黄陵煤矸石制备4A分子筛的研究

Preparation of 4A Molecular Sieve Using Huangling Coal Gangue

黄陵煤矸石的灰成分以SiO2、Al2O3为主,这些组分正是合成分子筛的原料。将煤矸石经过煅烧活化、酸浸除铁、碱熔预处理后,采用水热合成的方法制备4A分子筛。通过正交试验考察了n（Na2O）∶n（SiO2）、n（H2O）∶n（Na2O）、老化时间、晶化温度、晶化时间5个因素对分子筛钙离子交换性能的影响,实验结果表明：n（Na2O）∶n（SiO2）是对4A沸石钙离子交换量影响最大的因素,其次是晶化温度,最小的为老化时间;且在n（Na2O）∶n（SiO2）为1.3,n（H2O）∶n（Na2O）为45,老化时间8 h,晶化时间4 h,晶化温度85℃下制备所得4A分子筛的钙离子交换量达到296.84 mg CaCO3/g干沸石。自制分子筛的XRD及SEM检测分析表明,最优条件下制备出的4A分子筛晶型完整,轮廓清晰,呈立方体,颗粒大小均匀,在1-2μm左右。

The chemical components of Huangling coal slime were mainly SiO2 and Al2O3, these components were just the materials to prepare molecular sieve. After the coal slime was treated by calcination, acid leaching for removing iron, and alkali fusion, the method of hydrothermal synthesis was adopted to prepare 4A molecular sieve. The effect of n （Na2O） ： n （SiO2 ） （mole ratio）, n （H2O） ： n （Na2O）, aging time, crystallization temperature, and crystallization time on the Ca^2＋ exchanging capacity properties of 4A molecular sieve was studied by orthogonal test method. The results showed that n （Na2O）： n （SiO2） was the maximal influence factor on the Ca^2＋ exchange capacity of 4A zeolite, followed by the crystallization temperature and the minimum was the aging time, and when the n （Na2O） ： n （ SiO2 ） was 1.3, the n （ H2O） ： n （ Na2O） was 45, the aging time was 8 h, the crystallization time was 4 h, the crystallization temperature was 85 ℃, the Ca^2＋ exchanging capacity of 4A molecular sieve reached 296.84 mg CaCO3/g dry zeolite. The XRD and SEM analyses showed that the self-prepared 4A molecular sieve had complete crystal shape, the outline was clear and cubic, and the particle size was uniform and about 1 -2 μm.