碱度对镁质熔剂性球团矿强度的影响机理

Influence mechanism of basicity on strength of magnesium fluxed pellets

为探索碱度对镁质熔剂性球团矿强度的影响机理,以唐山某钢厂原料为基础,通过造球和焙烧试验,采用XRD、偏光显微镜、场发射扫描电镜分析和Matlab软件计算分析,分别从球团矿矿物组成、液相生成和微观结构、微观形貌和元素分布等方面深入分析了碱度对球团矿抗压强度的影响机理。研究表明,随着碱度升高,球团矿抗压强度呈升高趋势。球团矿中的主晶相为赤铁矿,液相主要由铁酸钙、硅酸钙和少量的石英组成,碱度高于0.8后出现了少量的铁酸镁。碱度升高,赤铁矿含量和液相量升高,致密度增大,气孔变均匀,使抗压强度增大。球团矿中Ca、Si、Mg 3种元素分布一致,Fe、O元素分布一致,且这两组元素分布呈互补关系。碱度提高,Ca、Si、Mg元素含量呈增加趋势,即液相量增加,球团矿抗压强度增大。两者的分析结果一致,并得到了相互印证。

To investigate the influence mechanism of basicity on the strength of magnesium fluxed pellets,based on the raw materials of a steel plant in Tangshan city,using pelleting and roasting experiment,with the help of XRD,polarized light microscope,field emission scanning electron microscope analysis and Matlab software calculation analysis,the mechanism of the influence of alkalinity on the compressive strength of pellets is analyzed in depth from the aspects of pellet mineral composition,liquid phase formation,and microstructure,micromorphology and element distribution.The results show that with the increase of basicity,the compressive strength of the pellets increases.Hematite is the main crystal in pellets.The liquid phase is mainly composed of calcium ferrite,calcium silicate,and a little quartz.After the basicity is higher than 0.8,a small amount of magnesium ferrite appears in pellets.As the basicity increasing,the hematite content and liquid phase content increase,density increases,the pore become more uniform,and compressive strength increases of pellets.The Ca,Si,and Mg have the same distribution,Fe and O have the same distribution,and the two groups of elements′distribution is complementary in pellets.As the basicity increases,the content of Ca,Si,and Mg elements increases,the content of the liquid phase increases,compressive strength increases of pellets.The analysis results of the two are consistent and have been mutually confirmed.