铁矿烧结过程微细颗粒物排放行为与控制技术研究

Iron ore sintering is the main source of PM10 and PM2.5 emissions in iron and steel industry. It is significant for the clearner production of iron and steel industry to reveal the characteristics and emission behaviors of PM10 and PM2.5 and develop the emission reduction technology of fine particulate matter (≤10μm). In this project, a new methodology of improving agglomeration of fine particulate matter by atomizing polymeric flocculant solution is put forward. The influences of formation and properties of fine particulate matter-polymeric flocculant-bridge polyphase interactions on agglomeration of fine particulate matter are studied by using the fundamentals and methods of surface chemistry, colloidal chemistry and ferrous metallurgy. The theoretical foundation of polymeric flocculant agglomerating fine particulate matter is established by researching adsorption properties and agglomeration behaviors between polymeric flocculant solution and fine particulate matter. By studying the influences of flocculant concentration, atomizing flow amount and flow rate of flue gas on flocculation efficiency, the key technology of PM10 and PM2.5 efficient emission reduction is developed, which will play a significant role in contributing the green and healthy development of iron and steel industry.

铁矿烧结是钢铁工业PM10和PM2.5的主要排放源。查明烧结过程PM10和PM2.5的物化特性及排放行为，开展烧结烟气微细颗粒物（≤10μm）减排基础研究，对我国钢铁工业清洁生产具有重要意义。本项目提出了高分子团聚剂强化烧结烟气中微细颗粒物团聚的学术思路，综合运用表面化学、胶体化学、钢铁冶金学等学科的基本理论与方法，研究烧结烟气微细颗粒物、高分子团聚剂、桥液多相界面上各种作用的产生、特性及其对微细颗粒物团聚的影响，阐述高分子团聚剂在微细颗粒物表面的吸附特性及微细颗粒物之间的团聚行为，揭示高分子团聚剂强化微细颗粒物团聚的理论基础；研究高分子团聚剂浓度、雾化流量、烟气流速等因素对烧结烟气中PM10和PM2.5团聚效率的影响，揭示强化烧结烟气中微细颗粒物团聚的作用机制，形成铁矿烧结PM10和PM2.5减排技术，为钢铁工业的绿色健康发展作出贡献。

针对铁矿烧结过程能耗高、污染严重等问题，开展了基于化学团聚铁矿烧结过程微细颗粒物减排研究。查明了烧结究烧结厂静电除尘器前后以及脱硫装置前后，烟气中 PM10 和 PM2.5 的排放浓度，经过电除尘后，90.47%的颗粒物为PM10，76.73%的颗粒物为PM2.5。从质量浓度上看，主要是2.5~10 μm的颗粒物；从数目浓度上看，主要是小于1 μm的颗粒物。微细颗粒物多呈规则的球形、长方体、片状，主要成分为KCl和NaCl。羟甲基纤维酸钠（CMC）、十二烷基苯磺酸钠（SDBS）和聚丙烯酰胺（PAM）三种高分子团聚剂均能改善与微细颗粒物的界面化学关系。在减小接触角方面，PAM溶液效果最好，SDBS溶液能有效降低与颗粒物的Zeta电位，CMC溶液的表面张力最低。系统研究了高分子团聚剂浓度、雾化流量、烟气流速等因素对烧结烟气中PM10和PM2.5团聚效率的影响，经过化学团聚烧结烟气PM10减排效率达65.9％，PM2.5减排效率达53.6％。本项目发表学术论文4篇，其中SCI/EI收录3篇；授权国家发明专利5项；参加国内外学术会议/学术报告6次；培养研究生2人，本科生2人，依托本项目指导本科生获“第二届冶金青年创新创意大赛”全国三等奖、“第七届挑战杯大学生课外学术科技作品竞赛”安徽省二等奖、“第十届全国大学生节能减排社会实践与科技竞赛”全国三等奖。