针对不锈钢酸洗后混酸再生过程烟气的低流量、低温、高浓度氮氧化物、高腐蚀性的特点，采用选择性催化还原脱硝法，通过新颖的循环再热工艺设计，可以大大降低系统的再加热能耗，有效达到脱硝的效果，并分别讨论了烟气循环比、脱硝温度、氨气浓度及原始烟温等因素对该工艺的影响。

The flue gas generated in the regeneration process of mixed acids after pickling stainless steel has characteristics of low flow,low temperature,high concentration of nitrogen oxides (NO_x) and high corrosion.Therefore,it is effectively de-nitrated by the selective catalytic reduction (SCR) denitration technology and through a novel cycle reheating process design that can greatly reduce the energy consumption of re-heating system.In addition,the influences of flue gas recycle ratio,denitration temperature,ammonia concentration and initial flue gas temperature respectively on this technology is discussed.