关键词: 拟薄水铝石, 正交试验, 比表面积, 孔体积, 硫酸铝

Abstract:

Pseudo-boehmite was prepared by NaAlO2-Al2(SO4)3 method. The effect of process parameters on the physicochemical properties of pseudo-boehmite was studied by the orthogonal test. Techniques such as XRD, BET, and SEM were employed to characterize the content of gibbsite, crystal phase, pore structure, and apparent morphology. The results of orthogonal test show that the contents of gibbsite of the samples were closely related to the gelation pH. The main factors affecting the pore properties of pseudo-boehmite were the gelation pH value, the gelation temperature and time, the content of Al2(SO4)3 and NaAlO2, and the aging time. Under the conditions of pH value around 8.5, the gelation temperature higher than 70℃, the content of Al2(SO4)3 larger than 130 g?L-1, the content of NaAlO2 around 200 g?L-1, the gelation time of 60 minutes, and the aging time around 5 minutes, the pseudo-boehmite with specific surface area larger than 280 m2?g-1 and pore volume larger than 0.70 mL?g-1 are obtained. The grain shape of pseudo-boehmite with high specific surface area and large pore volume likes rods which are loosely stacked and form large gaps.

Key words: pseudo-boehmite, orthogonal test, specific surface area, pore volume, aluminum sulfate