叶蛇纹石同步辐射X射线粉末衍射脱水动力学研究 |
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作者姓名: | 刘涛 申珂玮 刘川江 王多君 |
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作者单位: | 中国科学院大学地球与行星科学学院, 北京 100049 |
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基金项目: | 国家自然科学基金(41874104,91958216)资助 |
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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~5 μm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。
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关 键 词: | 叶蛇纹石 脱水动力学 X射线粉末衍射 |
收稿时间: | 2019-04-16 |
修稿时间: | 2019-06-19 |
Kinetic study of antigorite dehydration using synchrotron X-ray powder diffraction |
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Authors: | LIU Tao SHEN Kewei LIU Chuanjiang WANG Duojun |
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Institution: | College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China |
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Abstract: | Synchrotron X-ray powder diffraction method was used to study dehydration kinetics of antigorite with particle size of ~5 μm. 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. |
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Keywords: | antigorite dehydration kinetics X-ray powder diffraction |
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