TG-DTG和FTIR法研究碳酸镁水合物的热分解  

Study on the Thermal Decomposition of Magnesium Carbonate Hydrates by TG-DTG and FTIR

作　　者：任宏瑞[1,2] 陈镇[2] 党杰[2] 吴玉龙[2,3] 杨明德[2] 陈津[1] 胡湖生[2] 

机构地区：[1]太原理工大学材料科学与工程学院,太原030024 [2]清华大学核能与新能源技术研究院,北京100084 [3]清华大学精细陶瓷北京市重点实验室,北京100084

出　　处：《太原理工大学学报》2013年第5期560-565,共6页Journal of Taiyuan University of Technology

基　　金：国家"十一五"科技支撑重点项目(2008BAB35B05)

摘　　要：以水氯镁石(MgCl2.6H2O)为镁源、Na2CO3为沉淀剂,利用沉淀法分别在30℃和90℃下制备得到碳酸镁水合物:三水碳酸镁和碱式碳酸镁。采用TG-DTG和热重跟踪法对此碳酸镁水合物的热分解进行分析。采用FTIR和SEM对热重跟踪实验中试样的组成和形态进行分析。结果表明:三水碳酸镁和碱式碳酸镁分别分5个和2个阶段进行分解,且二者脱水和脱二氧化碳的温度区间几乎相同;对于中间相的组成,FTIR分析结果与TG数据的计算结果一致;SEM图形象地呈现出了二者在轻烧过程中的形态变化。这将为盐湖水氯镁石制备高纯镁砂过程中轻烧工艺的确定提供一定的理论依据。Nesquehonite and hydromagnesite （magnesium carbonate hydrates） have been synthesized by the reaction of MgCl2 and Na2CO3 at 30℃ and 90℃, respectively. The thermal decomposition of magnesium carbonate hydrate was investigated by TG-DTG and thermogravimetric tracking experiment. In the tracking experiment, the composition and morphology were analyzed by FTIR and SEM. The results showed that the thermal decomposition process of nesquehonite and hydromagnesite can be divided into five stages and two stages, and the dehydration and decar- bonation temperature range of them are similar respectively. For the composition of intermediate phase, the FTIR analysis results were consistent with the calculation results from TG data. The SEM images presented morphological changes of them in the calcining process. This will provide theory foundation for the calcining condition selection in the preparation of high-purity magnesia using bischofite from the salt lake.

关 键 词：三水碳酸镁 碱式碳酸镁 镁砂 TG—DTG FTIR 

分 类 号：O611.65[理学—无机化学]