The application of differential thermal analysis to the study of isothermal and non-isothermal crystallization kinetics of coal fly ash based glasses

Erol M. M., KUCUKBAYRAK S., ERSOY-MERICBOYU A.

Journal of Non-Crystalline Solids, cilt.355, sa.9, ss.569-576, 2009 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 355 Sayı: 9
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1016/j.jnoncrysol.2009.01.023
  • Dergi Adı: Journal of Non-Crystalline Solids
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.569-576
  • Anahtar Kelimeler: Crystallization, Crystal growth, Glass ceramics, Glasses, CRYSTAL-GROWTH, URBAN INCINERATION, INDUSTRIAL-WASTES, INORGANIC WASTES, NUCLEATION, CERAMICS
  • İstanbul Teknik Üniversitesi Adresli: Evet

Özet

The crystallization kinetics of glasses obtained from coal fly ash was investigated by both isothermal and non-isothermal methods using differential thermal analysis (DTA) data. In DTA experiments, glass samples having coarse (800-1000 μm) and fine (<180 μm) particle sizes were used and the results were compared. The Avrami exponent (n) was calculated by means of Johnson-Mehl-Avrami (JMA) and Ozawa equations. Calculated kinetic parameters indicated that the appropriate crystallization mechanisms were bulk and surface crystallization for coarse and fine particles, respectively. Isothermal and non-isothermal DTA experiments showed that the crystallization activation energies of coarse glasses are changed in the range of 444-578 kJ/mol, while the crystallization activation energies of fine glasses are changed in the range of 610-662 kJ/mol. It was found that crystallization activation energies of fine glasses are higher than those of the coarse glasses. Results showed that isothermal and non-isothermal crystallization kinetics of glasses produced from coal fly ash is in agreement within the experimental error. © 2009 Elsevier B.V. All rights reserved.