Abstract: Low-silica X zeolite (LSX) was synthesized by two-step hydrothermal process with low temperature aging and high temperature crystallization period. The effects of aging temperature, aging time, crystallization temperature and crystallization time were investigated, then the optimal synthesis conditions were obtained. The synthesized sample at optimized conditions was characterized by X-ray diffraction, chemical analysis and N_2 adsorption and desorption. The results showed that the LSX with high puring had low SiO_2/Al_2O_3 ratio and high purity. Its specific surface area reached 503 m~2·g~(-1) and the micropore size distribution curve spread in a narrow range.

Key words: two-step hydrothermal treatment%low-silica X zeolite（LSX）%low temperature aging%high temperature crystallization