Abstract: Alumina were prepared with aluminium sulfate as aluminium source, ammonium bicarbonate as precipitant, using substep aging method and L9 (34) orthogonal table. Factors inculding ammonium bicarbonate concentration, reaction temperature, pH and n(HCO-3)/n（Al3+） were studied. The alumina were characterized by the N2 physisorption and bulk density measurement, XRD and SEM as well. After orthogonal analysis, reaction temperature and pH have significant effect on textile properties of γAl2O3. Optimum preparation conditions were determined by macropore formation, and they were as follows: reaction temperature 75 ℃, pH 8.5, the concentration of ammonium bicarbonate 2 mol/L, n(HCO-3)/n（Al3+） ratio 075. Besides that, Y5 has big pore volume up to 2.02 mL/g, bimodal pore distribution and fibrous particles which have uniform size around 1 μm.

Key words: Orthogonal experiment, γ-alumina, Bulk density, Pore volume, N2 adsorptiondesorption isotherm

摘要： 以硫酸铝为铝源、 碳酸氢铵为沉淀剂, 采用分步老化法, 使用L 9( 3 4) 正交实验考察了碳酸氢铵物质的
量浓度、 反应温度、 p H和n( HCO- 3 ) /n( A l 3+) 等因素对制备毭 灢 A l 2O3 的影响, 并对所得 A l 2O3 进行了 N2 物理吸附
表征和堆积密度测量, 对 Y 5样品进行了X射线衍射和电镜扫描, 由正交实验结果分析得出温度和p H 对毭 灢 A l 2O3
的结构影响很大。大孔容氧化铝的制备最佳条件为: 反应温度为7 5曟, p H为8. 5, 碳酸氢铵物质的量浓度为2m o l /
L, n( HCO- 3 ) /n( A l 3+) 为0. 7 5。其中, 样品 Y 5孔容达2. 0 2mL / g, 具有双峰孔分布, 粒子呈纤维状, 大小均匀, 粒径
为1毺m左右。

关键词: 正交实验, 氧化铝, 堆积密度, 孔容, N2 吸附 - 脱附