菱镁矿热分解的动力学研究

发布时间：2018-03-26 05:18

本文选题：菱镁矿　切入点：动力学　出处：《硅酸盐通报》2017年06期

【摘要】：利用热重(TG)分析法,对不同粒度菱镁矿的热分解过程进行研究。根据Flynn-Wall-Ozawa法,拟合计算得到不同粒度菱镁矿热分解的活化能和指前因子。采用Thermo-kinetics软件对可能性最大的5种动力学机理函数进行拟合,根据相关系数最大的原则确定最佳分解机理。研究结果表明:菱镁矿热分解的活化能随菱镁矿粒度的增大而减小,当菱镁矿的粒度由小增大时,控制其热分解过程的机理由化学反应逐渐向颗粒内部的传热和CO2的扩散传质转变;其热分解过程的最可几机理函数为R3模型,即三级相边界扩散反应,函数方程为G(α)=1-(1-α)~(1/3)。
[Abstract]:The thermal decomposition process of magnesite with different granularity was studied by thermogravimetric TG-analysis. According to Flynn-Wall-Ozawa method, The activation energy and preexponential factor of thermal decomposition of magnesite with different sizes were calculated by fitting. Five kinds of kinetic mechanism functions with the greatest possibility were fitted by Thermo-kinetics software. According to the principle of maximum correlation coefficient, the optimum decomposition mechanism is determined. The results show that the activation energy of magnesite thermal decomposition decreases with the increase of magnesite particle size, and when the magnesite size increases from small to small, The mechanism of controlling the thermal decomposition process is gradually transformed from chemical reaction to heat transfer inside particles and diffusion and mass transfer of CO2, and the most probable mechanism function of the thermal decomposition process is R3 model, that is, the third-order phase boundary diffusion reaction. The function equation is G1 (伪 -N-1) -1- 伪 ~ (1 +) 1 / 3 ~ (-1).
【作者单位】：辽宁科技大学高温材料与镁资源工程学院;
【基金】：国家科技支撑计划项目(2014BAB02B01)
【分类号】：TD912

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