酸溶粉煤灰残渣制备4A分子筛

Preparation of 4A Molecular Sieve from Acid Insoluble Ash Residue

以酸溶粉煤灰提取氯化铁后的残渣为原料,采用碱熔-水热法制备4A分子筛,系统研究了反应体系碱度、陈化时间、晶化时间及晶化温度对4A分子筛钙离子交换能力和物相组成的影响,所得产品通过X射线衍射、透射电镜、激光粒度分析仪等进行分析与表征。研究结果表明,在碱度7.5、陈化24h、晶化温度90℃、晶化4h的条件下,可获得结晶度好、平均粒径1.503μm、平均孔径0.4nm,钙离子交换能力305.54mg/g的4A分子筛。

Acid insoluble ash residue was obtained from fly ash acid-dissolving extracting ferric chloride.4A molecular sieve was prepared with the acid insoluble ash by alkaline-hydrothermal method.The influences of several important parameters on calcium exchange ability and phase composition of 4A molecular sieve,such as the concentration of alkali solution,aging time,crystallization time and temperature,were studied.X-ray diffraction,TEM and laser particle size analyzer were used to investigate the structure and the crystal type of 4A molecular sieve.The results showed that 4A molecular sieve can be obtained at the alkalinity of 7.5,the aging time of 24 h,the crystallization temperature of 90 ℃,the crystallization time of 4 h.The 4A molecular sieve is better crystallinity,average diameter 1.503 μm,average microporous pore size distribution 0.4 nm and calcium exchange ability 305.54 mg/g.