B_(2)O_(3)对氧化焙烧过程赤铁矿连晶程度的影响  

Effect of B_(2)O_(3)on degree of hematite crystallization during oxidation roasting

作　　者：赵天乐 张芳[1] 彭军[1] 王永斌[1] 常宏涛[1] 高伟民 ZHAO Tianle;ZHANG Fang;PENG Jun;WANG Yongbin;CHANG Hongtao;GAO Weimin(School of Material and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,Nei Mongol,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010

出　　处：《钢铁》2024年第1期22-33,共12页Iron and Steel

基　　金：国家自然科学基金资助项目(51864041);内蒙古自治区直属高校基本科研业务费资助项目(2023RCTD006)。

摘　　要：在焙烧过程中加入B_(2)O_(3)有利于得到低熔点化合物,提高球团强度和降低还原膨胀,使球团的冶金性能得到提高,但B_(2)O_(3)对赤铁矿的结晶和连晶程度的影响机理还缺少较为深入的研究。因此,为探明B_(2)O_(3)对赤铁矿连晶程度和赋存规律,通过在Fe_(3)O_(4)纯试剂中加入不同比例的B_(2)O_(3)纯试剂,经混合、压片和氧化焙烧后形成赤铁矿。模拟磁铁矿球团焙烧形成赤铁矿球团的过程,采用SEM-EDS、XRD、XPS等手段研究不同B_(2)O_(3)含量对焙烧压片中赤铁矿的连晶程度、晶体长大情况和微观结构的影响,结合拉曼光谱分析B_(2)O_(3)对赤铁矿晶体结构的影响,并对其微观结构、结晶度和晶粒尺寸进行了测定,最后针对不同B_(2)O_(3)含量对赤铁矿的连晶程度的影响进行了讨论和总结。研究结果表明,B_(2)O_(3)对氧化焙烧过程赤铁矿连晶程度有着先促进后抑制的作用,适量加入B_(2)O_(3)能够促进赤铁矿晶体长大和连晶程度的增长,当添加B_(2)O_(3)质量分数为6%、焙烧时间为40min时,赤铁矿的结晶程度最好,结晶度可达83.68%。XPS检测显示,随着B_(2)O_(3)含量的增加,赤铁矿中Fe^(3+)的比例逐渐升高,Fe^(3+)的比例最高可达92.53%。B_(2)O_(3)添加量进一步增加时,B_(2)O_(3)对渣相的流动性和渣相量的影响也进一步增加,渣相将赤铁矿晶粒浸润,抑制晶粒长大和晶粒间的连晶。通过拉曼光谱对赤铁矿晶体结构的检测结果显示,随着B_(2)O_(3)含量的增加,赤铁矿晶体的LO模式和Eu模式的峰强增加,这表明晶格缺陷引起的对称性破坏增加,晶体无序度更高,缺陷更高。Adding B_(2)O_(3)to the raw materials in the ball preparation process is beneficial for obtaining low melting point compounds,improving the ball strength,and reducing reduction swelling,thus enhancing the metallurgical performance.However,there is still a lack of in-depth research on the mechanism of how B_(2)O_(3)affects the crystallization and crystal continuity of hematite.Therefore,in order to understand the influence of B_(2)O_(3)on the crystal continuity and occurrence pattern of hematite,different proportions of B_(2)O_(3)pure reagents were added to Fe_(3)O_(4)pure reagents.The mixture was then pressed,oxidized,and transformed into hematite,simulating the process of hematite formation in the roasting of magnetite pellets.SEM-EDS,XRD,XPS,and other methods were used to study the influence of different B_(2)O_(3)contents on the crystal continuity,crystal growth,and microstructure of hematite in the roasting pellets.Raman spectroscopy was used to analyze the effect of B_(2)O_(3)on the crystal structure of hematite.Furthermore,the microstructure,crystallinity,and grain size were determined.Finally,the impact of different B_(2)O_(3)contents on the crystal continuity of hematite was discussed and summarized.The research results show that B_(2)O_(3)has a promoting effect on the crystal continuity of hematite during the oxidation roasting process,followed by inhibitory effects.The proper addition of B_(2)O_(3)can promote crystal growth and enhance the crystal continuity of hematite.When the mass percent of B_(2)O_(3)is 6%and the roasting time is 40minutes,the crystallinity of hematite is the best,reaching 83.68%.XPS analysis demonstrates that as the B_(2)O_(3)content increases,the proportion of Fe^(3+)in hematite gradually increases,with Fe^(3+)accounting for up to 92.53%.As the B_(2)O_(3)content further increases,the influence of B_(2)O_(3)on slag fluidity and slag phase content increases.The slag phase infiltrates the hematite grains,inhibiting grain growth and crystal continuity.Raman spectroscopy analysis of th

关 键 词：B_(2)O_(3) 氧化焙烧 赤铁矿 连晶程度 晶格常数 

分 类 号：TF046.2[冶金工程—冶金物理化学]