利用热同步分析仪，在纯二氧化碳气氛、升温速率为10~30 K/min的条件下，对4种不同粒径的石灰石进行热分解特性研究，并采用改进的双外推法求解石灰石的热分解反应动力学参数。数据分析结果表明：石灰石粒径与其分解所需的活化能成正比例关系，粒径越小所需要的活化能越小，反之越大；升温速率越快，对应的分解反应温度越高，达到同一转化率所需要的时间越短，说明反应进程越快；纯二氧化碳气氛下，4种不同粒径的石灰石热分解均遵循随机成核和随后生长模型，不同粒径的石灰石对应不同的反应级数，反应级数变化范围为1/2~2；不同升温速率下石灰石热分解反应速率不同，粒径范围为38~250 μm的石灰石热分解反应速率受界面化学反应控制。

The thermal decomposition characteristics of four limestones with different particle sizes were investigated by using thermal synchronous analyzer under pure carbon dioxide atmosphere with heating rate of 10~30 K/min.A modified double extrapolation method was used to solve the kinetic parameters of the thermal decomposition reaction of limestone.The results of data analysis showed that：the limestone particle size was proportional to the activation energy required for its decomposition，the smaller the particle size，the smaller the activation energy required，and vice versa.The faster the heating rate，the higher the corresponding reaction temperature，and the shorter the time required to reach the same conversion rate，indicating the faster the reaction process.The thermal decomposition of limestone with four different particle sizes under pure carbon dioxide atmosphere was followed the random nucleation and subsequent growth model，and different the reaction rate of limestone thermal decomposition under different heating rates was different，and reaction order range was 1/2~2.The thermal decomposition reaction rate of limestone was different at different heating rates，the thermal decomposition reaction rates of limestone with particle size of 38~250 μm were controlled by interfacial chemical reaction.