-scale gas kiln. Temperature and NH₃/NO_x molar ratio (NSR) were the key factors affecting the reduction of NO_x. A better denitrification effect can be obtained on flus gas with higher initial NO_x concentration, at temperature = 900 °C, NSR = 1.2, and reaction time exceeds one second. NO_x reduction rate had reached 55–65% when the initial NO_x concentration was above 400 ppm, and exceeds 70% when the initial NO_x concentration was around 680 ppm. Urea solution has the best denitrification effect compared with NH₃·H₂O and NH₄HCO₃ solution. As for additives, the denitrification effect of the vanadium-titanium catalyst was better than that of ethanol and NaCl, while NaCl plays a promotive role at low NSR. Finally, a series of denitrification measures that include advanced reburning technology for achieving NO_x ultra-low emission in the oxidation pellet production was proposed.

【 授权许可】

Unknown