晶核剂对白云鄂博东尾矿微晶玻璃析晶及性能的影响

Effect of Nucleating Agent on Crystallization Characteristics and Properties of Baiyunebo East Mine Tailing Glass-ceramics

以白云鄂博东尾矿及粉煤灰为主要原料,采用熔融法制备得到了CaO-MgO-Al2O3-SiO2(CMAS)系特种微晶玻璃。制备流程包括熔融、退火、核化及晶化过程。基于X射线衍射和拉曼光谱研究了微晶玻璃的晶相结构及分子振动模式、借助于扫描电子显微镜及原子力显微镜对微晶玻璃的耐磨及断裂特性进行了表征;利用差热分析研究了共生晶核剂对微晶玻璃核化及晶化过程的作用机理。结论表明:随着尾矿含量的逐渐降低,微晶玻璃的析晶特性及性能先增强后减弱。微晶玻璃的耐磨性主要由晶相决定,其断裂特性属于沿晶断裂,热膨胀系数的变化规律与析晶特性相一致。

Glass-ceramics in the CaO-MgO-Al2O3-SiO2（ CMAS） quaternary system were produced by the melting method,using Baiyunebo east mine tailing and fly ash as main sources of raw materials. The processes of making glass-ceramics include glass melting,annealing,nucleation and crystallization stage,etc. The crystal structure and molecular vibrational modes of glass-ceramics were confirmed by X-ray diffraction（ XRD） and Raman spectra. The wear and fracture characteristics of glass-ceramics were researched by scanning electron microscope（ SEM） and atomic force microscope（ AFM）. The influences of intergrowth of nucleating agent on nucleation and crystallization process of glass-ceramics were systematically researched by a differential thermal analysis（ DTA） measurement. The results indicate that with the decrease of tailing,the crystallization characteristics and properties of glass-ceramics first increase and then decrease. The wear resistance of glass-ceramics is mainly determined by the crystalline phase and the fracture properties belong to intergranular fracture. The variations of coefficient of thermalexpansion characteristics are consistent with the crystallization characteristics of glass-ceramics.