烧结烟气脱硫脱硝用活性炭混合钢渣复合材料的光谱学分析

钢渣是冶金工业中产生的主要固体废弃物,其产量约为每年粗钢产量的15%~20%。由于技术的局限,导致我国钢渣利用率较低,仅为年钢渣产量的10%,同时加之管理制度的不健全,导致钢渣大量露天堆放,对土地资源、地下水源,以及空气质量形成严重影响。固体废弃物再利用是资源可持续发展的重要途径之一,钢渣的主要化学成分为CaO, SiO2, Al2O3, MgO, Fe2O3, MnO, f-CaO等。面对上述问题,利用冶金固体废弃物与活性炭开发一种价格低廉且性能优越的活性炭混合钢渣复合材料,既是冶金固体废弃物的高附加值利用与资源可持续发展的重要途径之一,也是大幅降低改性活性炭生产成本与提高经济效益的重要途径之一。该研究创新性以活性炭与钢渣为研究对象,利用钢渣中含有的金属氧化物对活性炭进行改性处理制备用于烧结烟气脱硫脱硝的活性炭混合钢渣复合材料,通过搭建实验反应装置对活性炭混合钢渣复合材料的脱硫脱硝性能进行测试。利用X射线荧光光谱仪(XRF)对钢渣的化学成分进行测试与分析,比表面积及孔径测定仪(BET)对活性炭混合钢渣复合材料的孔结构进行测试与分析,傅里叶变换红外光谱仪(FTIR)对钢渣的结构组成进行测试与分析,扫描电子显微镜(SEM)对活性炭混合钢渣复合材料的微观结构进行测试与分析,以揭示活性炭与钢渣制备活性炭混合钢渣复合材料的机理,以及活性炭混合钢渣复合材料对烧结烟气脱硫脱硝的机理。结果表明:当钢渣为电炉热泼渣、钢渣与活性炭质量比为2∶4、钢渣与活性炭细度为400目时,活性炭混合钢渣复合材料具有良好的脱硫脱硝性能与合理的经济性,即脱硫效率为100%、脱硝效率为58%。活性炭混合钢渣复合材料具有的多孔结构对SO2和NO进行有作用,钢渣中Fe2O3与MnO2促使活性炭官能团进行催化还原反应提高脱硫脱硝性能,其中吸附作用是主导与前提,催化还原反应是辅助与协同。以期为高附加值的钢渣利用提供新途径,实现钢铁企业以废治废、以废增效的目的。

Spectroscopic Analysis of Activated Carbon Mixed with Steel Slag Composite Material in Sintering Flue Gas of Desulfurization and Denitration

Steel slag tailings are the main solid waste in metallurgical industry, with the production of 15%~20% of crude steel. The utilization ratio is quite low and only reaches 10% of steel slag tailings production due to limited technology. Meanwhile, steel slag tailings are disposed in direct stacking and landfill in general since the management system is not perfect, which pollutes land source, underground water source and air quality. Recycling of solid waste is one important method to achieve sustainable development of resources. The main chemical compositions are CaO, SiO2, Al2O3, MgO, Fe2O3, MnO, f-CaO, etc. In the face of the above problems, the development of low price and superior performance of activated carbon mixed with steel slag composite material has become not only one of main methods to achieve the high value-added utilization of metallurgical solid waste and the sustainable development of resources, but also one of main methods to achieve the great reduction of the production cost of modified activated carbon and improve economic benefits. In this paper, activated carbon and steel slag were studied firstly, and activated carbon mixed with steel slag composite material for sintering flue gas of desulfurization and denitration was prepared by metal oxides contained in the steel slag were modified to treat the activated carbon, and desulfurization and denitration performance of activated carbon mixed with steel slag composite material was tested by setting up the experimental reaction device. Chemical component of steel slag was characterized and analyzed by X-ray fluorescence spectrometer(XRF), pore structure of activated carbon mixed with steel slag composite material was characterized and analyzed by specific surface area and pore size distribution analyzer(BET), composition structure of steel slag was characterized and analyzed by Fourier transform infrared spectrometer(FTIR) and microstructure of activated carbon mixed with steel slag composite material was characterized and analyzed by scanning electron microscope(SEM), so as to reveal the mechanism of preparing activated carbon mixed with steel slag composite material from activated carbon and steel slag, and the degradation mechanism of desulfurization and denitration in sintering flue gas by activated carbon mixed with steel slag composite material. The results show that the activated carbon mixed with steel slag composite material(steel slag is layer pouring slag from electric furnace, mass ratio of steel slag to activated carbon is 2:4 and fineness of steel slag and activated carbon is 400 mesh) has good properties of desulfurization and denitration and reasonable economy with desulfurization efficiency of 100% and denitration efficiency of 58%. The porous structure of activated carbon mixed with steel slag composite material adsorbed SO2 and NO, and Fe2O3 and MnO2 in steel slag promote the catalytic reduction reaction of activated carbon functional groups to improve the properties of desulfurization and denitration, where adsorption is the leading and prerequisite, and catalytic reduction reaction is auxiliary and synergistic. It aims to provide a new way for the utilization of high value-added steel slag, and achieve the target of waste management waste and waste to increase efficiency in iron and steel enterprise.