重庆地区炼镁用白云石热分解动力学及影响因素研究

对重庆某地区的白云石进行TG-DTG热分解实验,研究其热分解机理和影响该机理的实验因素。结果表明:该地区白云石热分解过程遵循三维扩散(球形对称,Jander方程)机理,热分解活化能E=357.4 kJ/mol,基于研究结果,建立了白云石热分解过程的动力学模型;进行试样颗粒粒径、质量、SiO2含量和保护气体流速的对比实验。结果表明:试样颗粒粒径的增大和试样质量的增加,均会引起白云石热分解活化能值的升高,而白云石中SiO2含量以及保护气体流速的变化对白云石热分解活化能影响很小。

Kinetic mechanism and influential factors of thermal decomposition process of magnesium-smelting dolomite in Chongqing

Thermal decomposition reactions of dolomite in Chongqing were investigated by TG/DTG experiments to study the thermal decomposition mechanism and influential factors. The results show that the thermal decomposition process of the dolomite follows the three-dimensional diffusion(tridimensional particle shape,Jander equation)model,and the value of activation energy for thermal decomposition is calculated to be 357.4 kJ/mol. The kinetic model of thermal decomposition process was established based on the above research results. The contrast experiments of sample particle size,weight,SiO2content and the flow rate of protective gas show that the value of the activation energy for thermal composition will be increased significantly with the increase of particle size and weight,however,the change of SiO2content of dolomite and the flow rate of protective gas has little impact on the activation energy of thermal decomposition of dolomite samples.