【作者】 党力； 乃学瑛； 董亚萍； 李武；

【Author】 Li Dang;Xueying Nai;Yaping Dong;Wu Li;Qinghai Institute of Salt Lakes, Chinese Academy of Sciences;Uinversity of Chinese Academy of Sciences;

【机构】 中国科学院青海盐湖研究所； 中国科学院大学；

【摘要】 无水碳酸镁具有热分解温度高,分解吸热量大,分解后产物氧化镁活性高等优点,被广泛应用于绝热、耐高温的防火保温材料中^[1-2]。本文以硫酸镁为原料、尿素为沉淀剂、氢氧化钠为助剂,采用微波加热一步制备出形貌规则、尺寸均一的无水碳酸镁粉体。利用扫描电镜（SEM）和X射线衍射（XRD）对产物的结构、形貌和成分进行了表征。结果表明,当硫酸镁:尿素:氢氧化钠的摩尔比为1:5:1时,在160℃微波加热条件下反应30min,即可得到立方体状无水碳酸镁粉体,其边长为4.0μm左右;随着反应时间的延长,产物转化为近球形的多面体结构,且尺寸明显增大。所得产物组成均为无水MgC O₃。更多还原

【Abstract】 Anhydrous magnesium carbonate has been widely used in fireproof and heat insulting materials since its high caloric receptivity. Besides, highly active magnesia left after thermal decomposition. In this paper, uniform Mg CO₃ power was prepared by microwave-assisted method using Mg SO₄ as raw materials, urea as a precipitation agent and Na OH as assistant agent. The product was characterized by SEM and XRD. The results showed that cubelike Mg CO₃ was obtained after 30 min microwave heating at 160℃, when the molar ratio of Mg SO₄: CO（NH₂）₂: NaO H was 1:5:1.The length of a side of the cubic was about 4.0 μm. It was also noticed that the cubelike MgC O₃ converted to near spherical polyhedron with the prolonging of reaction time. The size of the powder also increased. The composition of all products was anhydrous MgCO₃.更多还原