摘要
NaY晶体的n(Na_2O)∶n(Al_2O_3)=1.0,但现有NaY合成工艺的起始凝胶的n(Na_2O)/n(Al_2O_3)均较高,导致大量原料中的Na_2O及相应量其他组分没有转化为产品,而是进入晶化母液被滤除,因此NaY生产企业期望采用更低n(Na_2O)∶n(Al_2O_3)的凝胶来提高NaY合成收率。对起始凝胶Na_2O与Al_2O_3物质的量比为3.84~4.64的水热合成NaY分子筛做了研究。结果表明,在100℃以下晶化时,n(Na_2O)∶n(Al_2O_3)=3.84的低碱度凝胶不能晶化出NaY分子筛;在100℃以上晶化时,n(Na_2O)∶n(Al_2O_3)=3.84的低碱度凝胶能够晶化出结晶度、硅铝比(Si O2与Al_2O_3物质的量比,下同)均较高且无杂晶的NaY。其最佳的晶化条件:晶化温度为110℃、晶化时间为30 h。并可重复制备出平均结晶度为95%、平均骨架硅铝比为5.93、典型粒径约为1μm的小晶粒NaY分子筛,原料平均转化率达68.2%。
The amount-of-substance ratio of Na_2O to Al_2O_3 of NaY zeolite crystal is 1.0.However the Na_2O/Al_2O_3 ratio of initial gel for manufacturing NaY is much higher in at present.This results in a large number of Na_2O and corresponding amounts of other components in raw materials not being converted into the products,but into the mother liquor.Consequently,the NaY manufacturers hope to increase utilization of raw materials by reducing n(Na_2O) ∶n(Al_2O_3) in initial gel to increase the conversion rate of raw materials.It was studied that the synthesis of the NaY zeolite by using the initial gel with lower n(Na_2O)∶n(Al_2O_3).The investigation range of the amount-of-substance ratio mentioned above was at 3.84~4.64.The experiment results showed that the initial gel with the lowest ratio,n(Na_2O)∶n(Al_2O_3)=3.84,could not be crystallized out NaY zeolite when the crystallizing temperature was below 100 ℃.However,when the crystallization temperature was above 100 ℃,the initial gel the lowest n(Na_2O)∶n(Al_2O_3) could produce NaY zeolite.The amount-of-substance ratio of silicon to alumina(Si O2 to Al_2O_3)is higher and no impurit crystal NaY.The optimized crystallization conditions were that the crystallizing temperature was110 ℃ and the crystallizing time was 30 h.NaY products from the repeated crystallizing experiments had satisfactory performance of which the average NaY crystallization degree was 95%,average amount-of-substance ratio of silicon to alumina was 5.93,and typical particle size was about 1 μm.The average conversion rate of raw materials reached 68.2%.
出处
《无机盐工业》
CAS
北大核心
2017年第11期66-70,共5页
Inorganic Chemicals Industry
基金
凉山州高新技术孵化项目(14GXJS0007)
四川省科技支撑计划(15GZ0360)
