KALSİT İLAVELİ JEOPOLİMER MALZEMELERİ SİNTERLEMENİN GÖZENEKLİLİĞE ETKİLERİ - SINTERING OF CALCITE ADDED GEOPOLYMERIC MATERIALS EFFECTS ON POROSITY

Abstract

KALSİT İLAVELİ JEOPOLİMER MALZEMELERİ SİNTERLEMENİN GÖZENEKLİLİĞE ETKİLERİ

Bu çalışmada, uçucu kül esaslı jeopolimerlere kalsit ilavesiyle elde edilen malzemelerin farklı sıcaklıklarda sinterlenmesi ile gözenekliliğe etkileri araştırılmıştır. Bu amaçla, uçucu kül (100U) ve %20 kalsit ilaveli uçucu kül(80U20K) ile jeopolimerik kompozisyonlar hazırlanmıştır. Bu kompozisyonların sodyum hidroksit (12M), sodyum silikat çözeltileriyle aktive edilmesi ve daha sonra numunelerin 80°C’de 24 saat kürlenmesi ile jeopolimerik yapılar elde edilmiştir. Elde edilen jeopolimerik numuneler, 500, 700 ve 900°C’de 30 dakika süreyle sinterlenmiştir. Jeopolimer malzemelerde kalsitin sinterleme davranışlarına etkisi termal analiz (DSC) ile belirlenmiştir. Üretilen malzemeler faz analizi (XRD), gözenek boyutu (civa porozimetre), görünür yoğunluk, açık gözeneklilik ve su emme analizleri ile karakterize edilmiştir. Sinterleme sıcaklığının artması ile malzemelerde açık gözeneklilik değerlerinde azalma meydana gelmiştir. Jeopolimer malzemelerin 900°C’de sinterlenmesi ile nefelin gibi camsı fazların oluşumu, 100U numunesinde açık gözeneklilik değerini %29,78’den %12,30’a düşürürken, 80U20K numunesinde ise %39,23’den % 32,65’e düşüş

 

SINTERING OF CALCITE ADDED GEOPOLYMERIC MATERIALS EFFECTS ON POROSITY

In this study, the effects of sintering at different temperatures on porosity of materials produced by addition of calcite in fly ash based geopolymers are investigated. For this purpose, geopolymeric compositions are prepared by fly ash (100U) and 20% calcite added fly ash (80U20K). Activating of these compositions with sodium hydroxide(12M) and sodium silicate solutions and then curing of the samples at 80 °C for 24 hours geopolymeric structures are obtained. The produced geopolymeric samples are sintered at 500°C, 700°C, and 900°C temperatures for 30 minutes. The temperature increase rate is 5°C/min. The effects of calcite in geopolymeric materials on sintering behaviour are determined by thermal analysis (DSC). The produced materials are characterized by phase analysis (XRD), porous size (mercury porosimeter), apparent density, open porosity, and water absorption analysis. As the sintering temperature is increased, open porosity values in materials decrease. Emergence of glassy phases such as nepheline by sintering the geopolymeric materials at 900°C, decrease 100U sample open porosity value from %29.78 to 12.30%, 80U20K sample value from %39.23 to 32.65%. Calcite addition to the materials provides porosity in the samples at 900°C, the temperature at which glassy phases emerge.

 

 

Keywords

• Uçucu kül, Kalsit, Jeopolimer, Sinterleme, Gözeneklilik

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Abstract

In this study, the effects of sintering at different temperatures on porosity of materials produced by addition of calcite in fly ash based geopolymers are investigated. For this purpose, geopolymeric compositions are prepared by fly ash (100U) and 20% calcite added fly ash (80U20K). Activating of these compositions with sodium hydroxide(12M) and sodium silicate solutions and then curing of the samples at 80 °C for 24 hours geopolymeric structures are obtained. The produced geopolymeric samples are sintered at 500°C, 700°C, and 900°C temperatures for 30 minutes. The temperature increase rate is 5°C/min. The effects of calcite in geopolymeric materials on sintering behaviour are determined by thermal analysis (DSC). The produced materials are characterized by phase analysis (XRD), porous size (mercury porosimeter), apparent density, open porosity, and water absorption analysis. As the sintering temperature is increased, open porosity values in materials decrease. Emergence of glassy phases such as nepheline by sintering the geopolymeric materials at 900°C, decrease 100U sample open porosity value from %29.78 to 12.30%, 80U20K sample value from %39.23 to 32.65%. Calcite addition to the materials provides porosity in the samples at 900°C, the temperature at which glassy phases emerge

