为对比水镁石与菱镁矿分解产物的特性差异，首先以水镁石为原料，利用热重分析仪、X射线衍射仪、物理吸附仪等对其煅烧过程中分解率、物相组成、微观结构等性质进行表征，研究了CO₂气氛、煅烧温度、保温时间对其产物活性的影响，并与菱镁矿煅烧产物进行对比。结果表明：随着煅烧温度的增加，水镁石分解率逐渐升高，产物的比表面积逐渐降低，而晶粒尺寸和显色时间呈现先降低后增加的趋势，700 ℃时显色时间最短，活性最佳，晶粒尺寸最小，活性由分解率和微观结构共同决定；相同煅烧温度下（700 ℃），保温时间的延长对分解率及产物的性质几乎没有影响；与氮气中的结果相比，CO₂气氛中水镁石分解温度升高了约65 ℃，产物晶粒尺寸降低，比表面积和活性增加；水镁石煅烧产物活性较菱镁矿的更高，这主要是因为水镁石分解后活性氧化镁含量更高。该研究结果将为水镁石资源的利用提供参考数据。

To understand the difference in the characteristics of calcination products between brucite and magnesite，firstly，using brucite as the raw material，the decomposition rate，phase composition，microstructure and other properties during the calcination process were characterized using thermogravimetric analyzer，X-ray diffractometer，physical adsorption instrument，etc.The effects of CO₂ atmosphere，calcination temperature，and holding time on the activity of the product were studied，and compared with the calcined product of magnesite.The results showed that as the calcination temperature increased，the decomposition rate of brucite increased，and specific surface area decreased gradually.The grain size and coloration time decreased sharply and then increased before and after the calcination temperature reached 700 ℃.The activity was determined by both decomposition rate and microstructure.At the same calcination temperature（700 ℃），the increase in holding time had almost no effect on the decomposition rate and product properties.Compared to the results under the atmosphere of N₂，the decomposition temperature of brucite increased by 65 ℃，the grain size reduced，and the specific surface area and activity increased in the presence of CO₂.The activity of products derived from brucite decomposition was higher obviously than that from magnesite，mainly due to the higher content of active MgO after calcination of brucite.This study would provide basic data for the utilization of brucite resources.