铁铌联合作用机制对CMAS系微晶玻璃析晶机制的影响  

Crystallization Mechanism of CMAS Glass-Ceramics with Interaction Mecha⁃nism between Iron and Niobium

作　　者：张宇轩 李宇 张铁柱 李航任 欧阳顺利 吴楠楠 Zhang Yuxuan;Li Yu;Zhang Tiezhu;Li Hangren;Ouyang Shunli;Wu Nannan(School of Material and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China;Liberal Arts College,Guangzhou Maritime University,Guangzhou 510725,China;Department of Chemical Engineering,Ordos Institute of Technology,Erdos 017000,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 [2]广州航海学院文理学院,广东广州510725 [3]鄂尔多斯应用技术学院化学工程系,内蒙古鄂尔多斯017000

出　　处：《稀有金属》2024年第8期1154-1162,共9页Chinese Journal of Rare Metals

基　　金：国家自然科学基金地区基金项目(11964025,11564031);内蒙古自治区重大基础研究开放课题(0406091701)资助。

摘　　要：白云鄂博尾矿的大量堆积造成了矿产资源的严重浪费,使含铌的高价值白云鄂博尾矿得不到有效利用,而制备以铁铌为晶核剂的CaO-MgO-Al_(2)O_(3)-SiO_(2)(CMAS)系矿渣微晶玻璃是高值利用含铌白云鄂博尾矿的方法之一。利用差示扫描量热法(DSC)、X射线衍射(XRD)和拉曼光谱研究了铁铌的不同掺杂量对样品热行为和结构的影响。结果表明:氧化铁作为晶核剂时微晶玻璃材料中析出的晶相主要是透辉石相,而铌作为晶核剂添加时会促使烧绿石、CaNb_(2)O_(6)富铌晶相的析出,通过改变铁铌的比例能够使堇青石、倍长石和氟金云母相的析出。氧化铌的添加使析晶温度升高从而抑制样品的析晶,但是同时添加铁铌时会使氧化铌抑制析晶的作用减弱。氧化铌添加到样品中之后以[NbO_(6)]结构基元的形式将玻璃网络中非桥氧键连接,从而提高硅氧网络的聚合度,而氧化铁能够将铌形成的桥氧键破坏。另外,铌的4d5s轨道和铁的3d4s轨道能够同时提供电子,提高费米能级附近的态密度增加原子的活性,有助于促进晶体的形成。铁铌联合作用机制的研究为高值化利用白云鄂博尾矿和设计独特性能的微晶玻璃提供理论依据。With the exploitation and utilization of Bayan Obo mine,a large number of tailings were produced which had not been used effectively.The waste of calcium oxide,silicon oxide,alumina,magnesium oxide and other resources caused by the accumulation and landfill tailings is more urgent to solve the high value utilization of rare metal elements such as rare earth,niobium,titanium and so on.The preparation of CaO-MgO-Al_(2)O_(3)-SiO_(2)(CMAS)glass-ceramics with ferric oxide and niobium oxide as nucleating agents was one of the effective means for high value utilization of Bayan Obo tailings.The results showed that the crystal phase composition of glass-ceramics samples can be controlled by changing the doping ratio of ferric oxide and niobium oxide by changing the doping ratio of ferric oxide and niobium oxide.Ferric oxide could reduce the crystallization temperature of glass-ceramics and promoted crystallization,and diopside phase was the main crystal phase.However,niobium oxide as nucleating agent could promote the niobium-rich crystal phase precipitation of pyrochlore and CaNb_(2)O_(6),but increase the crystallization temperature inhibiting the crystallization of diopside phase in glass-ceramics.The solution ratio of calcium to niobium in Ca_(2)Nb_(2)O_(7)and CaNb_(2)O_(6)was 1∶1 and 1∶2,respectively.Therefore,when the amount of niobium was too much,CaNb_(2)O_(6)precipitated,because it could make more niobium from the glass phase with higher internal energy to the crystal phase with lower internal energy.It could be found that the glass-ceramics of the target crystal phase composition could be obtained by changing the proportion of Fe-Nb addition.When the niobium content was constant,the crystallization temperature of the sample decreased obviously with the increase of the iron content,which indicated that iron played a role in promoting the crystallization of glass-ceramics.When the amount of iron was constant,the crystallization temperature increased with the increase of the amount of niobium,which meant that t

关 键 词：微晶玻璃 铁铌联合作用机制 拉曼光谱 玻璃网络 

分 类 号：TQ171[化学工程—玻璃工业]