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Journal of Inorganic Materials

Journal of Inorganic Materials >

2010 , Vol. 25 >Issue 3: 306 - 310

DOI: https://doi.org/10.3724/SP.J.1077.2010.00306

Research Paper

Thermal Decomposition Mechanism of MgCl 2·6H2O

  • HUANG Qiong-Zhu ,
  • LU Gui-Min ,
  • WANG Jin ,
  • YU Jian-Guo
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  • StateKey Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China

Received date: 2009-07-10

  Revised date: 2009-08-30

  Online published: 2010-03-20

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Abstract

The thermal decomposition mechanism and the intermediate morphology of MgCl2·6H2O before and after calcination by a resistance furnace, were studied using integrated thermal analysis, X-ray diffraction, scanning electron microscope, energy dispersive X-ray spectrum and chemical analysis. The results showed that there were six steps in the thermal decomposition of MgCl2·6H2O, producing MgCl2·4H2O at 69℃, MgCl2·2H2O at 129℃, MgCl2·nH2O(1≤n≤2) and MgOHCl at 167℃, and the MgCl2·nH2O(1≤n≤2) converted to Mg(OH)Cl·0.3H2O with dehydration and hydrolysis simultaneously at 203℃, Mg(OH)Cl·0.3H2O dehydrated to MgOHCl at 235℃, MgOHCl directly converted to MgO at 415℃. The MgOHCl particle was irregular with porous structure, while Mg(OH)Cl·0.3H2O particle had relatively flat surface.

Key words： MgCl2·6H2O; Mg(OH)Cl·0.3H2O; dehydration; hydrolysis; thermal decomposition

Cite this article

HUANG Qiong-Zhu , LU Gui-Min , WANG Jin , YU Jian-Guo . Thermal Decomposition Mechanism of MgCl 2·6H2O[J]. Journal of Inorganic Materials, 2010 , 25(3) : 306 -310 . DOI: 10.3724/SP.J.1077.2010.00306

References

［1］陈雪刚, 吕双双, 夏枚生, 等. 碱式氯化镁晶须的制备与应用进展. 材料导报, 2009, 23(4): 52-55.

［2］KashaniNejad S, Ng K W, Harris R. Chlorination of MgOHCl with HCl gas.Mineral Processing and Extractive Metallurgy, 2006, 115(3): 121-123.

［3］YUAN Gao-Qing, SHAN Yan-Juan, JIANG Huan-Feng, et al. Mg(OH)Cl/KⅠ as a highly active heterogeneous catalyst for the synthesis of cyclic carbonates from CO2 and epoxides under solventfree conditions. Chinese Journal of Chemistry, 2008, 26(5): 947-951.

［4］ 王在华, 冯 刚, 孙庆国, 等. 碱式氯化镁和氧化镁晶须的制备与表征. 盐湖研究, 2007, 15(4): 4044.

［5］ 乃学瑛, 李 洁, 边绍菊, 等. 高温熔融法制备氧化镁晶须. 无机盐工业, 2007, 39(5): 2931.

［6］HE Yun-Liang, WANG Jing-Kang, DENG Hui-Yin, et al. Comparison of different methods to prepare MgO whiskers. Ceramics International, 2008, 34(6): 1399-1403.

［7］李春忠, 古庆生, 程起林, 等. 针状碱式氯化镁的合成及形态分析. 华东理工大学学报, 2005, 31(3): 314-318.

［8］赵爱东, 申玉双, 翟学良(ZHAO Ai-Dong, et al). 一种制备氧化镁纤维的方法.无机材料学报(Journal of Inorganic Materials), 2005, 20(1): 215-219.

［9］张淑样, 于惠霞. 复分解制备高纯氢氧化镁的研究. 无机盐工业, 2007, 39(2): 43-44.

［10］Mironyuk I F, Gun’ko V M, Povazhnyak M O, et al. Magnesia formed on calcination of Mg(OH)2 prepared from natural bischofile. Applied Surface Science, 2006, 252(12): 4071-4082.

［11］Kirsh Y, Yariv S, Shoval S. Kinetic analysis of thermal dehydration and hydrolysis of MgCl2·6H2O by DAT-TG. Journal of Thermal Analysis, 1987, 32(2): 392-408.

［12］Sugimoto Kunihisa, Dinnebier Robert E, Hanson Jonathan C. Structures of three dehydration products of bischofite from in situ synchrotron powder diffraction data (MgCl2·nH2O;n=1,2,4). Acta Cryst, 2007, B63(2): 235-242.

［13］ KashaniNejad S, Ng K W, Harris R. MgOHCl thermal decomposition kinetics. Metallurgical and Materials Transactions B, 2005, 36B(1): 153-157.

［14］ KashaniNejad S, Ng K W, Harris R. Preparation of MgOHCl by controlled dehydration of MgCl2·6H2O. Metallurgical and Materials Transactions B, 2005, 35B(2): 405-406.

［15］ KashaniNejad S, Harris R. Oxides formed during the dehydration of magnesium chloride hexahydrate. Magnesium Technology in the Global Age, Canada, 2006: 81-92.

［16］黄小芳, 吴玉龙, 杨明德, 等. 水氯镁石的热解机理及动力学.过程工程学报, 2006, 6(5): 729-733.

［17］WU Yu-Long, HUANG Xiao-Fang, YANG Ming-De, et al. Study on the mechanisms and kinetics of complex’s thermal decomposition detting anhydrous magnesium chloride.Journal of Analytical and Applied Pyrolysis, 2008, 81(1): 133-135.

［18］邓晓燕. 利用综合热分析仪研究Ni(NO3)2·6H2O的热分解过程.分析仪器, 2008(2): 41-45.

［19］LONG Guang-Ming, MA Pei-Hua, WU Zhi-Ming, et al. Investigation of thermal decomposition of MgCl2 hexammoniate and MgCl2 biglycollate biammoniate by DTA-TG, XRD and chemical analysis. Thermochimca Acta, 2004, 412(1/2): 149-153.

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