Thermal Decomposition Mechanism of MgCl 2·6H2O

doi:10.3724/SP.J.1077.2010.00306

Abstract

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

CLC Number:

TQ132
O614

HUANG Qiong-Zhu,LU Gui-Min,WANG Jin,YU Jian-Guo. Thermal Decomposition Mechanism of MgCl₂·6H₂O[J]. Journal of Inorganic Materials, 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)₂prepared 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.

[1]	JIN Xihai, DONG Manjiang, KAN Yanmei, LIANG Bo, DONG Shaoming. Fabrication of Transparent AlON by Gel Casting and Pressureless Sintering [J]. Journal of Inorganic Materials, 2023, 38(2): 193-198.
[2]	ZHANG Weiwei, LU Chen, YING Guobing, ZHANG Jianfeng, JIANG Wan. Effect and Mechanism of the Surface Treatment and Gradation Filling of AlN on the Performance of Insulation Layer of Copper Clad Laminate [J]. Journal of Inorganic Materials, 2021, 36(8): 847-855.
[3]	DENG Jifeng, CHEN Shunpeng, WU Xiaojuan, ZHENG Jie, LI Xingguo. Recent Progress on Materials for Hydrogen Generation via Hydrolysis [J]. Journal of Inorganic Materials, 2021, 36(1): 1-8.
[4]	GOU Sheng-Lian, NAI Xue-Ying, XIAO Jian-Fei, YE Jun-Wei, DONG Ya-Ping, LI Wu. Preparation and Thermal Decomposition of Basic Magnesium Chloride Whiskers [J]. Journal of Inorganic Materials, 2019, 34(7): 781-785.
[5]	TIAN Xiao, DUAN Ru-Xia, ZHAO Li-Juan, NAREN Ge-Ri-Le. Anode Catalyst for the Direct Borohydride Fuel Cell [J]. Journal of Inorganic Materials, 2017, 32(12): 1233-1242.
[6]	DING Xue-Qiang, ZHANG Cheng, DONG Li-Min, WANG Chen, LIANG Tong-Xiang. Synthesis of TiO₂ Nanoparticles Using Hydrogel as Template and TiO₂ Microspheres Using Microfluidic [J]. Journal of Inorganic Materials, 2015, 30(6): 605-609.
[7]	WU Yi-Qing, NI Jian-Sen, DU Ya-Nan, HU Peng-Fei, DING Wei-Zhong, GENG Shu-Hua. Preparation of CeO₂Nanopowders by Hydrolysis and Oxidation of Cerium Carbide [J]. Journal of Inorganic Materials, 2012, 27(5): 489-494.
[8]	YU Wei-Wei, ZHANG Qing-Hong, SHI Guo-Ying, LI Yao-Gang, WANG Hong-Zhi. Preparation of Pt-loaded TiO₂ Nanotubes/Nanocrystals Composite Photocatalysts and Their Photocatalytic Properties [J]. Journal of Inorganic Materials, 2011, 26(7): 747-752.
[9]	ZHOU Yan-Ling,GAO Yuan,Lǖ Xi-Qin,CHANG Jiang. Properties of Surface Modified 45S5/PDLLA Composite Films Treated with Boiling Water [J]. Journal of Inorganic Materials, 2010, 25(4): 354-358.
[10]	YANG Qi,HU Wen-Bin. Thermal Decomposition Kinetics of γ-AlOOH Nanocrystalline Prepared by Hydrothermal Method [J]. Journal of Inorganic Materials, 2010, 25(1): 96-100.
[11]	HE Jing-Ping,ZHANG Zhao,SHEN Jun,ZHANG Yu-Ting,CHEN Yao-Han. Effects of Acid on Synthesis of Mesoporous Titania [J]. Journal of Inorganic Materials, 2009, 24(1): 43-48.
[12]	LIU Zhi-Hong,HU Lei,LIU Zhi-Yong,LI Qi-Hou. Synthesis of Microsized Co₃O₄ Octahedral by High Temperature Gas-solid Hydrolysis [J]. Journal of Inorganic Materials, 2008, 23(6): 1205-1210.
[13]	XIANG Jun,SHEN Xiang-Qian,ZHU Yong-Wei. Preparation and Magnetic Properties of Spinel-type Ferrite Fibres [J]. Journal of Inorganic Materials, 2008, 23(5): 1005-1010.
[14]	LI Yu-Chu M,HUANG Chao-Ming,WANG Sheng-Chang,WANG Jian-Xun. Hydrothermal Synthesis and Thermal Decomposing Method for Synthesizing Alumina Nanorods [J]. Journal of Inorganic Materials, 2008, 23(1): 121-124.
[15]	ZHAI Lin-Feng,SHI Tie-Jun,WANG Hua-Lin. Preparation and Formation Mechanism of Fibrous Hydrous Zirconia [J]. Journal of Inorganic Materials, 2007, 22(2): 223-226.

Thermal Decomposition Mechanism of MgCl₂·6H₂O

PDF (PC)

Knowledge

Cited

Abstract

Cite this article

share this article

References

Related Articles 15

Recommended Articles

Metrics

Comments