熔盐法合成白榴石机理与晶粒生长动力学  

Mechanism and growth kinetics of leucite particles synthesized by molten salt method

作　　者：罗伟华[1] 周振君[1] 栾丽君[1] 赖政清[1] 刘超[1] 

机构地区：[1]长安大学材料科学与工程学院,陕西西安710064

出　　处：《无机盐工业》2015年第12期35-37,42,共4页Inorganic Chemicals Industry

摘　　要：采用硫酸铝钾-硫酸钾熔盐法制备了白榴石粉体。利用扫描电镜(SEM)和X射线衍射仪(XRD)对白榴石粉体的形貌、粒度和物相进行了观察与分析。利用经典动力学方程研究了白榴石粉体在熔盐中的合成机理及晶粒生长动力学。结果表明:熔盐法合成白榴石粉体的生长过程可以划分为低温和高温两个阶段,不同阶段遵循不同的生长机理。在低于1 050℃的低温阶段白榴石晶粒的生长速率较小,生长过程受扩散过程控制;在高于1 050℃的高温阶段白榴石晶粒的生长速率显著增加,生长过程受界面反应控制。两个阶段对应的表观生长活化能分别为39.33 k J/mol和65.78 k J/mol。Leucite powders were synthesized by K3Al（SO4）3-K2SO4 molten salt method.The morphology,particle size,and phase composition of the leucite powders were analyzed by SEM and XRD.The mechanism and growth kinetics of preparing leucite powders in molten salt were studied by typical dynamics equation.Results indicated that the particle growth process could be divided into two stages（low temperature and high temperature stages）,in which different growth mechanisms were obeyed.The particle growth rate was relatively low at temperature lower than 1 050 ℃,and the growth process was dependent upon atom diffusion.When the temperature was higher than 1 050 ℃,the growth rate increased obviously,and the growth process was controlled by the interface reaction.The apparent activation energies of the two stages were 39.33 k J/mol and 65.78 k J/mol,respectively.

关 键 词：白榴石 熔盐法 生长机理 生长动力学 

分 类 号：TQ127.2[化学工程—无机化工]