含硼磁铁矿对超细粒级磁铁矿球团性能的影响  

Effect of boron-containing magnetite on properties of ultrafine-grained magnetite pellets

作　　者：温宝良 张晓萍 刘德楼[3] 李家新 吴宏亮 杨佳龙 WEN Bao-liang;ZHANG Xiao-ping;LIU De-lou;LI Jia-xin;WU Hong-liang;YANG Jia-long(School of Metallurgical Engineering,Anhui University of Technology,Ma'anshan 243032,Anhui,China;Ma'anshan Iron and Steel Co.,Ltd.,Ma'anshan 243003,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]马鞍山钢铁股份有限公司,安徽马鞍山243003 [3]抚顺新钢铁有限责任公司技术中心,辽宁抚顺113001

出　　处：《钢铁》2022年第11期33-41,共9页Iron and Steel

基　　金：国家自然科学基金资助项目(U1860113)。

摘　　要：超细粒级精矿球团化对中国贫矿资源应用有着特殊意义,但存在成球困难、生球质量差、成品球团强度低等问题,硼铁矿中硼和铁嵌布密切,应用难度大,然而其配加对提高球团性能有益。采用气体吸附法(BET法)测量比表面积并用扫描电镜(JSM6490)评价铁精矿粉和焙烧球团矿的微观结构,研究了添加含硼磁铁矿对超细精矿的成球性能、生球质量、预热焙烧强度的影响。结果表明,超细精矿中配加30%硼铁矿后,混合精矿成球性得到改善,达到中等成球性指标,生球落下强度从2.4次/(0.5 m)升高到4.0次/(0.5 m)、抗压强度从15.38 N/个增加到19.08 N/个、爆裂温度从340℃升高到410℃,优化配矿下可提高爆裂温度至460℃,球团的预热与焙烧时间缩短、温度降低,在预热时间与温度不变、焙烧时间相同、焙烧温度为1175℃条件下,球团强度(与100%超细精矿相比)提高900 N/个左右,达到了3500 N/个以上,在相同强度下,可降低焙烧温度近100℃。加入含硼磁铁矿可改善球团性能的原因为,含硼磁铁矿颗粒形貌复杂、碱性物质含量多、粒度粗,从而能有效帮助颗粒间嵌合,增加粉料分子水含量,改善成球性,提高生球强度与爆裂温度。MgO和B_(2)O_(3)会在球团内部生成低熔点液相,填充孔隙,促进焙烧温度降低,增强颗粒间网格状的均匀连结,提高焙烧球团的强度。The pelletization of ultra-fine iron ore has special significance for the application of lean ore resources in China. However, there are some problems such as difficulty in pelletizing, poor quality of green pellets, and low strength of finished pellets. Boron and iron in borax are closely disseminated and difficult to apply. However, its addition is beneficial to improving the performance of pellets. The specific surface area was measured by the BET method, and the microstructure of iron concentrate and roasted pellets was evaluated by scanning electron microscopy(JSM6490). The effect of adding boron-bearing magnetite on pelletizing performance, pellet quality, and preheating roasting strength of superfine magnetite was studied. The following results were obtained: after adding 30 % borax to the ultra-fine magnetite, the balling property of the mixed concentrate was improved to reach the medium balling index. The drop strength of the green ball increased from 2.4 times/0.5 m to 4.0 times/0.5 m, the compressive strength increased from 15.38 N/individual to 19.08 N/individual, and the burst temperature increased from 340 ℃ to 410 ℃. Under the optimized ore blending, the burst temperature could be increased to 460 ℃, the preheating and roasting time of the pellet was shortened, and the temperature was reduced. Under the conditions of the same preheating time and temperature, the same roasting time, and the roasting temperature of 1 175 ℃, the strength of the pellets(compared with 100% superfine concentrate) is increased by about 900 N/individual, reaching more than 3500 N/individual. Under the same strength, the roasting temperature can be reduced by nearly 100 ℃. The reason that adding boron-containing magnetite can improve the performance of pellets is that the morphology of boron-containing magnetite particles is complex, the content of alkaline substances is large, and the particle size is coarse, which can effectively help the intercalation between particles, increase the molecular water content of p

关 键 词：超细粒级磁铁矿 含硼磁铁矿 成球性能 生球质量 预热焙烧 

分 类 号：TF046.6[冶金工程—冶金物理化学]