氧化镁常压水合法制备氢氧化镁的过程分析

以活性氧化镁为原料,在碱性环境中用常压水合法制备纳米氢氧化镁,通过实时取样,结合扫描电子显微镜(SEM)和X射线衍射(XRD)表征其形貌和结构,探索氧化镁的水化合成过程和相关机理。结果表明:在水合时间2 h后,体系中氧化镁已经全部转化生成氢氧化镁,反应时间短。水合反应体系中OH-使氢氧化镁极性面稳定,未发生第Ⅱ类聚集生长,晶体呈片状结构。随着时间增长,氢氧化镁颗粒出现大颗粒长大,小颗粒缩小的现象,发生第Ⅰ类聚集生长,但平均粒径不变,为18.7 nm。

The Process Analysis of Hydrating Magnesium Oxide to Prepare Magnesium Hydroxide under the Ordinary Pressure

Using the active magnesium oxide as raw materials,NaOH as the modifier,hydrates to prepare nano magnesium hydroxide under the ordinary pressure.Through real-time sampling,scanning electron microscope test(SEM) and X-ray diffraction (XRD) are used to characterize morphology and structure of the products,so that we can explore the magnesium oxide hydrated process and the related mechanism.The results of the research show that:magnesium oxide turn to magnesium hydroxide all after two hours of reaction,and it takes a short time.In the hydrated process,OH-makes the polar face of magnesium hydroxide stable so that there is no Ⅱ kind of clustered growth happened,and crystals are tend to be flake.With increase of time,large particles of magnesium hydroxide grow larger while small ones shrink,and this is the Ⅰ kind of clustered growth.The average particle diameter remains 18.7 nm.