冶金尘泥多组分团聚效应对燃煤细颗粒物（PM2.5）协同抑制行为的研究

Coal-firing is one of the major sources of PM2.5, and the source control by adding metallurgical sludge including Fe2O3, CaO, MgO, Al2O3 and SiO2 (FCMAS system ) is significant to the reduction of PM2.5 in the atmosphere. Our previous study found that the agglomeration effect of FCMAS system reacting with PM2.5 precursor can reduce PM2.5 emissions from coal-fired. However, their synergistic effect on inhibition of PM2.5 has seldom been reported. Therefore, the study of FCMAS system as PM2.5 inhibitors is proposed here and focused on the two respects：① the effects of the different components of FCMAS system on the migration, conversion and adsorption of harmful heavy metals in coal，exploring the mechanism of polymerization and growth of hazardous metal and easy-gasification alkali metals. ② investigating the reaction between the various contents of FCMAS system and aluminosilicate in coal，which are easy to combine and form compounds and then to establish the forecasting model of PM2.5. This study focuses on exploring the mechanism of the enrichment and agglomeration mechanism of harmful metals by adding FCMAS system to coals in order to reduce PM2.5 emissions from coal-fired processing. The expected results swill provide the theoretical basis for metallurgical solid waste utilization and emission reduction of coal pollutions. ..

燃煤是大气中PM2.5的主要来源之一，利用冶金尘泥中主要组分Fe2O3、CaO、MgO、Al2O3、SiO2（简称FCMAS体系）从源头抑制PM2.5的生成具有重要意义。申请者在研究中发现，FCMAS体系中多组分与燃煤排放的PM2.5前驱体发生交互作用产生团聚效应，从而降低燃煤PM2.5的排放，而类似这种“以废治污”的研究在此领域少见报道。故此，提出以FCMAS体系作为燃煤PM2.5抑制剂的研究思路，重点研究：①FCMAS体系中不同组分对煤中有害重金属元素的迁移转化和吸附过程的影响，探索有害金属富集规律及易气化碱金属的聚合长大机制，② 查明FCMAS体系中多组分与煤中硅铝酸盐等易成核组分协同反应生成低温共熔体的作用机理，从而解决：“FCMAS体系多组分对燃煤有害金属富集及团聚的作用机制”这一关键科学问题，并建立燃煤PM2.5的预测模型，预期成果为冶金固废综合利用和降低燃煤污染提供理论依据。

基于冶金尘泥组分复杂难以高附加值利用，结合目前燃煤释放PM2.5造成严重的环境污染的现状，项目通过模拟冶金尘泥中主要组分（简称FCMAS体系）特性，并参与燃煤燃烧，研究其从源头抑制PM2.5的生成及排放机理，发现FCMAS体系添加剂在混合料中的配比对燃煤PM2.5生成及排放的影响较为明显；尤其随着尘泥加入量的增加，PM2.5的释放比例明显降低，较大粒径颗粒排放比例增加，为后续除尘提供了有力条件；FCMAS体系中各组分与煤炭中易挥发成核物质发生物化反应，生成较大粒径颗粒，且与煤炭灰分中硅酸盐在燃烧过程中，发生交互作用生成多相低温共熔化合物，从而降低了微小颗粒物成核元素的释放；此外通过研究FCMAS体系与煤炭燃烧过程中释放的痕量有害重金属（Hg、Cd、Pd、Se、Cr、As等）吸附富集的内在关系及对不同粒度颗粒的贡献，揭示了冶金尘泥各组分协同煤炭中矿物组分之间的交互作用及团聚效应降低重金属排放的作用规律，并建立了混煤燃烧颗粒物排放的预测模型，尘泥影响PM2.5排放的相关系数达到90%以上。本项目的顺利实施，不仅为冶金尘泥中多组分协同利用提供了理论指导，也为抑制燃煤PM2.5生成及降低粉尘排放提供研究基础，从而实现以废治污的环保宗旨。