叶蛇纹石同步辐射X射线粉末衍射脱水动力学研究  

Kinetic study of antigorite dehydration using synchrotron X-ray powder diffraction

作　　者：刘涛 申珂玮 刘川江 王多君 LIU Tao;SHEN Kewei;LIU Chuanjiang;WANG Duojun(College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院大学地球与行星科学学院,北京100049

出　　处：《中国科学院大学学报（中英文）》2020年第6期793-797,共5页Journal of University of Chinese Academy of Sciences

基　　金：国家自然科学基金(41874104,91958216)资助。

摘　　要：采用同步辐射X射线粉末衍射方法在等温条件下研究粒径为~5μm的叶蛇纹石脱水动力学,在680、700、710和720℃下观测叶蛇纹石脱水前后特征峰随时间变化的特征。结果发现,随加热时间的增加,叶蛇纹石的特征峰缓慢消失,伴有镁橄榄石特征峰出现,但无顽火辉石相出现。通过Avrami方程,获得叶蛇纹石脱水反应级数(n)为1.1~1.3,表明叶蛇纹石脱水过程受晶界成核控制。利用Arrhenius方程,获得叶蛇纹石脱水仅出现镁橄榄石相所需活化能为105.97 kJ/mol,指前因子为333.62 s^-1。Synchrotron X-ray powder diffraction method was used to study dehydration kinetics of antigorite with particle size of^5μm.The isothermal heating method was used to observe antigorite dehydration at 680,700,710,and 720℃,respectively.It was found that,with the increase of heating time,the characteristic peak of antigorite slowly disappeared and the characteristic peak of forsterite formed,but no enstatite appeared.The reaction order n is 1.1~1.3 by the Avrami equation,indicating that antigorite dehydration is controlled by grain boundary nucleation.Activation energy for the formation of forsterite from antigorite is 105.97 kJ/mol,and the pre-exponential factor is 333.62 s^-1 in the Arrhenius equation.

关 键 词：叶蛇纹石 脱水动力学 X射线粉末衍射 

分 类 号：O722.4[理学—晶体学]