再生铅冶炼烟气“SNCR+低温还原”脱硝工艺研究及生产实践

Research and production practice of "SNCR+low temperature reduction" denitration process for smelting flue gas of regenerated lead

富氧侧吹熔炼再生铅工艺目前成为国内再生铅冶炼的主流工艺,该工艺还原期阶段会产生大量NO_x,浓度可达1500 mg/Nm^3,需要选择合适的脱硝工艺对冶炼烟气进行处理。本文对SNCR、SCR、氧化吸收法和低温还原脱硝工艺的工艺原理、特点及使用条件进行了对比和分析,最终选择了"SNCR+低温还原"两级脱硝组合工艺,并对该工艺进行了实践应用,发现该工艺运行稳定,无二次污染,处理后的尾气氮氧化物含量降到100 mg/m^3以下,可达到国家排放标准。

Oxygen-enriched side blowing smelting process for regenerated lead has become the main process of regenerated lead smelting industry in China.During the reduction period of the process,a large amount of NO_x will be produced,and the concentration can reach 1500 mg/Nm^3.It is necessary to select a suitable denitration process to treat the smelting flue gas.In this paper,the process principle,characteristics and use conditions of SNCR,SCR,oxidation absorption method and low temperature reduction denitration processes are compared and analyzed.Finally,the"SNCR+low temperature reduction"two-stage denitration combination process was selected,and the process was applied.It was found that the process was stable and there was no secondary pollution.The nitrogen oxide content of the exhaust gas after treatment has been reduced below 100 mg/m^3,which meets the national emission standards.