拟薄水铝石胶溶指数影响因素的研究

采用铝酸钠-硫酸铝中和法制备了拟薄水铝石,研究了制备过程中铝酸钠溶液质量浓度、中和温度、中和pH及老化时间等制备条件对拟薄水铝石胶溶指数的影响,并考察了拟薄水铝石的胶溶指数对Al2O3载体物性的影响。实验结果表明,当铝酸钠溶液质量浓度(以Al2O3计)为100～180 g/L、中和温度为55～70℃、中和pH为6.5～8.5、老化时间60～120 min的条件下,可得到胶溶指数较高的拟薄水铝石。拟薄水铝石的胶溶指数对Al2O3载体的压碎强度影响很大,一般要得到压碎强度大于60 N的Al2O3载体,拟薄水铝石的胶溶指数要大于85%;拟薄水铝石的胶溶指数对Al2O3载体的吸水率、比表面积和孔体积影响较小。

Factors Affecting the Dispersion Index of Pseudo-Boehmite

Pseudo-boehmite was prepared through sodium aluminate-aluminum sulfate neutralization method.The factors affecting the dispersion index of the prepared pseudo-boehmite,namely sodium aluminate solution mass concentration(based on Al2O3),precipitation temperature,precipitation pH and aging time,were investigated.The effects of the dispersion index on Al2O3 support properties were studied.Under the conditions of sodium aluminate solution mass concentration 100-180 g/L,precipitation temperature 55-70 ℃,precipitation pH 6.5-8.5 and aging time 60-120 min,the pseudo-boehmite with large dispersion index could be prepared.The dispersion index influenced the crush strength of the alumina support obviously.In order to prepare alumina support with crush strength more than 60 N,the dispersion index of the prepared pseudo-boehmite must be higher than 85%.The dispersion index has little influence on water absorption rate,specific surface area and pore volume of the prepared alumina support.