Study on the mechanisms and kinetics of complex's thermal decomposition getting anhydrous magnesium chloride
Study on the mechanisms and kinetics of complex's thermal decomposition getting anhydrous magnesium chloride
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DOI：
10.1016/j.jaap.2007.05.004
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发表时间：
2008
影响因子：
6
通讯作者：
Yu-long Wu;Xiao‐Fang Huang;Ming-de Yang;Shuping Zou;J. Dang;Hu-sheng Hu-Hu-sheng-Hu-10762150
中科院分区：
文献类型：
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作者：
Yu-long Wu;Xiao‐Fang Huang;Ming-de Yang;Shuping Zou;J. Dang;Hu-sheng Hu-Hu-sheng-Hu-10762150
本文研究了用复热分解法制备无水氯化镁（MgCl2·6H2O）。在此过程中，利用热重-差热分析（TG-DTA）和热重-质谱联用（TG-MS）研究了制备无水MgCl2的中间体MgCl2·C6H5NH2·HCl·6H2O配合物的热性质。结果表明，配合物的热分解过程可分为四个阶段，其中前两个阶段为配合物中结晶水的蒸发，后两个阶段为配合物中盐酸苯胺（C6H5NH2·HCl）的消除。热分解各阶段失重量与已有理论吻合较好。采用Coats-Redfern法和Malek法对热分解过程进行动力学分析。结果表明，前三个阶段服从二维相界机制（R2模型），最后一个阶段服从三维扩散动力学（D3）。4个阶段的表观活性能分别为127.4、124.8、142.3和329.0kJmol−1。频率因子分别为1.28×1018、7.94×1015、5.98×1016and 4.39×1034s−1。该研究为MgCl2·C6H5NH2·HCl·6H2O分解工艺的工业化提供了有价值的理论依据。
This paper investigated the preparation of anhydrous magnesium chloride (MgCl2) from bischofite (MgCl2·6H2O) by complex thermal decomposition method. In this process, the thermal properties of complex compound MgCl2·C6H5NH2·HCl·6H2O, an intermediate to produce anhydrous MgCl2, was studied using thermogravimetry–differential thermal analysis (TG–DTA) and simultaneous thermogravimetry–mass spectrometry (TG–MS). The results showed that the thermal decomposition process of the complex combination can be divided into four stages, of which the first two stages belong to the evaporation of crystal water in the complex while the last two ones attribute to the elimination of aniline hydrochloride (C6H5NH2·HCl) from the complex. The weight loss for each stage of thermal decomposition was in good agreement with the existing theory. The kinetic analysis of the thermal decomposition process was performed using Coats–Redfern method and Malek method. Results suggested that the first three stages submit to 2-dimentional phase boundary mechanism (model R2) while the last stage rule follows 3-dimensional diffusion (D3) kinetics. The apparent active energies of four stages are 127.4, 124.8, 142.3 and 329.0kJmol−1, respectively. The frequency factors are 1.28×1018, 7.94×1015, 5.98×1016and 4.39×1034s−1, respectively. This study provides a valuable theoretical basis for industrializing the MgCl2·C6H5NH2·HCl·6H2O decomposition process.