菱镁矿石热分解特性及模型研究  

Characteristic and Model of Thermal Decomposition of Magnesite

作　　者：焦楷 袁章福 张利娜 谢珊珊 李林山 隋殿鹏[5] 

机构地区：[1]北京科技大学钢铁共性技术协同创新中心,北京100083 [2]北京科技大学工程技术研究院,北京100083 [3]冶金工业规划研究院,北京100711 [4]大石桥市信威耐火材料有限公司,辽宁营口115103 [5]东北大学理学院化学系,沈阳110003

出　　处：《有色金属（冶炼部分）》2018年第1期64-68,共5页Nonferrous Metals（Extractive Metallurgy)

基　　金：国家科技支撑计划项目(2014BAB02B02;2012BAB06B02); 国家自然科学基金资助项目(U1560101)

摘　　要：以粒径900μm的菱镁矿为原料,采用TG-DSC法研究了菱镁矿石热分解模型。结果表明,菱镁矿的开始分解温度为800K左右,950K左右时分解完全,反应达到平衡。DSC曲线只有一个向下的峰与TG曲线失重台阶相对应,说明菱镁矿分解反应是一步反应,分解产生二氧化碳需要吸收热量。且随着升温速度的提高,菱镁矿需要在更高的温度下才能达到相同的分解程度。通过Flynn-Wall-Ozawa和Kissinger动力学分析方法计算菱镁矿热分解的平均活化能为260.54kJ/mol,并利用Malek法分析菱镁矿热分解机理,菱镁矿分解为二维相边界反应,圆柱形对称模型,积分形式机理函数为G(α)=2[1-(1-α)1/2]。Thermal decomposition model of magnesite was investigated by TG-DSC analysis with magnesite（900μm）as raw material.The result shows magnesite begins to decompose at about 800 Kand completely decomposes at around 950 K.DSC curve shows one downward peak corresponding to weight loss process,indicating that decomposition reaction of magnesite is one-step and endothermic.With increase of heating rate,magnesite needs higher temperature to achieve the same degree of decomposition.Average activation energy of thermal decomposition of magnesite is 260.54 kJ/mol calculated by Flynn-Wall-Ozawa Method and Kissinger Method.Magnesite decomposition reaction model was discussed by Malek Method.Thermal decomposition reaction of magnesite is two-dimensional phase boundary reaction as cylindrical symmetric model.The kinetic equation of magnesite is G（α）=2[1-（1-α）1/2].

关 键 词：菱镁矿 TG-DSC 热分解动力学 机理函数 

分 类 号：TQ175.4[化学工程—硅酸盐工业]