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利用粉煤灰合成沸石分子筛的方法评述 总被引:4,自引:2,他引:2
本文综述了利用粉煤灰合成沸石的方法及其最新进展,对不同合成方法的优缺点进行了比较,并探讨了当前研究中存在的问题及将来的发展方向. 相似文献
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以粉煤灰为原料采用微波水热合成法制备沸石,将其用于废水处理中,考察了粉煤灰合成沸石对氨氮、磷、Fe2+、Mn2+、Cu2+的去除效果.实验结果表明,与粉煤灰相比,粉煤灰合成沸石具有更高的氨氮、磷去除率;在吸附去除废水中的Fe2+、Mn2+、Cu2+时,合成沸石比天然沸石更有效. 相似文献
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粉煤灰合成沸石吸附硫酸盐条件优化试验研究 总被引:2,自引:0,他引:2
以粉煤灰为原料合成了沸石。通过单因素试验及正交试验,探讨了沸石的合成条件及合成沸石吸附处理硫酸盐水质时的最优条件组合。结果表明:粉煤灰合成沸石制备条件为:溶解NaOH与粉煤灰质量比为1:1、熔融温度和时间分别为400℃和1h,水热温度和时间分别为60℃和4h。影响合成沸石去除SO4^2-离子的因素主次及水平依次为:沸石粒径0.2mm,搅拌时间45min,沸石投加量10g·L^-1,溶液pH。 相似文献
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Natlia Moreno Xavier Querol Angel Lpez‐Soler Jos Manuel Andres Maria Janssen Henk Nugteren Mark Towler Kenneth Stanton 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(9):1009-1018
Zeolitic material is obtained from fly ash both by direct conversion of the ash or from SiO2 extracts obtained from fly ash. This study focuses on determining the suitability of a fly ash for SiO2 extraction and for zeolite synthesis by direct conversion. The SiO2 extraction experiments from different fly ashes show that the main parameters governing the SiO2 extraction are: (a) a high bulk SiO2 content (>52%, for obtaining an extraction yield of 100 g SiO2 kg?1) in the starting fly ash, (b) a high proportion (>55%) of the bulk SiO2 present in the degradable glass matrix and the highly soluble opaline fraction, and (c) a high bulk SiO2/Al2O3 ratio (>2.0) of the fly ash. The results from experiments of zeolite synthesis by direct conversion demonstrate that the most important criteria for the selection of a fly ash for this process are: (a) a high content of Al2O3 and SiO2(>65%) (b) a high glass content (>63%) and (c) relatively low SiO2/Al2O3 ratio (<2.0). Multivariate analysis confirms the importance of the above‐mentioned variables and shows some additional variables that have influence on ash behaviour under alkaline conditions. It quantifies the use of those variables for determining the suitability of ashes for SiO2 extraction and zeolite synthesis and is able to distinguish between the two. Copyright © 2004 Society of Chemical Industry 相似文献
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Yanan Zhang Wei Kang Hongjing Han Haiying Wang Yanguang Chen Xuzhong Gong Changxiu Zhai Hua Song 《Journal of the American Ceramic Society》2019,102(12):7665-7677
Here, a novel approach has been proposed to synthesize NaP zeolite adsorbents doped with transition metals (M-NaP) using the Na2SiO3 and NaAlO2 compounds extracted from fly ash via activation and stage treatment. The preparation process of M-NaP employed the in-situ synthesis in combination with organic complexation method. The effects of the addition amounts and valence state of transition metals on the zeolite products were investigated. The crystalline phase, morphology, and particle size of M-NaP were characterized using X-ray diffractometry (XRD), Scanning electron microscopy (SEM), and Laser particle size analyzer (PSD). The doping process was investigated using X-ray photoelectron spectroscopy (XPS) and Materials Studio. The adsorption performance of M-NaP was tested by the adsorption of Zn2+. The optimal molar ratio of n(Al2O3)/n(M) was identified as 8:1 for Co–NaP, Ni–NaP, and Fe–NaP, compared with 6:1 for Ti–NaP. The influence of transition metals on adsorption was: Co–NaP > Ni–NaP > Ti–NaP > Fe-NaP. Due to largest surface area of Co–NaP (162.5 m2/g, five times than that of NaP-RAW), the maximum removal rate of Zn2+ was above 99.50% at 25°C. The existence state of transition metals in M-NaP primarily included: isomorphous substitution and balance of the skeletal charge, with the latter in majority. The simulation of Materials Studio indicates that Si at T4 was first substituted and then, Si at T3 opposite T4 was replaced when the replacement of Si in different sites occurred. 相似文献
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利用粉煤灰合成沸石的方法很多,其中水热法合成沸石因操作简单、能耗低被认为是将粉煤灰基沸石商业化最可行的手段。采用水热法将国内外不同产地的几种粉煤灰合成沸石,并通过X射线衍射(XRD)、X射线荧光光谱(XRF)、热重分析(TG-DTA)、扫描电镜(SEM)等手段对合成的沸石产品进行表征,并在同一水热合成参数下考察不同粉煤灰合成沸石在品质上的差异。XRD谱图表明,原料中有80%~90%的成分转化为沸石,且沸石主要结晶类型为Na-P1型,也有少量的A型;XRF分析表明,3种粉煤灰基沸石硅铝物质的量比分别为1.61、1.35、1.45,符合XRD谱图的分析结论;TG-DTA表明,合成沸石在500 ℃以上几乎没有质量损失,具有良好的热稳定性;由SEM照片可见,合成的沸石为非球形,表面的纹理可增加沸石比表面积,结晶状态好。整个实验过程简单、成本低、合成沸石样品品质较高,由此可见通过水热法将粉煤灰合成沸石产品具有巨大的商业化潜力。 相似文献