Synthesis of NaY Zeolite by In-situ Crystallization of Sepiolite-group Attapulgite

A novel NaY zeolite has been hydrothermally synthesized by in-situ crystallization using roasted attapulgite and kaolin as raw materials.The as-synthesized samples were characterized by XRD,SEM and N2 adsorption-desorption testing.The effects of material ratio and crystallization temperature on the relative crystallinity of NaY zeolite were investigated.The results show that the relative crystallinity of NaY zeolite increases with n(SiO2)/n(Al2O3) decline.Appropriate alkalinity [n(Na2O)/n(SiO2),n(Na2O)/n(H2O)] can increase the relative crystallinity of NaY zeolite.It has been found that n(SiO2)/n(Al2O3) plays a dominant role in the relative crystallinity of NaY zeolite.The crystallization temperature is the most important dynamic factor affecting the relative crystallinity of zeolite NaY.As the crystallization temperature increasing,the relative crystallinity of NaY zeolite increases significantly.When the crystallization temperature reaches 100 ℃,a NaY zeolite with high relative crystallinity can be obtained.