高硅超细铁精矿熔剂性球团矿固结行为及还原特性  

Consolidification behavior and reduction characteristics of high-silicon ultrafine magnetite concentrate fluxed pellets

作　　者：温宝良 范子豪 李家新 刘德楼 从俊强 杨佳龙 WEN Baoliang;FAN Zihao;LI Jiaxin;LIU Delou;CHONG Junqiang;YANG Jialong(School of Metallurgical Engineering,Anhui University of Technology,Maanshan 243032,Anhui,China;Technical Center,Fushun New Steel Co.,Ltd.,Fushun 113001,Liaoning,China)

机构地区：[1]安徽工业大学冶金工程学院,安徽马鞍山243032 [2]抚顺新钢铁有限责任公司技术中心,辽宁抚顺113001

出　　处：《钢铁》2024年第5期33-44,共12页Iron and Steel

基　　金：国家自然科学基金资助项目(U1860113)。

摘　　要：高炉高比例球团矿冶炼技术是减轻炼铁系统碳排放和环保压力的重要方案。将高硅超细铁精矿资源作为球团矿生产原料,有助于拓宽中国国内铁矿资源来源,加大中国国内贫矿应用力度。系统地探讨了碱度对高硅超细铁精矿球团矿固结行为和还原特性的影响。通过热力学计算、矿相分析、扫描电镜-能谱分析等方法对其固结行为和还原特性进行了研究。研究结果表明,随着碱度的增加,高硅超细铁精矿球团矿抗压强度先增加后降低,孔隙率先降低后增加,碱度为0.06~0.73时,球团矿的抗压强度均大于4000 N/个,碱度为0.24时的球团矿抗压强度最高,孔隙率也最低。碱度的增加会降低高硅超细铁精矿球团矿中的二氧化硅相含量,促进铁酸钙相和硅酸盐相的生成。在碱度为1.20、温度为1300℃条件下,球团矿中液相比例可达24.38%。碱度大于0.73时,球团矿中的液相量在大于1250℃后会迅速增加。随着碱度的增加,高硅超细铁精矿球团矿渣相和硅酸盐相中的钙元素含量会逐渐增加,此外,碱度越高,赤铁矿晶粒越容易呈现多边形结构且晶粒间填充的渣相量越多。随着碱度增加,高硅超细铁精矿球团矿还原度和还原膨胀率先降低后增加,球团矿抗还原粉化性能减弱。碱度大于0.24后,球团矿内部孔隙率和铁酸钙相含量的增加使得还原气体能更容易扩散至球团矿内部并促进还原反应的进行,可以有效提高球团矿的还原度,碱度为1.20时的球团矿还原度比碱度为0.06时提高了34.9%。The high proportion of pellets in blast furnace smelting technology is an important solution to reduce carbon emissions and environmental pressures in the ironmaking system.Utilizing high-silicon ultrafine magnetite concentrate as raw material for pellet production helps expand domestic iron ore resources in China and increase the application of low-grade ores.The influence of basicity on the pelletization and reduction characteristics of highsilicon ultrafine magnetite concentrate pellets was systematically studied.Thermodynamic calculations,mineral phase analysis,scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS),and other methods were used to investigate their pelletization behavior and reduction characteristics.The research results show that with the increase of basicity,the compressive strength of high-silicon ultrafine magnetite concentrate pellets first increases and then decreases,while the porosity first decreases and then increases.Within the basicity range of 0.06 to 0.73,the compressive strength of the pellets exceeds 4000 N/pellet.The highest compressive strength and lowest porosity of the pellets are achieved at an basicity of 0.24.Increasing basicity reduces the content of silica dioxide phase in the high-silicon ultrafine magnetite concentrate pellets and promotes the formation of calcium iron phase and silicate phase.Under the conditions of basicity of 1.20 and temperature of 1300℃,the liquid phase proportion in the pellets can reach 24.38%.When the basicity is greater than 0.73,the amount of liquid phase in the pellets rapidly increases after 1250℃.With increasing basicity,the calcium content in the slag phase and silicate phase of the high-silicon ultrafine magnetite concentrate pellets gradually increases.Additionally,higher basicity leads to a more polygonal structure of hematite grains and more filling of slag phase between grains.With increasing basicity,the reduction degree and reduction swelling rate of the high-silicon ultrafine magnetite concentrate pellets first d

关 键 词：高硅超细铁精矿 熔剂性球团矿 碱度 抗压强度 固结行为 还原特性 

分 类 号：TF046.6[冶金工程—冶金物理化学]