New Method and Effect Verification for Synthesizing Sodalite from Fly Ash Using Solvent-Free Method
Due to its high silicon and aluminum content,low silicon and aluminum ratio,fly ash is often used to synthesize low silicon pure phase sodalite.In order to improve the high-value utilization of fly ash,sodalite was synthesized from fly ash using solvent-free method.The effects of ash-alkali ratio,crystallization time and crystallization temperature on sodalite phase formation,microstructure and crystallinity were studied.The results show that crystaline pristine sodalite is prepared from fly ash with ash-alkali ratio of 1∶0.8(mass ratio),crystallization time of 16 h and crystallization temperature of 160 ℃.The ash-alkali ratio has a significant effect on relative crystallinity.The synthesized sodalite has microporous and mesoporous composite pore structure.The N2 adsorption-desorption isotherm of sodalite isotherm reveals a typical Ⅳisotherm with a type Ⅲ hysteresis loop.Sodalite has high aluminum content,and has good thermal stability.Compared with the hydrothermal method for synthesizing sodalite,this experimental method utilizes fly ash with high efficiency,and provides a new way for the utilization of fly ash.