颗粒堆积多孔烧结床内嵌燃料的高效燃烧及CO控制机理

Based on the major demands of ultra-low emission and low carbon production in steel mills, this project focus on the sintering process, which is multi-phase porous bed combustion of solid quasi-fuel particles with complex embeded distributions. By using the single particle, lab-scale tablet, pilot-scale bed combustion tests and numerical computation and analysis, the influences of interface reactions of quasi-fuel and characteristics of porous channel on the carbon monoxide oxidation conversion mechanisms will be firstly investigated. In order to reduce primary carbon monoxide emission by more than 40%, the best match of multi-field parameters in sintering bed will be obtained by using multi-scale control methods including special quasi-particle design and porous phenomenon optimization. The main contents include: (1) quasi-fuel particle preparation and characterization of its physical and combustion properties; (2) the coupling mechanism of the effects of boundary atmosphere and transformation of iron oxides on the combustion efficiency; (3) the preparation methods to obtain the best packing structure parameters and boundary atmosphere for reducing high proportion of carbon monoxide; (4) the correlation mechanisms between combustion efficiency and performance indexes of the random heterogeneous sinter product. The research has important academic significance and application value not only for the combustion enhancement for complex porous structures, but also for energy conservation and emission reduction of the sintering industries.

面向钢铁行业超低排放和低碳生产重大需求，本项目针对烧结这一复杂内嵌固体燃料的多相多孔床层燃烧过程，通过单颗粒、实验室模拟柱、中试规模燃烧试验和数值计算分析等研究方法，在揭示内嵌燃料燃烧界面反应及多孔流道特性对CO氧化转化影响机理的基础上，采用内嵌颗粒构建和多孔效应优化的多尺度复合手段，获得烧结床层内多场参数的最佳匹配以实现燃烧源端CO排放减排40%以上。主要研究内容包括：（1）内嵌燃料制备与物理、燃烧特性综合表征；（2）边界氛围及铁氧化物转变对燃烧效率影响的耦合作用机制；（3）可高比例减排CO的最佳堆积结构参数和边界氛围构建方法；（4）燃料燃烧效率与随机非均质烧结成品综合性能的关联机制。研究结果对复杂多孔结构内燃烧强化进而实现烧结工业的节能减排具有重要的学术意义和应用价值。

铁矿石烧结是一种典型的内嵌燃料颗粒燃烧并伴有固相熔融烧结的多孔燃烧过程，燃烧现象和机理复杂，随着钢铁行业超低排放和低碳生产的要求日趋严格，近年来对烧结高效燃烧日益引起重视。本项目研究了燃料种类、内嵌形态、CuO-CeO2催化改性对内嵌燃料燃烧界面CO/CO2的生成规律，研究了烧结模拟柱高温熔融的形态和矿相转变，正交分析了烧结内嵌燃料生料堆积过程中水分、熟石灰、磁精矿等因素对于准颗粒强度、堆积床强度、堆积床透气性等指标的影响机制，在宽泛的参数条件下开展了烧结中试燃烧试验研究火焰锋面传播特性，进一步对烧结燃烧数值模型完善优化混合料堆积、熔融凝固等子过程并进行参数寻优，采用高分辨率XCT技术三维重建了烧结矿产品的多孔结构，基于真实结构分析了烧结矿的孔隙参数、应力强度及有效热导系数。项目成果探明了复杂内嵌燃料燃烧的界面反应动力学规律及其与铁氧化物转变的耦合协同机制，通过单颗粒、小型堆积床和中试规模多层次燃烧试验并结合数值模拟方法建立了结构参数、氛围调控和燃烧效率及烧结矿性能的关联机制，采用内嵌颗粒构建和多孔效应优化的多尺度复合手段，得以促进烧结过程燃烧效率提升及CO减排。参照项目计划书，已完成了项目任务，通过综合归纳整理试验及数值模拟数据，本项目已发表SCI论文8篇，申请发明专利1项，出版专著1部，达到了项目目标。