花状高纯一水软铝石制备及形成机理

摘要

以氢氧化铝、硫酸和尿素为基本原料,首先使用硫酸溶解氢氧化铝,经特殊除杂工艺制备出高纯硫酸铝,而后以尿素为沉淀剂水热合成一水软铝石.采用X射线衍射仪(XRD)、X射线荧光光谱仪(XRF)、等离子体发射光谱仪(ICP)、扫描电镜(SEM)等对水热产物进行成分、纯度、相态和形貌分析.结果表明,在低温状态下水热产物为球形结构的硫铝无定形胶体,可用化学表达式表示为Al2O3·0.6SO3·2.2H2O;在150℃反应5h,可以获得纯度为99.999％的花状一水软铝石.另外,还探讨了花状一水软铝石的形成机理.%High-purity boehmite was synthesized using aluminum hydroxide,sulfuric,and urea as raw materials.Firstly,aluminum hydroxide was dissolved by sulfuric,and then high-purity aluminum sulfate was prepared by special impurity removal process.At the last,boehmite was synthesized by hydrothermal method with urea as the precipitator.The composition,purity,phase,and morphology of hydrothermal products were characterized by XRD,XRF,ICP,and SEM etc..Results showed that hydrotherrnal product was spherical amorphous gel (Al2O3· 0.6SO3· 2.2H2O) at low temperature,and flower-like boehmite with purity of 99.999％ was obtained at 150 ℃ for 5 h.Moreover,formation mechanism of flower-like boehmite was also discussed.