中文摘要：

采用X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、热重分析（TGA）和扫描电子显微镜（SEM）综合分析水热温度对硫酸铝水解产物物相的影响及其反应机理,同时通过低温氮气吸附法（BET）测定产物孔结构。结果表明：水热温度t≤96℃时,Al_2（SO_4）_3水解产物为无规则团聚的非晶态氢氧化铝;t≥120℃,氢氧化铝不稳定,存在再溶解-再沉淀过程,非晶态氢氧化铝向NaAl_3（SO_4）_2（OH）_6转化;t=180℃时,通过奥氏熟化,Al_2（SO_4）_3水解产物转变为斜方六面体NaAl_3（SO_4）_2（OH）_6,择优向（113）面生长。BET结果表明,水热温度t≤96℃时,产物孔径分布不均匀,t≥120℃时,产物孔径分布窄而均匀,且t=120℃时,产物比表面积最大为91.99 m2·g（-1）。

英文摘要：

The effect of hydrothermal temperature on the phase of the hydrolyzate of aluminum sulfate and the reaction mechanism was analyzed synthetically by X-ray diffraction （XRD） , Fourier transform infrared spectros- copy （FT-IR） , thermogravimetric analysis （TGA） and scanning electron microscopy （SEM）. Pore structure of products were analyzed by low temperature nitrogen adsorption method （BET）. The results showed that the ag- gregated and amorphous aluminum hydroxide was obtained when the hydrothermal temperature was less than or equal to 96 ℃. Aluminum hydroxide is unstable, and there is a redissolution re-precipitation process at 120 ℃. Then, amorphous aluminum hydroxide hydrothermally crystallized and transformed into NaAl3 （SO4 ）2 （OH）6. Under the hydrothermal temperature of 180℃ , the hydrothermal products of aluminum sulfate transformed into NaAl3 （SO4）2 （OH）6 with hexahedral structure by Ostwald ripening process and the preferred direction is （113）. BET results showed that pore size distribution is not uniform when the hydrothermal temperature was less than or equal to 96 ℃. When the hydrothermal temperature is greater than or equal to 120 ℃ , pore distribution is narrow and uniform. And the maximum specific surface area of the product was 91.99 m2 · g^-1 synthesized at 120 ℃.