Synthesis and crystallization of zeolite t by microwave heating

The crystallization of Zeolite T under microwave-heating system was studied. The effects of synthesis parameters such as synthesis time, gel composition, reaction pressure and template on crystallization were investigated. The results show that the crystalline zeolite T is obtained in 20-25 h without template under the microwave hydrothermal treatment in contrast to more than 120 h by conventional heating method. The crystallization fields of the metastable phase of zeolite T is narrowed due to the favored formation of the stable phase of phillipsite by the fast heating of microwave irradiation. The formation fields of zeolite T without template under microwave hydrothermal synthesis are: 20≤n _sio2/n _M2o/n _sio2 ≤22 and 0.31 ≤n _M2o/n _sio2 ≤0.33(where M ₂O=Na ₂O+K ₂O,n _Na/n _k=3 and n _Na/n _k=3 and n _H2O =11.70) at 100 °C. The addition of template(tetramethylammonium(TMA) cation) will broaden the crystallization field of zeolite T and further reduce the synthesis time in both of the microwave-heating system and the conventional-heating system.