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Synthesis of zeolite A from coal fly ash by alkali fusion followed by hydrothermal treatment

알칼리 용융 및 수열 합성에 의한 석탄회로부터 제올라이트 A의 합성

  • Jeong, Ji-Baek (Department of Chemical and Biomolecular Engineering, Seoul National University of Science and Technology) ;
  • Choi, Ko-Yeol (Department of Chemical and Biomolecular Engineering, Seoul National University of Science and Technology)
  • 정지백 (서울과학기술대학교 화공생명공학과) ;
  • 최고열 (서울과학기술대학교 화공생명공학과)
  • Received : 2015.05.31
  • Accepted : 2015.06.05
  • Published : 2015.06.30

Abstract

Zeolite A was prepared from coal fly ash upon NaOH fusion treatment, followed by hydrothermal treatment. The effects of treatment conditions such as NaOH/ash ratio, fusion temperature, the amount of sodium aluminate added, hydrothermal treatment temperature and time on the type and the crystallinity of zeolites were investigated. The optimal NaOH/ash weight ratio and fusion temperature to produce high crystalline zeolite A were 1.2 and $550^{\circ}C$, respectively. The dissolution of $Si^{4+}$ and $Al^{3+}$ from the fused fly ash was not affected by stirring time. The type of synthetic zeolites was found to be dependent on the amount of sodium aluminate added. The low amount of sodium aluminate favored zeolite X, while a single phase zeolite A was produced by increasing the amount sodium aluminate. Zeolite A was transformed into hydroxysodalite with increasing hydrothermal treatment time and temperature. A high crystalline zeolite A could be obtained by decreasing the temperature increasing time up to the reaction temperature.

석탄회를 NaOH로 용융시킨 후 수열 처리에 의하여 제올라이트 A를 합성하였다. NaOH/석탄회의 비, 용융 온도, $NaAlO_2$의 첨가량, 수열 처리 온도 및 시간이 생성된 제올라이트의 종류와 결정도에 미치는 영향에 대하여 연구하였다. 결정도가 높은 제올라이트의 생성에 필요한 최적의 NaOH/석탄회의 중량비는 1.2, 최적의 용융 온도는 $550^{\circ}C$이었다. 용융된 석탄회로부터 $Si^{4+}$$Al^{3+}$의 용출은 교반 시간의 영향을 받지 않았다. 생성된 제올라이트의 형태는 첨가한 $NaAlO_2$의 영향을 받는 것으로 나타났다. 적은 양의 $NaAlO_2$를 첨가하면 제올라이트 X가 생성되나 $NaAlO_2$의 양이 증가하면 단일상의 제올라이트 A가 생성되었다. 수열처리 시간과 온도가 증가하면 제올라이트 A는 hydroxysodalite로 변화 하였다. 승온 속도를 낮춰 반응 온도까지의 도달시간을 증가시키면 결정도가 좋은 제올라이트 A를 얻을 수 있었다.

