熔盐法制备氧化镁粉体及其活性研究

以MgCl2-6H2O、CaCO3和LiCl为原料，采甩熔盐法制备了MgO粉体。通过热重．差示扫描热量计（TG—DSC）、X射线衍射仪（XRD）、场发射扫描电子显微镜（SEM）等手段对反应过程及产物进行了分析和表征，同时采用水解动力学分析法研究了煅烧温度和时间对氧化镁粉体活性的影响。TG-DSC分析表明，650℃时CaCO3可完全反应；XRD分析表朝，450℃保温3h热处理，产物中有MgO生成。650℃保温3h热处理，产物经无水乙醇洗涤后，全部为MgO晶体；SEM分析表明，所制备的氧化镁形貌为颗粒状，形状不规整，大小介于50-250nm之间；水解动力学分析法表明，当温度大于500℃、保温时阕超过3h后，随着热处理温度的升高和时间的延长，MgO粉体活性下降。

Study on Preparation of MgO Ultrafine Powder by Molten Salt Method and Its Activity

MgO powders were prepared through molten salt synthesis with MgCl2·6H2O, CaCO3 and LiCI. The reaction process and product were analyzed and characterized by using TG-DSC, XRD and TEM. The influences of the calcining temperature and time on the activity of MgO powders were also studied by hydrolysis kinetics. The TG-DSC results showed that： When the temperature reached the 650 ℃, the calcium carbonate decomposed completely. The XRD results showed that： we can obtain product of MgO. If the materials have been prepared at 450 ℃ for 3 h. If the materials have been prepared at 650 ~C for 3 h, and the product was washed in anhydrous alcohol, we completely obtained MgO Crystal The SEM results showed that： The product shape for the granular and irregularity shape, with the size of about 50-250 nm. The hydrolysis kinetics results also showed that： when the temperature was up to or higher than 500 ℃ and heat preservation time is up to or higher than 3 h, the activity of MgO would decrease with the increase of temperature and holding time.