Keywords

• Fly ash, calcite, geopolymer, sintering, porosity

References

1. Davidovits J. “Geopolymers – inorganic polymeric new materials”. J Therm Anal 37, 1633– 1656, (1991).
2. [] Duxson P, Provis JL, Lukey G. C, van Deventer J.S.J. “The role of inorganic polymer technology in the development of ‘Green concrete’”. Cement Concrete Research, 37(12), 1590–1597, (2007)
3. [] Palomo A, Grutzeck M.W., Blanco M.T., “Alkali-activated fly ashes, a cement for the future”, Cement and Concrete Research, 29:1323– 1329, (1999).
4. [] Li Z., Zhang Y., Zhou X., “Short Fiber Reinforced Geopolymer Composites Manufactured by Extrusion”, Journal of Materials in Civil Engineering,17,624-631, (2005).
5. Swanepoel J.C., Strydom C.A., “Utilisation of fly ash in a geopolymeric material”, Applied Geochemistry,17, 1143-1148, (2002).
6. Yip C. K.,. Provis J. L., Lukey G. C., van Deventer J.S.J., “Carbonate mineral addition to metakaolin-based geopolymers”, Cement & Concrete Composites 30, 979–985, (2008).
7. Abdulkareem O. A., Mustafa Al Bakri A. M., Kamarudin H., Khairul Nizar I., Saif, A. A.," Effects of elevated temperatures on the thermal behavior and mechanical performance of fly ash geopolymer paste, mortar and lightweight concrete", Constr. Build. Mater. 50, 377–387 (2014).
8. Bakharev T., "Thermal behaviour of geopolymers prepared using class F fly ash and elevated temperature curing", Cem. Concr. Res. 36, 1134–1147 (2006).

9. Duxson P., Lukey G. C., van Deventer J. S. J.,"The thermal evolution of metakaolin geopolymers: Part 2 – Phase stability and structural development", J. Non. Cryst. Solids 353, 2186–2200 (2007).
10. Duxson P., Lukey G. C., van Deventer J. S. J., geopolymers: Part 1 – Physical evolution", J. Non. Cryst. Solids 352, 5541–5555 (2006).
11. Elimbi A., Tchakoute H. K., Kondoh M., Dika characteristics of fired geopolymers produced from local Cameroonian metakaolin", Ceram. Int. 40, 4515–4520 (2014). behavior and Şan O., Özgür C., Uysal K., Koç M.,
12. Ergüler T., İmaretli A., Alabalık Tesisi Suyunun Kapiler Seramik Filtreler İle Süzülebilirliğinin Araştırılması, Dumlupınar Üniversitesi, Fen Bilimleri Enstitüsü, Sayı 25, (2011).
13. Hu L., Wang C., Effect Of Sintering Temperature on Compressive Strength of Porous Yttria-Stabilized Zirconia Ceramics, Ceramics International 36, 1697–1701, (2010)
14. Sun Z., Bai C., Zheng S., Yang X., Frost R. L.,A Comparative Study of Different Porous Amorphous Silica Minerals Supported TiO2 Catalysts, Applied Catalysis 458, 103–110, (2013)
15. IsobeT., Shimizu M., Matsushita S., Nakajima A., “Preparation and gas permeability of the surface-modified porous Al2O3 ceramic filter for CO gas separation”, Journal of Asian Ceramic Societies, 1, 65-70,(2013).
16. Şan O., “Microstructural characterization of capillary filter produced from a high silica- containing glaze”, Materials Letters, 57, 2189- 2192, (2003).
17. Kim Y. A., Choi J. H.,. Chiang J. S. K, Amal R., “Preparation of high porous Pt–V2O5– WO3/TiO2/SiC filter for simultaneous removal of NO and particulates”, Powder Technology, 180, 79- 8, (2008). Geliş Tarihi:24.01.2014 Kabul Tarihi: 07.03.2014