In Situ Synthesis of NaY Zeolite with Coal—Based Kaolin

NaY zeolites were in-situ synthesized from coal-based kaolin via the hydrothermal method.The effects of various factors on the structure of the samples were extensively investigated. The sampleswere characterized by N2 adsorption, XRD, IR and DTG-DTA methods, and the results show that thecrystallization temperature and amount of added water play an important role in the formation of the zeo-lite structure. The 4A and P zeolites are the competitive phase present in the resulting product. However,NaY zeolites with a higher relative crystallinity, excluding impure crystals and the well hydrothermal sta-bility, can be synthesized from coal-based kaolin. These zeolites possess a larger surface area and a narrowpore size distribution, and this means that optimization of this process might result in a commercial routeto synthesize NaY zeolites from coal-based kaolin.