中文摘要：

利用TG-DSC热分析技术,对菱镁矿的热分解过程进行了研究。结果表明,菱镁矿的热分解为一步反应。由Kissinger与Ozawa-Doyle两种方程求得菱镁矿热分解反应的表观活化能和指前因子（lg A）分别为177.14 kJ/mol和7.39 s-1。根据Coats-Redfern方程,用常见的固体热分解机理函数分别进行了多元线性回归,进一步利用Malek法确定了菱镁矿热分解过程属于三维扩散机理D3,并获得了分解过程的微分方程。采用DSC方法测试了碳酸镁的比热容,用最小二乘法拟合曲线,获得其比热容表达式。

英文摘要：

Thermal decomposition process of magnesite was investigated by means of TG-DSC.Results showed that magnesite decomposition was in one phase reaction.The apparent activation energy and pre-exponential factor（lg A） were calculated by Kissinger and Ozawa-Doyle equations,and the values of them were 177.14 kJ/mol and 7.39 s-1,respectively.According to Coats-Redfern equation,multiple linear regressions were carried out with common mechanism functions of solid thermal decomposition.Furthermore,it was obtained from Malek method that the process of magnesite thermal decomposition belonged to three-dimensional diffusion mechanism（D3）.And then,the differential equation was deduced as well.The specific heat capacity of MgCO3 was measured by means of DSC.And the expression of specific heat capacity was obtained by least square curve fitting method.