磁铁精矿性质对铁矿粉烧结特性的影响机理分析  

Mechanism analysis of effect of magnetite concentrate properties on sintering characteristics of iron ore fines

作　　者：朱德庆[1,2,3] 宋刘刚 杨聪聪[1,2,3] 潘建 郭正启[1,2,3] 李思唯[1,2,3] ZHU Deqing;SONG Liugang;YANG Congcong;PAN Jian;GUO Zhengqi;LI Siwei(School of Mineral Processing and Bioengineering,Central South University,Changsha 410083,Hunan,China;Low Carbon and Hydrogen Metallurgy Research Center,Central South University,Changsha 410083,Hunan,China;Engineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and Utilization,Central South University,Changsha 410083,Hunan,China)

机构地区：[1]中南大学资源加工与生物工程学院,湖南长沙410083 [2]中南大学低碳与氢冶金研究中心,湖南长沙410083 [3]中南大学金属资源开发利用碳减排教育部工程研究中心,湖南长沙410083

出　　处：《钢铁》2024年第10期20-31,共12页Iron and Steel

基　　金：国家自然科学基金资助项目(52004339);中国宝武低碳冶金创新基金资助项目(BWLCF202216)。

摘　　要：磁铁精矿是常用的烧结原料之一,而不同产地的磁铁精矿通常具有不同性质,将其配入烧结混合矿中必然会对烧结过程及烧结矿的质量产生影响。通过烧结杯试验,对比了粒度较细的高镁国产磁铁精矿(DM)和粒度较粗的高硅澳洲某磁铁精矿(AM)对赤铁矿-针铁矿-磁铁矿型混合料的烧结性能及其烧结矿冶金性能的影响,着重从原料性质和烧结矿微观矿相结构角度分析了磁铁精矿性质对铁酸钙生成特性及对烧结矿低温还原粉化性能的影响。结果表明,随着AM矿替代DM矿的比例从0提高到30%,烧结矿转鼓指数从59.87%降低至57.35%,成品率从63.69%降低至60.92%,利用系数从1.49 t/(m^(2)·h)降低至1.30 t/(m^(2)·h),固体燃耗从76.62 kg/t升高至78.86 kg/t,还原度指数IR从86.64%降低至83.08%,低温还原粉化指数I_(RD>3.15mm)从68.69%降低至49.40%。从烧结矿矿相上看,随着AM矿替代DM矿比例的提高,烧结矿中复合铁酸钙含量明显减少,结晶和发育情况变差,从针状向短柱状或板状转变,同时硅酸盐玻璃相和不规则骸晶状赤铁矿含量增加。这是因为粒度较细的DM矿较粒度较粗的高硅AM矿具有更高的自熔性和更优的氧化性,从而有利于生成初生液相,促进核颗粒同化,形成黏结强度高的黏结相。Magnetite concentrate is one of the commonly used sintering materials.Magnetite concentrates from different origins usually have different properties,and their addition to sintered mixed ores will inevitably have an impact on the sintering process and the quality of sintered ore.Through sinter pot tests,the sintering performance of hematite-goethite-magnetite type mixed ores and the metallurgical properties of sintered products were compared between finer-grained domestic high magnesium magnetite concentrate(DM)and coarser-grained high silicon Australian magnetite concentrate(AM).Moreover,the effect of magnetite concentrate properties on the generation characteristics of calcium ferrite and the low-temperature reduction degradation performance of sinter products was analyzed from the perspectives of raw material properties and microstructure of sinter products.The results indicated that,as the proportion of AM replacing DM increased from 0 to 30%,tumble index of sinter products decreased from 59.87%to 57.35%,yield decreased from 63.69%to 60.92%,productivity decreased from 1.49 t/(m^(2)·h)to 1.30 t/(m^(2)·h),solid fuel consumption increased from 76.62 kg/t to 78.86 kg/t,reduction index IR decreased from 86.64%to 83.08%,and the low-temperature reduction degradation index I_(RD>3.15mm)decreased from 68.69%to 49.40%.From the perspective of mineralogy of sinter products,as the proportion of AM replacing DM increased,the content of composite calcium ferrite in sinter products significantly decreased,and the crystallization and development situation deteriorated,transitioning from needle shaped to short columnar or plate-like.Meanwhile,the amount of silicate glass phase and irregular skeletal hematite increased.The reason for this was that DM with finer particle size has higher self-fluxing and better oxidation properties than high silicon AM with coarser particle size,which was conducive to the formation of primary melting phase,promoting the assimilation of nuclear particles,and forming a bonding phase with high bon

关 键 词：磁铁精矿 氧化性能 混合矿 烧结 低温还原粉化 

分 类 号：TF046.4[冶金工程—冶金物理化学]