以粉煤灰为原料两步法合成亚微米NaA型沸石  

SYNTHESIS OF SUBMICRON NaA ZEOLITE FROM FLY ASH USING A TWO-STAGE METHOD

作　　者：王春峰[1] 李健生[1] 韩卫清[1] 王连军[1] 孙秀云[1] 

机构地区：[1]南京理工大学化工学院,江苏210094

出　　处：《硅酸盐学报》2008年第11期1638-1643,共6页Journal of The Chinese Ceramic Society

基　　金：高等学校博士学科点专项科研基金(20060288008);江苏省自然科学基金(BK2006205)资助项目

摘　　要：以粉煤灰为原料,采用两步法合成了亚微米NaA型沸石(Na12[Al12Si12O48].27H2O)。研究了晶化时间和NaOH溶液浓度对合成亚微米NaA型沸石的纯度、结晶度和粒度的影响。结果表明:晶化时间将影响NaA型沸石的纯度和结晶度;NaOH溶液浓度主要影响产物的粒径大小和粒度分布范围。通过优化合成条件,在5mol/L和6.67mol/LNaOH溶液浓度的条件下,由粉煤灰制备的硅铝凝胶,在100℃分别晶化4h和3h可合成骨架结构完好,结晶度高的亚微米NaA型沸石。合成的亚微米NaA型沸石的平均粒径分别为450nm和250nm,粒径分布范围(sizespan,SP)分别为3.84和2.44。合成产物的NH4+和Cu2+离子交换容量随着晶粒的减小而显著增加。Submicron NaA type zeolite （Na12[Al12Si12O48]·27H2O） was synthesized from fly ash using a two-stage method. The effect of crystallization time and concentration of NaOH solution on the purity, crystallinity and particle size of submicron NaA type zeolite synthesized from fly ash was investigated. The results show the crystallization time mainly affects the purity and crystallinity of NaA type zeolite. The particle size distribution of NaA type zeolite depends mainly on the concentration of the NaOH solution. By optimizing the synthesis conditions, pure submicron NaA type zeolite with a single phase and high crystallinity can be synthesized during the hydrothermal treatment of fly ash prepared in the initial gel after 4 h and 3 h in the conditions of 5 mol/L and 6.67 mol/L NaOH solutions, respectively. The average crystal size of submicron NaA type zeolite are 450nm and 250nm, and the size spans are 3.84 and 2.44, respectively. The NH4＋ and Cu2＋ ion exchange capacity of NaA type zeolite increase markedly with a decrease of the crystal size.

关 键 词：粉煤灰 两步法 亚微米 沸石 硅铝凝胶 

分 类 号：X705[环境科学与工程—环境工程]