中国西南地区炼镁用白云石热分解过程动力学研究  

Kinetic Mechanism Analysis of the Thermal Decomposition Process of Magnesium-smelting Dolomite in Southwest China

作　　者：刘欢[1] 龙思远[1,2] 周玉乐[1] 吴星宇[1] 游国强[1,2] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]国家镁合金材料工程技术研究中心,重庆400030

出　　处：《矿物学报》2014年第1期35-39,共5页Acta Mineralogica Sinica

基　　金：国家自然科学基金项目(批准号:51105393);中央高校基本科研业务基金(编号:CDJXS11132226)

摘　　要：对重庆某地区的白云石进行TG-DTG热分解实验,研究其热分解机理。结果表明:该地区白云石为钙质白云石,其热分解过程包括2个阶段。随升温速率的加快,2个热分解阶段的分解温度也相应地升高,但每个阶段的前后温度差基本保持不变;2个热分解过程分别遵循三维扩散(球形对称)和相界反应(圆柱形对称)机理,热分解活化能E分别为348.5 kJ/mol和369.2 kJ/mol。基于研究结果,建立了白云石热分解过程每个阶段的动力学模型。Thermal decomposition reactions of dolomite samples in the area of Chongqing were investigated by simultaneous TG/DTG experiments, to study the thermal decomposition mechanism. Results show that dolomite samples are calcareous dolomite, and two steps are detected during the thermal decomposition process. With the increase of the heating rate, the decomposition temperature of two thermal decomposition processes will rise accordingly, but the temperature interval of the each single process remains basically constant; Two thermal decomposition stages follow separately the three-dimensional diffusion （tridimensional particle shape） and phase boundary controlled reaction （contracting area-bidimensional shape） model, and the values of the activation energies for the thermal composition were calculated to be 348.5 kJ/mol and 369.2 kJ/mol, respectively. Finally, the kinetic models of different stages of thermal decomposition were established.

关 键 词：白云石 热分解 动力学 机理 

分 类 号：P579[天文地球—矿物学] TF822[天文地球—地质学]