熔制保温时间对CAMS系矿渣微晶玻璃结构与性能的影响

Influence of Melt Holding Time on the Microstructure and Properties of CAMS Slag Glass-ceramics

以白云鄂博二次选后尾矿、高炉渣和粉煤灰为主要原料,采用熔融法制得CaO-Al_2O_3-MgO-SiO_2(CAMS)系微晶玻璃,利用DSC、XRD、SEM、EDS、Raman、红外光谱及理化性能测试手段,研究了熔制过程中不同保温时间对微晶玻璃结构与性能的影响。结果表明:随着熔制保温时间的延长,矿渣玻璃熔液中氟的挥发及对氧化铝坩埚的侵蚀导致基础玻璃中氟含量降低而Al2O3含量升高,基础玻璃析晶温度呈先上升后下降的趋势,微晶玻璃主晶相为透辉石,晶粒出现先细化后粗化的趋势,第二相萤石相随着保温时间的延长逐渐消失,最终导致微晶玻璃结构及理化性能发生改变。当玻璃熔制保温时间为5h时,制备的微晶玻璃综合性能最优,其密度、抗折强度、显微硬度及耐酸碱性分别为3.09g/cm3、201 MPa、7 021 MPa、97.78%和98.83%。

Quaternary CaO-Al2O3-MgO-SiO2（CAMS）glass ceramics were synthesized mainly with Bayan Obo mine secondary tailing,blast furnace slag,and fly ash by melting method.The microstructure and properties of the glass ceramics under different glass melt holding time was systematically investigated by DSC,XRD,SEM,EDS,Raman,infrared spectral and physicochemical properties tester.The results indicated that the content of CaF2 increased and the amount of Al2O3 decreased as the increasing holding time.Due to the change of the composition of samples,the dominant crystalline phase was diopside and the crystallization temperature of the basic glass first increased and then decreased.Meanwhile the second phase（identified as fluorite）would disappear gradually and the grain of the glass-ceramics first refined and then coarsened with the increase of glass melt holding time.Based on above-mentioned reasons,the structure and performance of the glass ceramics had changed.The glass-ceramics with glass melt holding time of 5 hshowed the optimal properties,of which the density,three-point bending strength and the resistance to acid or alkali corrosion are 3.09 g/cm3,201 MPa,7 021 MPa,97.78% and 98.83%,respectively.