熔剂颗粒在烧结过程中的特征演变及影响  

Characteristic evolution and corresponding influence of flux particles in sintering process

作　　者：史先菊 王强[1] 李光强[1] 刘代飞[3] 李军[2] SHI Xian-ju;WANG Qiang;LI Guang-qiang;LIU Dai-fei;LI Jun(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;Baosteel Central Research Institute(Rsearch and Development Center of Wuhan Iron and Steel Co.,Ltd.),Wuhan 430080,Hubei,China;School of Energy and Power Engineering,Changsha University of Science and Technology,Changsha 410114,Hunan,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081 [2]宝钢股份中央研究院(武钢有限技术中心),湖北武汉430080 [3]长沙理工大学能源与动力工程学院,湖南长沙410114

出　　处：《钢铁》2021年第12期28-35,共8页Iron and Steel

基　　金：国家自然科学基金面上资助项目(51674042)。

摘　　要：对烧结现场生产进行全流程取样,分析熔剂颗粒在烧结过程中的演变规律,及其对烧结过程的影响。结果表明,在烧结混合料制粒过程中,小于0.5 mm熔剂颗粒较铁矿粉颗粒更容易黏附至核颗粒表面形成新的颗粒,从而相对均匀地分布至混合料各粒级中。大于0.5 mm粒级熔剂颗粒作为核黏附一定厚度的黏附层形成新的颗粒,黏附层厚度均小于1 mm,因此,新颗粒直径仅在原始颗粒粒径基础上增大不超过2 mm。同时由于熔剂原始颗粒粒级较细,导致制粒后大于5 mm粒级混合料中熔剂含量较少。而在烧结台车布料过程中粒级存在偏析,大颗粒向下分布,最底层大于5 mm粒级颗粒分布最多,从而导致熔剂的偏析,混合料中大于5 mm粒级颗粒增多加大了熔剂的偏析,混合料中3~5 mm粒级颗粒增多减弱了熔剂的偏析。料层粒级偏析使烧结料层,最底层混合料中熔剂总量变少,大颗粒熔剂增多,熔剂颗粒数量减少,导致熔剂分布点变少,熔剂分布不均匀程度增加,局部高碱度环境变少,液相产生的难度增加。同时,由于颗粒的偏析,最底层混合料中大颗粒铁矿粉增加,出现更多的未熔原矿,最终导致烧结料层最底层烧结矿质量变差。In order to study the characteristic evolution of flux particles and corresponding influence on the properties of sinter,the sampling analysis of the whole actual sintering process was carried out.The results indicated that the flux particles less than 0.5 mm were easier to adhere to the surface of core particles than iron ore particles in the mixing process,and these particles distribute uniformly within each grade of the mixture,While the flux particles larger than 0.5 mm,served as the core particles,were adhered with a certain thickness of the adhesive layer that forming new particles,and moreover the thickness of the attachment layer was less than 1 mm,there for,the diameter of the new particles only increases by no more than 2 mm on the basis of the original particles.At the same time,the original flux particles were fine,led to less flux content in the mixture larger than 5 mm after granulation.In the sintering feeding process,there was segregation of particle size,large particles were segregated downward,and the particles larger than 5 mm at the bottom layer were distributed most,resulting in segregation of flux.The increase of particles larger than 5 mm in the mixture increases the flux segregation,while the increase of 3-5 mm particles reduces the flux segregation.Therefore,segregation of particle size reduces the total flux at the bottom layer,increases the larger particle flux.The decrease of the amount of flux particles reduces the distribution point of the flux,and thus increases the uneven distribution of the flux and deteriorates the local high alkalinity environment,then increases the difficulty for liquid phase generation.At the same time,due to the segregation of particles,the large particle iron ore powder in the bottom mixture increases and more unmelted raw ore appears,which eventually leads to the poor quality of the bottom sinter.

关 键 词：铁矿烧结 熔剂 偏析分布 物相组成 显微结构 

分 类 号：TF046.4[冶金工程—冶金物理化学]