Preparation Of Y Zeolite By Hydrothermal Method Using Stellerite Of Ziyuan County As Materials

On the basis of integrated analysis of a great deal of literatures and datas about the synthesis and applications and formationg mechanism of zeolite sieves as well as the theories of crystal growth model, this paper studies the resource characteristics of the stellerite in Ziyuan county of Guangxi and the formation mechanism and crystal growth model of Y zeolite molecular sieves that are prepared in hydrothermal system of taking the stellerrite. The main contents of the paper were as follows:The resource characteristics of the stellerite in Ziyuan county of Guangxi were studied by XRD, chemical compositions and IR. The zeolite in Ziyuan county of Guangxi is stellerite rather than stlbite. The stellerite that has calcium, iron and etc, they affect the synthesization and whiteness of zeolite. So, it was to purify stellerite. This paper was to purify stellerite with hydrochloric acid.Taking the stellerite (pretreated) as the feedstock, Y zeolite was prepared by using the hydrothermal method. It was discussed how constitutes of the reaction mixture and hydrothermal conditions influence the hydrothermal preparation of Y zeolite, the best technical parameters of hydrothermal preparation of Y zeolite were confirmed.The mechanism of the synthesis of Y zeolite from stellerite and the crystal growth model of Y zeolite were measured by SEM, XRD and IR. With the dissolution of feedstock (pretreated) in the alkali solution, Solid SiO₂ and Al₂O₃ were transformed liquid SiO₂ and Al₂O₃. When the concentration of liquid silicate ions and aluminate ions reach to the saturation of the formation of Y zeolite, firstly the Y zeolite nucleuses were formed at the surface of feedstock, and then the gels crystallized at the seeds and formed zeolite.