利用稻壳制备X型分子筛及性能研究

Preparation and Performances of X Molecular Sieve from Rice Husk

以稻壳为硅源,采用水热法成功合成出了X型分子筛,并对亚甲基蓝染料进行吸附。利用X射线衍射（XRD）、扫描电子显微镜（SEM）、紫外-可见光谱和钙离子交换能力对样品的性能进行表征与测试。研究结果表明,提纯后稻壳灰为无定型态,其主要成分Si O2含量高达98.96%;水热法合成X分子筛的最佳配比为n（Si O2）/n（Al2O3）=3.8、n（Na2O）/n（Si O2）=1.4、n（H2O）/n（Na2O）=40,最佳水热晶化温度为100℃,最佳晶化时间为8h。在此条件下,合成产物无杂相,晶形发育完好,结晶度高,钙离子交换能力高达310.3 mg·g-1。亚甲基蓝溶液初始p H值在11~12范围内,初始浓度小于30 mg·L-1,分子筛用量在0.10~0.25 g范围内时,产物对亚甲基蓝有较好的吸附效果。

X molecular sieve which adsorb methylene blue（ MB） was synthesized by hydrothermal method using rice husk as silicon source. The performances were characterized by X-ray diffraction（ XRD）,scanning electron microscope（ SEM）,Uv-vis spectrum and calcium ion exchange capacity. The results show that there is 98. 96% amorphous Si O2 in rice husk ash prepared by dipping treatment in acid solution. The optimal preparing proportions are Si O2/ Al2O3 molar ratio of 3. 8,Na2 O / Si O2 molar ratio of1. 4,and H2 O / Na2 O molar ratio of 40,the crystallization temperature of 100 ℃,the time of 8 h. Under the best conditions,the synthesizing molecular sieves have high purity,good crystal shape and high crystallinity,while its calcium ion exchange capacity is 310. 3 mg · g- 1. The product has a good adsorption effect on methylene blue when initial p H value is in the range of 11-12,the concentration of methylene blue is less than 30 mg·L- 1,and the molecular sieve dosage is in the range of 0. 10-0. 25 g.