低温合成镁铝尖晶石的研究

Synthesis of Mg-Al spinel at low temperature

采用铝厂污泥和碱式碳酸镁为主原料合成镁铝尖晶石,探讨了低温阶段（从800-1500℃）镁铝尖晶石的形成过程,采用XRD和SEM表征不同温度样品的晶相及微观形貌.结果表明：800℃时即可观察到镁铝尖晶石的特征峰,但谱峰不完整,强度不高,且明显宽化,表明晶体尚处于成核期,含量较少;至1400℃镁铝尖晶石谱峰已完整尖锐,继续升高温度,衍射峰强度增加,表明晶相含量增加.SEM观察结果与XRD分析一致,1500℃镁铝尖晶石晶粒发育完整清晰,外形呈典型的八面体形貌,晶粒排列致密.

Mg-Al spinel was synthesized by using waste aluminum slag and （MgCO3 ）4Mg（OH）25H2O as main starting materials. The forming course at low temperature （ from 800 to 1 500 ℃ ） was characterized via XRD and SEM techniques. The results show that the characteristic peaks of Mg-Al spinel can be detected at the temperature of 800℃, but the strength is low and be obviously broadened. It suggests that the grains of Mg-Al spinel begin to form and its content is low at this temperature. The diffraction peak strength of Mg-Al spinel increases with increasing temperature which shows that its content is increasing. SEM observation results are in according with XRD analysis. At the temperature of 1 500℃, Mg-Al spinel crystals grow maturely, arrange compactly and take on typical octahedral look.