为了给西藏卡玛多微晶菱镁矿的开发利用提供理论指导，以粒径≤0.5 mm的西藏卡玛多微晶菱镁矿为原料，采用热重（TG）曲线研究了不同升温速率条件下微晶菱镁矿的热分解特性，并进行了热力学计算，同时根据微晶菱镁矿的热重实验数据，采用非等温热重分析方法（FWO法和KAS法）计算了不同升温速率条件下微晶菱镁矿的热分解活化能，最后分析了微晶菱镁矿的分解产物氧化镁的微观形貌。分解热力学研究结果表明:随着升温速率的增大，微晶菱镁矿分解所需的热量逐渐增大，当升温速率从2 ℃/min逐渐增加到10 ℃/min时，分解所需的热量从187.93 kJ/mol逐渐增大到207.08 kJ/mol。分解动力学研究结果表明:采用FWO法和KAS法求得的热分解活化能与分解率的变化趋势相近，当分解率≤30%时热分解活化能随着分解率的升高而急剧下降，当分解率>30%时热分解活化能随着分解率的升高而下降缓慢，且逐渐趋于平缓。微晶菱镁矿分解后的微观形貌表明，升温速率越大，其分解产物氧化镁的晶粒越大。

In order to provide theoretical guidance for the development and utilization of Tibet Kamado microcrystalline magnesite，the thermal decomposition characteristics of Tibet microcrystalline magnesite with particle size ≤0.5 mm were studied by thermogravimetric（TG） curve under different heating rates and the thermodynamic calculation was carried out.At the same time，according to the thermogravimetric test data of microcrystalline magnesite，the activation energy of thermal decomposition of Tibet microcrystalline magnesite at different heating rates was calculated by non-isothermal thermogravimetric analysis（FWO method and KAS method）.Finally，the micromorphology of magnesium oxide，the decomposition product of Tibet microcrystalline magnesite was analyzed.The results of decomposition thermodynamics showed that with the increase of heating rate（from 2 ℃/min to 10 ℃/min），the heat required for the decomposition of the microcrystalline magnesite was increased gradually（from 187.93 kJ/mol to 207.08 kJ/mol）.The results of reaction kinetics showed that the activation energies of the microcrystalline magnesite calculated by the FWO method and the KAS method were similar.When the decomposition rate was ≤ 30%，the activation energy of thermal decomposition was decreased sharply with the increase of decomposition rate.When the decomposition rate was >30%，the activation energy of thermal decomposition was decreased slowly with the increase of decomposition rate and gradually became gentle.The microscopic morphology of microcrystalline magnesite decomposition showed that the greater the heating rate，the larger the magnesia grains of the decomposition product.