一种新的γ-Al_2O_3制备方法

A Novel Method for Preparing γ-Al_2O_3

经蒸发浓缩氯化铝、氨水与扩孔剂草酸铵的混合溶液,生成氢氧化铝沉淀物,再经加热分解除去NH4Cl,所得粉末成型后在550℃下煅烧转化为γ Al2O3.着重考察扩孔剂加入量,分解温度等对产品性质的影响.与常规制备γ Al2O3方法比较,本方法省去了老化、过滤、洗涤等步骤,具有缩短制备周期、保护环境等优点.本方法所制γ Al2O3孔体积大,孔分布集中,压碎强度高.

A novel method for preparingγAl2O3 is provided with the procedure as follows :(1) a mixing solution composed of AlCl3,NH+4,H2O and ammonium oxalate is concentrated by heating and resulting in the deposition of Al(OH)3;(2)drying the deposit;(3)decomposing the deposit and NH4Cl being retrieved;(4)the powder from step(3)being pelleliged(5)calcining the pellet at 550℃ for 4hr.Compared with the usual technology,this new method has the advantages of needlessness of preparing steps such as aging,filter and washing,and the dispose of the washing liquid.The γAl2O3 obtained by the method is characterized by large pore volume,narrow pore distribution and high crushing strength for pellet.