毒重石对含钛无氟保护渣熔渣结构和析晶行为的影响  

Effect of witherite on slag structure and crystallization behavior of titanium-containing fluorine-free mold fluxes

作　　者：刘子瑶 刘磊 韩秀丽 张玓 孙昌奇 郭静静 LIU Ziyao;LIU Lei;HAN Xiuli;ZHANG Di;SUN Changqi;GUO Jingjing(College of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,Hebei,China;College of Mining Engineering,North China University of Science and Technology,Tangshan 063210,Hebei,China;Hebei Iron and Steel Laboratory,Tangshan 063210,Hebei,China;Hebei Collaborative Innovation Center for Green Development and Ecological Restoration of Mineral Resources,Tangshan 063210,Hebei,China)

机构地区：[1]华北理工大学冶金与能源学院,河北唐山063210 [2]华北理工大学矿业工程学院,河北唐山063210 [3]河北省钢铁实验室,河北唐山063210 [4]河北省矿产资源绿色开发与生态修复协同创新中心,河北唐山063210

出　　处：《钢铁》2024年第11期102-111,共10页Iron and Steel

基　　金：国家自然科学基金资助项目(51774140);河北省自然科学基金资助项目(E2024209062);河北省省属高校基本科研业务费资助项目(JQN2022008);唐山市科技计划资助项目(24130206C)。

摘　　要：在连铸无氟保护渣的应用探索中,含钛无氟保护渣以其独有的析晶矿相优势和改善保护渣物化性能的效果,成为无氟保护渣领域的研究热点。但由于高熔点矿物的存在,导致保护渣熔点和黏度较高,而毒重石中的钡可以改善含钛保护渣的理化性能,使得含钛保护渣具有较好的应用效果。选用含钛高炉渣、石灰石、石英砂、硼砂、纯碱和毒重石(BaCO3)作为主要原料制备含钛无氟保护渣,对无氟保护渣熔渣结构和析晶行为进行了系统研究,以查明毒重石作为氟替代物在含钛无氟保护渣中的作用机制,从而实现含钛无氟保护渣的工业化应用。结果表明,随着毒重石质量分数从1%增加到5%,熔渣中Ca—O键和Ba—O键稳定性、硅氧四面体内部与外部有序度以及硅酸盐结构聚合度均表现为先降低后升高,而Si—O平均配位数和氧硅比呈现为先升高后降低的趋势;含钛保护渣主要析出相为钙钛矿、霞石和硼硅酸钙,开始析晶温度和钙钛矿比例变化较小,岛状结构的硼硅酸钙含量先升高后降低,架状结构的霞石含量先降低后升高,当毒重石质量分数为3%时硼硅酸钙比例达到峰值为14.5%,霞石比例为17.9%。保护渣熔渣结构的改变会影响保护渣的析晶行为,保护渣熔渣硅氧网络结构的复杂度升高,则会促进复杂结构的硅酸盐矿物含量升高。The exploration of the application of fluorine-free mold flux in continuous casting has seen titanium-containing fluorine-free mold flux become a research hotspot in the field of fluorine-free mold flux.This is due to its unique advantages in terms of crystallization mineral phase and the improvement of physical and chemical properties of mold flux.This type of mold flux has attracted much attention because of its excellent performance and effectiveness.However,due to the existence of high melting point minerals,the melting point and viscosity of mold flux are high.The barium in the witherite can improve the physical and chemical properties of the titanium-containing mold flux,so that the titanium-containing mold flux has a good application effect.Titanium-containing fluorine-free mold flux was prepared by using titanium-containing blast furnace slag,limestone,quartz sand,borax,soda ash and witherite(BaCO3)as the main raw materials.The structure and crystallization behavior of fluorine-free mold flux slag were systematically studied to find out the mechanism of witherite as a fluorine substitute in titanium-containing fluorine-free mold flux,so as to realize the industrial application of titanium-containing fluorine-free mold flux.The results indicate that as the mass percent of witherite increases from 1%to 5%,the stability of Ca—O bond and Ba—O bond in the slag,the internal and external order degree of silicon-oxygen tetrahedron and the polymerization degree of silicate structure decrease first and then increase,while the average coordination number of Si—O and the ratio of oxygen to silicon increase first and then decrease.The main precipitated phases of titanium-containing mold flux are perovskite,nepheline and calcium borosilicate.The initial crystallization temperature and the proportion of perovskite change little.The content of calcium borosilicate with island structure initially increases and then decreases,while the content of nepheline with frame structure initially decreases and then increases.W

关 键 词：含钛无氟保护渣 熔渣结构 析晶行为 毒重石 析晶温度 析出矿物 

分 类 号：TF777[冶金工程—钢铁冶金]