Ca_2B_2O_5·H_2O的热分解过程研究

Study on Thermal Decomposition Process of Ca_2B_2O_5·H_2O

采用水热法制备了片状Ca_2B_2O_5·H_2O水合硼酸盐前驱体,利用XRD、FI-IR及SEM等手段对样品进行了表征,利用TG-DTA热重分析法对Ca_2B_2O_5·H_2O的脱水热分解进行了分析。结合热分析结果和不同温度下焙烧产物的物相表征结果,研究上述硼酸钙的热分解过程,结果表明,热分解过程大致分为三个阶段:第一阶段硼酸钙失去表面的吸附水,第二阶段硼酸钙失去结晶水形成无定形的无水硼酸钙,第三阶段无水硼酸钙由无定形转化为结晶。

One kind of hydrated borate precursors,Ca2 B2 O5·H2 O in flake form,was prepared using hydrothermal method. The precursor was characterized by XRD,FI-IR and SEM. The dehydration thermal decomposition process of the precursors was analyzed by TG-DTA. Combined with the thermal analysis and the phase characterization of the calcined products at different temperatures,the thermal decomposition process of the above calcium borate was studied,and the results showed that the thermal decomposition processes contained three stages: in the first stage,the calcium borate lost the adsorbed water on the surface;in the second stage,calcium borate lost crystal water to form amorphous anhydrous calcium borate;in the third stage,anhydrous calcium borate was converted to crystalline from amorphous.