宝钢烧结烟气超低排放技术集成与实践

Technology integration and practice of ultra-low emission of sintering flue gas in Baosteel

为了满足钢铁行业超低排放标准,在源头控制和过程减排基础上,宝钢烧结采用了两条末端协同治理工艺路径,即四电场静电除尘+活性炭二级吸附法、四电场静电除尘+CFB脱硫+SCR脱硝的协同净化法,从而建立烧结烟气全流程超低排放技术集成。对上述两种工艺的装备、减排效果及运行成本等进行了系统分析。结果表明,两种工艺的SO2排放质量浓度均低于20mg/m^3(标准态)的标准,且具备NOx排放质量浓度不高于50mg/m^3(标准态)超低排放限值的潜力,但难以稳定达到颗粒物排放低于10mg/m^3(标准态)限值的要求。活性炭二级吸附法副产物回收利用率高,协同净化法的脱硫灰发生量较大,且需付费处置。在投资额与综合成本方面,活性炭二级吸附法均高于协同净化法,而在不含折旧运行成本及直接成本方面则相反。协同净化法的折算吨矿工序能耗显著高于活性炭二级吸附法。基于环保税额分析单位污染当量数脱除和排放费用,便于统筹考虑生产和环保设施的协同运行。

In order to meet the ultra-low emission standard of iron and steel industry,based on the source control and emission reduction technology,the sintering process of Baosteel adopts two co-purification processes,including fourelectric field electrostatic precipitation and two-level activated carbon adsorption method,and four-electric field electrostatic precipitation and CFB desulfurization plus SCR denitrification method.The equipment,emission reduction effect and operation cost of the two processes are systematically analyzed.The results show that SO2emission concentration of both processes can lower than 20mg/m^3(standard state),and can be potential to meet NOxultra-low emission limits lower than 50mg/m^3(standard state),but it is difficult to reach the requirement that the emission limits of particulate matter lower than 10mg/m^3(standard state).The by-product recovery rate of two-level activated carbon adsorption is high.While the synergistic purification process will produce a large amount of desulfurization ash,resulting in extra disposal.In terms of investment and comprehensive cost,the two-level activated carbon adsorption method is higher than the synergistic purification method,but if depreciation operation cost and direct cost are not considered,the result is just opposite.The energy consumption of the converted ton sinter of the synergistic purification method is significantly higher than that of the two-level activated carbon secondary adsorption method.Based on the analysis of environmental protection tax amount,the unit pollution equivalent removal and emission cost,producing and environmental protection facilities should be considered as a whole cooperate.