高硅镁质熔剂性球团还原历程及冶金性能分析  

Reduction process and metallurgical properties analysis of high silicon magnesia flux pellets

作　　者：李卓 宗燕兵[1] 张建良[1] 刘征建[1] 王耀祖 马黎明 LI Zhuo;ZONG Yan-bing;ZHANG Jian-liang;LIU Zheng-jian;WANG Yao-zu;MA Li-ming(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Institute of Artificial Intelligence,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]北京科技大学人工智能研究院,北京100083

出　　处：《钢铁》2023年第3期34-42,52,共10页Iron and Steel

基　　金：国家自然科学基金资助项目(52174291);北京市科技新星资助项目(Z211100002121115)。

摘　　要：镁质熔剂性球团矿是适合中国高硅铁矿粉资源特征的铁矿粉造块工艺,可以改善高硅球团矿的冶金性能,但w(MgO)与高硅铁矿粉之间的耦合关系还有待进一步研究。以企业现场高硅铁矿粉为原料,氧化镁粉为熔剂制备高硅镁质熔剂性球团矿,研究不同矿粉配比及w(MgO)对球团矿冶金性能的影响,旨在得到合适的矿粉配比与w(MgO)。结果表明,随着矿粉配比(质量分数)(A矿粉∶B矿粉=30∶70/40∶60/50∶50)的变化,还原膨胀指数由6.8%降低到6.3%,低温还原粉化指数由98%降低到96%,还原度指数由77.1%降低到55.7%,熔滴温度区间由87℃增大到125℃,熔滴性能变差。当w(MgO)由1.00%升高到1.88%时,还原膨胀指数由7.4%降低到6.2%,低温还原粉化指数由98%降低到94%,还原度指数由65.1%升高到77.8%,软熔带位置逐渐下移。但当w(MgO)为1.46%时,熔滴温度区间最小。由还原历程分析得到,MgO的添加可以有效抑制硅酸盐的生成,提高渣相熔点,保证还原过程中球团矿的孔隙率。A矿粉中的赤铁矿不利于球团矿冶金性能的改善,且用高硅矿粉制备球团矿时,w(MgO)过高会产生大量高熔点液相,使软熔带变厚。所以,球团矿最优矿粉配比(A矿粉∶B矿粉)为30∶70,最优w(MgO)为1.46%。Magnesia flux pellet is an iron ore powder briquetting process suitable for the characteristics of high silica iron ore powder resources in China,which can improve the metallurgical properties of high silicon iron ore pellet,but the coupling relationship between w(MgO)and high silicon iron ore powder needs to be further studied.High silicon magnesia flux pellets were prepared by using iron ore powder as raw material and magnesia powder as flux.The effects of different ore powder ratio and w(MgO)on the metallurgical properties of pellets were studied in order to obtain appropriate powder ratios and w(MgO).The results show that with the change of ore powder ratio(A ore powder∶B ore powder are 30∶70/40∶60/50∶50),the reduction swelling index is reduced from 6.8%to 6.3%,the reduction degradation index is reduced from 98%to 96%,the reducibility index is reduced from 77.1%to 55.7%,and the cohesive zone increases from 87℃to 125℃,demonstrating a negative influence of A ore powder on the melt-down property of pellets.As w(MgO)increases from 1.00%to 1.88%,the reduction swelling index decreases from 7.4%to 6.2%,the reduction degradation index decreases from 98%to 94%,and the reducibility index increases from 65.1%to 77.8%,the position of the cohesive zone gradually moves down.But when w(MgO)is 1.46%,the cohesive zone is the narrowest.According to the analysis of reduction process,the addition of MgO can effectively inhibit the formation of silicate,improve the melting point of slag phase,and ensure the porosity of pellets in the reduction process.The hematite in A ore powder has A negative influence on the metallurgical proper-ties of the pellets.Moreover,high w(MgO)will produce A large number of high melting liquid phase,which thick-ens the soft melting zone.When high silicon ore powder is used to prepare the pellets.Therefore,the optimal ore powder ratio(A ore powder∶B ore powder)is 30∶70,and the optimal w(MgO)is 1.46%.

关 键 词：炼铁 高硅球团矿 MgO质量分数 还原历程 冶金性能 

分 类 号：TF046.6[冶金工程—冶金物理化学]