PDF《博士学位论文公示材料》

在过湿层由于温度较低,料层基本不产生 SO2 和NOx,由于循环烟气中污染物浓度较 常规烧结污染物浓度高,料层中熔剂会吸附烟气中更多的 SO2,减少烟气中 SO2 的排放,对烟气中 NOx 排放无影响.通过比较不同烧结条件下烟气污染物排放曲线,由于循环条件下烟气污染物含量高,因 此烟气污染物排放量较高,但是被料层吸附及还原的烟气污染物含量也随之升高;

当利用锯末炭做烧 结燃料时,锯末炭中的硫和氮含量较低,因此在烧结过程中锯末炭产生的烟气污染物 SO2 和NOx 均低 于焦粉,能够实现烧结烟气污染物源头管控. (3)基于生物质燃料烟气循环烧结污染物协同控制污染物研究:基于优化烧结配料条件,选用改 性锯末炭替代部分焦粉进行烟气循环烧结杯实验,分别研究循环烟气含氧量、温度、SO2 含量和 NOx 含量对生物质燃料烧结成矿性能和烟气污染物排放规律的影响,同时对烟气循环条件下改性锯末炭的 ―2― 适宜替代量进行了研究.实验结果表明:基于改性锯末炭替代焦粉进行烟气循环烧结,适宜烟气含氧 量为 14.9%,循环烟气中 SO2 浓度不应高于 500ppm,NOx 对烧结性能指标影响较小,烟气含 NOx 浓度 越高,烟气中 NOx 减排量越大.在烟气温度为 200℃和CO 含量为 0.85%的条件下进行循环烧结,在保 证烧结成矿性能的前提下,改性锯末炭替代焦粉含量由 40%提高到 50%,烧结烟气污染物 SO2 和NOx 分别相对减排 42.6%和65.8%以上,减少烧结烟气末端处理量,实现烧结烟气余热利用和烟气污染物协 同控制目标. 论文摘要(英文) The iron and steel industry is one of the key industries supporting the development of the national economy, in addition to being a resource- and energy-intensive industry that produces high levels of pollution. The high levels of energy consumption, resource consumption, and environmental load have become the bottleneck restraining factors related to upgrading and sustainable development in the industry. Reducing the emissions of sintering flue gas pollutants is the top priority related to air pollution control in the iron and steel industry. In the face of increasingly stringent environmental protection policies, it is difficult to meet the emission requirements for flue gas pollutants with a single flue gas pollutant terminal treatment. In this paper, the results of research on both source control of pollutants from biomass fuel and process control via circulating sintering flue gas are presented, in accordance with the concept of synergistic treatment of the whole sintering process. In addition, potential options for using existing terminal treatment technology for sintering flue gas pollutants to realize the synergistic treatment of pollutants are presented. (1) Study on replacing coke with biomass fuel for sintering: Comparing industrial analysis, calorific value and pore structure of three biomass fuels (sawdust, peanut hulls, and corn stalks) with bituminous coal and coke powder. Biomass fuels are typically characterized by low fixed carbon contents, low calorific values, loose and porous interiors, large specific surface areas, and good fuel reaction performances. In view of such fuels having low calorific values and reaction rates that were too fast, briquetting and carbonization experiments o........