关键词: 氧化铝, 比表面积, 孔体积, 脂肪醇, 乳化剂

Abstract: Aiming at the difficult problem of preparing high-purity alumina with large specific surface area, large pore volume and large pore size, the effects of organic fatty alcohol on the specific surface area, pore volume and the most probable pore diameter of alumina during the preparation of high-purity alumina by alkoxy aluminum hydrolysis were investigated, and the influence mechanism was explored. The results showed that the addition of fatty alcohol and emulsifier at the same time was beneficial to the dispersion of alcohol in the slurry of aluminum hydroxide precursor, and more large pores could be formed effectively by drying and calcination, so that the specific surface area, pore volume and the most probable pore diameter could increase at the same time. The higher the amount of alcohol or emulsifier, the better the effect of pore enlargement, and the higher the carbon number of fatty alcohol, the better the effect of pore enlargement. As an additive, n-hexanol was better than isopropanol, n-butanol and n-amyl alcohol in pore enlargement. The addition of fatty alcohol did not increase the residual carbon content of alumina products and had no effect on the purity of alumina. Through optimization of process conditions, high-purity alumina with high specific surface area ≥ 270 m²/g, pore volume ≥ 0.80 cm³/g and the most probable pore diameter ≥9 nm could be obtained by this method.

Key words: alumina, specific surface area, pore volume, fatty alcohol, emulsifier