Keywords

References

  1. H. Tanaka and A. Fujii, Effect of Stirring on the Dissolution of Coal Fly Ash and Synthesis of Pure-form Na-A and Na-X Zeolites by Two-step Process, Advanced Powder Technol., 20, 473-479(2009). https://doi.org/10.1016/j.apt.2009.05.004
  2. K. Ojha, N. C. Pradhan, and A. N. Samanta, Zeolite from Fly Ash: Synthesis and Characterization, Bull. Mater. Sci., 27(6), 555-564(2004). https://doi.org/10.1007/BF02707285
  3. Y. Yaping, Z. Xiaoqiang, Q. Weilan, and W. Mingwen, Synthesis of Pure Zeolites from Supersaturated Silicon and Aluminum Alkali Extracts from Fused Coal Fly Ash, Fuel, 87, 1880-1886(2008). https://doi.org/10.1016/j.fuel.2007.12.002
  4. H. Tanaka, H. Eguchi, S. Fujimoto, and R. Hino, Two-step Process for Synthesis of a Single Phase Na-A Zeolite from Coal Fly Ash by Dialysis, Fuel, 85, 1329-1334 (2006). https://doi.org/10.1016/j.fuel.2005.12.022
  5. P. Thuadaij and A. Nuntiya, Effect of the $SiO_2/Al_2O_3$ Ratio on the Synthesis of Na-X Zeoliet from Mae Moh Fly Ash, Science Asia, 38, 295-300(2012). https://doi.org/10.2306/scienceasia1513-1874.2012.38.295
  6. T. T. Walek, F. Saito, and Q. Zhang, The Effect of Low Solid/liquid Ratio on Hydrothermal Synthesis of Zeolites from Fly Ash, Fuel, 87, 3194-3199(2008). https://doi.org/10.1016/j.fuel.2008.06.006
  7. C. Belviso, F. Cavalcante, F. J. Huertas, A. Lettino, P. Ragone, and S. Fiore, The Crystallization of Zeolite (X- and A type) from Fly Ash at $25^{\circ}C$ in Artificial Sea Water, Micropor. and Mesopor. Materials, 162, 115-121(2012). https://doi.org/10.1016/j.micromeso.2012.06.028
  8. H. Tanaka, Y. Sakai, and R. Hino, Formation of Na-A and -X Zeolites from waste solutions in Conversion of Coal Fly Ash to Zeolites, Materials Research Bulletin, 37, 1873-1884(2002). https://doi.org/10.1016/S0025-5408(02)00861-9
  9. R. Sommerville, R. Blissett, N. Rowson, and S. Blackburn, International J. Mineral Processing, 124, 20-25(2013). https://doi.org/10.1016/j.minpro.2013.07.005
  10. V. K. Jha, M. Nagae, M. Matsuda, and M. Miyake, Zeolite Formation from Coal Fly Ash and Heavy Metal Ion Removal Characteristics of thus-obtained Zeolite X in Multi-metal Systems, J. Environmental Management, 90, 2507-2514(2009). https://doi.org/10.1016/j.jenvman.2009.01.009
  11. N. M. Musyoka, L. F. Petrik, E. Hums, H. Baser, and W. Schwieger, In Situ Ultrasonic Diagnostic of Zeolite X Crystallization wit Novel(hierarchical) Morphology from Coal Fly Ash, Ultrasonics, 54, 537-543(2014). https://doi.org/10.1016/j.ultras.2013.08.005
  12. C. Belviso, F. Cavalcante, and S. Fiore, Synthesis of Zeolite from Italian Coal Fly Ash: Differences in Crystallization Temperature Using Seawater Instead of Distilled Water, Waste Management, 30, 839-847(2010). https://doi.org/10.1016/j.wasman.2009.11.015
  13. M. R. El-Naggar, A. M. El-Kamash, M. I. El-Dessouky, and A. K. Ghonaim, Two-step method for Preparation of NaA-X Zeolite Blend from Fly Ash for Removal of Cesium Ions, J. Hazardous Material, 154, 963-972(2008). https://doi.org/10.1016/j.jhazmat.2007.10.115
  14. H. Kazemian, Z. Naghdali, T. G. Kashani, and F. Farhadi, Conversion of High Silicon Fly Ash to Na-P1 Zeolite: Alkaline Fusion Followed by Hydrothermal Treatment, Advanced Powder Technol., 21, 279-283(2010). https://doi.org/10.1016/j.apt.2009.12.005
  15. J. D. Jee and K. Y. Choi, Synthesis of Zeolite A from Coal Fly Ash, Appl. Chem. Eng., 22(2), 214-218(2011).
  16. M. Inada, H. Tsujimoto, Y. Eguchi, N. Enomoto, and J. Hojo, Microwave-assited Zeolite Synthesis from Coal Fly Ash in Hydrothermal Process, Fuel, 84, 1482-1486 (2005).
  17. N. Sigemoto, H. Hayashi, and K. Miyaura, Selective Formation of Na-X Zeolite from Coal Fly Ash by Fusion with Sodium Hydroxide prior to Hydrothermal Reaction, J. Material Sci., 28, 4781-4786 (1993). https://doi.org/10.1007/BF00414272
  18. X. Querol, A. Alastuey, A. Lopez-Soler, F. Plana, J. M. Andres, R. Juan, P. Ferrer, and C. R. Ruiz, A Fast Method for Recycling Fly Ash: Microwave-assisted Zeolite Synthesis, Environ. Sci. Thechnol., 31, 2527-2533(1997). https://doi.org/10.1021/es960937t