Synthesis of pure zeolite X from palygorskite clay using a two-stage method

摘要

A natural mineral, palygorskite clay, was used to synthesize pure zeolite X via a two-stage method. The synthetic parameters, such as calcination, crystallization time, and SiO_2/Al_2O_3 molar ratio, were investigated. The results indicated that calcination enhanced the extraction of silica from palygorskite clay and was beneficial for the formation of zeolite X. Micro-sized pure zeolite X with the particle size of 1-4 ìm was obtained in the gel with the SiO_2Al_2O_3 molar ratio range of 1.93 to 3 after hydrothermal treatment at 80 °C for 5 h. The synthetic zeolite X showed high specific surface area (487 m~2/g) and low Si/Al ratio (1.17).