球团矿CO还原过程中微观结构的变化

MICROSTRUCTURE CHANGES OF THE IRON OXIDE PELLETS DURING THE CO REDUCTION PROCESS

根据高喷煤比的高炉多相流模拟研究数据,对球团矿进行CO还原反应实验,运用扫描电镜等手段对不同还原度的球团矿做微观结构分析,以探究不同还原阶段引起球团矿强度下降原因。微观结构分析表明,还原过程中从高价铁氧化物到低价铁氧化物变化过程中晶格的增大,新生铁相基体孔隙的增加、裂纹的产生以及渣铁分离等是导致强度下降的主要原因。

According to the study of transient mathematical model of blast furnace with high coal injection ratio based on multi - fluid concept, the reducing reaction was carried out on the iron oxide pellets. In the research, the microstructure changes of the iron oxide pellets with different reduction degrees were analyzed by the scanning electron microscope for exploring the reasons of compressive strength decrease of iron oxide pellets in different reducing stages. Microstructural analysis showed that the volume increase of lattice when high iron oxide was reduced into low iron oxide, the porosity increase of the fresh matrix iron phase, the generation of cracks and the separation of the iron and slag were the main reasons leading to the decrease of pellets compressive strength.