CeO_(2)对形成镁铝尖晶石转变温度的影响

Eff ect of CeO_(2) Addition on Phase Transformation Temperature of Magnesia-alumina Spinel

采用固相烧结法合成镁铝尖晶石粉末,通过X射线衍射分析尖晶石的相变转变温度。结果表明:CeO_(2)对相变反应具有促进作用,添加3%CeO_(2)能够使尖晶石的相变转变温度由1500℃降低到1300℃;随着温度的升高,尖晶石生成量增加。加入稀土CeO_(2)含量大于1%时,随着CeO_(2)含量的增加,稀土CeO_(2)对尖晶石的相变温度的促进作用增强;CeO_(2)含量小于3%时,保温时间对尖晶石的形成影响不大,在1500℃下,当CeO_(2)含量为5%时,随着保温时间的延长,尖晶石的含量增加。对温度、保温时间和稀土加入量综合考虑,生产中添加3%CeO_(2),1300℃煅烧保温2h为宜。

Magnesium-aluminum spinel was synthesized by solid-phase sintering method. The phase transformation temperature of spinel was studied by XRD. The results indicate that CeO_(2)can promote the transformation of spinel. Adding 3% CeO_(2)can reduce the transition temperature of spinel from 1500℃ to 1300℃. With the increase of temperature, spinel production increases. When CeO_(2)content is more than 1%, with the increase of CeO_(2)content, the ef fect of rare earth CeO_(2)on the transformation temperature of spinel is enhanced. When CeO_(2)content is less than 3%, the holding time has little ef fect on the formation of spinel. At 1500℃, when CeO_(2)content is 5%, the content of spinel increases with the extension of holding time. Considering the temperature, holding time and the amount of rare earth, adding 3% CeO_(2)and calcination at 1300℃ for 2h is appropriate.