烧结烟气是钢铁工业污染物的最大排放源，现阶段冶金脱硫除尘工艺逐渐成熟，但NOx的脱除仍处于起步阶段，部分企业存在NO_x排放超标现象，随着环保指标进一步提高，优化NO_x治理工艺，降低冶金烟气中NOx排放成为钢铁行业污染治理的重中之重，应当给予更多重视。介绍了烧结过程中N的作用机理，其中挥发性氮参与氧化还原反应，高温低氧条件促进还原反应生成N₂，抑制NO_x生成，同时高温促进焦炭氮吸附及异相还原反应；总结烧结烟气特点，其成分较为复杂、污染物含量高、含水量和含氧量大、烟气温度较低导致对SCR催化剂温度窗口要求较低，这些特点进一步制约烧结烟气治理的发展；对比分析了当前几种典型脱硝工艺及烧结烟气脱硝技术存在的问题，SCR脱硝法为当前主流脱硝工艺，催化剂的催化活性组分和性能是该技术的核心和关键，也是近年来的研究热点，指出稀土改性含铁尘泥γ-Fe₂O₃新型铁基低温催化剂是确实可行的脱硝催化剂研究方向，具有抗碱金属中毒、低温催化活性好、经济可靠等特点，并可进一步扩大冶金资源利用范围；展望了脱硝发展方向和新工艺，等离子脱硝和微生物脱硝研究起步相对较晚，但由于其受烟气温度影响较小可达到较好脱硝效果，具备优异发展前景，但存在若干问题未实现工程应用；改善工艺如引进烟气再循环、空气分级燃烧、低氧燃烧等燃烧中控制技术，通过优化烧结混合料结构如强化制粒效果、厚料层高碱度烧结等可协调烧结后烟气脱硝工艺，降低烟气NO_x排放浓度；分级治理烧结烟气存在投资运行费用高、占地面积大等缺点，开发可靠经济高效的脱硫脱硝一体化工艺具有重要意义，脱硫工艺耦合SCR脱硝是烧结烟气污染物治理发展的重要方向；通过参考脱硫脱硝新技术和新思路，提出烟气再循环+CO催化氧化+SCR脱硝+CFB/SDA脱硫的工艺流程，可为钢铁厂脱硝技术研究及发展提供参考。

Sintering flue gas is the largest emission source of pollutants in the iron and steel industry. At this stage，the metallurgical desulfurization and dust removal process is gradually mature，but the removal of NO_x is still in its infancy. Some enterprises have excessive NOx emissions. With the further improvement of environmental protection indicators，optimizing NO_x treatment process，reducing NOx emissions in metallurgical flue gas has become the top priority of pollution treatment in the iron and steel industry，which should be paid more attention. The mechanism of N in the sintering process was introduced. Volatile nitrogen participates in the redox reaction. The high temperature and low oxygen conditions promote the reduction reaction to generate N₂ and inhibit the formation of NO_x. At the same time，high temperature promotes the coke nitrogen adsorption capacity and heterogeneous reduction reaction;The characteristics of sintering flue gas were summarized. Its composition is more complex，the content of pollutants is high，the water content and the oxygen content are large，and the lower flue gas temperature leads to lower requirements for the temperature window of the SCR catalyst. These features further restrict the development of sintering flue gas treatment;The existing problems of current several typical denitrification processes and sintering flue gas denitrification technology were compared and analyzed. SCR denitration method is the current mainstream denitration process. The catalytic active components and performance of the catalyst are the core and key of the technology，and it is also a research hotspot in recent years. The new iron-based low-temperature catalyst of γ-Fe₂O₃ containing iron-containing dust is a feasible research direction of denitration catalyst，which has the characteristics of resistance to alkali metal poisoning，good low-temperature catalytic activity，and economical reliability and can further expand the scope of metallurgical resources utilization;The development direction and new technology of denitration were prospected. The research of plasma denitrification and microbial denitrification started relatively late，but due to its smaller effects of flue gas temperature，it can achieve better denitrification effect and has excellent development prospects，but there are several problems that have not been applied in engineering;Improved technology such as the introduction of flue gas recirculation，air staging combustion，low-oxygen combustion and other combustion control technologies can coordinate the flue gas denitration process after sintering by optimizing the structure of the sintering mixture，such as enhanced granulation effect，thick material layer and high basicity sintering，etc. Flue gas NOx emission concentration;The hierarchical treatment of sintering flue gas has disadvantages such as high investment and operation cost and large area. It is of great significance to develop a reliable，cost-effective and integrated desulfurization and denitrification process. The desulfurization process coupled with SCR denitrification is an important direction for the treatment of sintering flue gas pollutants. By referring to the recent research on some new desulfurization and denitrification technologies and new ideas，the process flow of flue gas recirculation + CO catalytic oxidation + SCR denitrification + CFB/SDA desulfurization is put forward，which can provide some reference for the research and development of denitrification technology in steel works.

0 引言

1 烧结烟气概述

   1.1 烧结烟气中NO_x生成机理

   1.2 烧结烟气特点

2 现阶段主要烧结烟气脱硝技术

   2.1 选择性催化还原法(SCR)与选择性非催化还原法(SNCR)

   2.2 活性焦吸附法

   2.3 臭氧氧化法

3 适用于烧结烟气脱硝的新技术

   3.1 等离子体法

   3.2 微生物脱硝法

4 结语与展望