Thermal degradation kinetics of sepiolite

Sarikaya Y., ÖNAL M., Pekdemir A. D.

CLAY MINERALS, cilt.55, sa.1, ss.96-100, 2020 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 55 Sayı: 1
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1180/clm.2020.8
  • Dergi Adı: CLAY MINERALS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Agricultural & Environmental Science Database, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Chemical Abstracts Core, Communication Abstracts, Compendex, Geobase, INSPEC, Metadex, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.96-100
  • Anahtar Kelimeler: decomposition, degradation, kinetics, sepiolite, thermal analysis, ACTIVATED SEPIOLITE, TREATED SEPIOLITE, ESKISEHIR, BEHAVIOR, DEHYDROXYLATION, DEHYDRATION, MECHANISM, WATER, JUICE
  • Ankara Üniversitesi Adresli: Evet

Özet

The kinetic parameters of the thermal degradation of sepiolite were evaluated with a new method based on thermal analysis data. Thermogravimetric/differential thermal analysis curves were recorded for the natural and preheated sepiolite samples in the temperature range 25-800 degrees C for 4 h. The temperature-dependent height of the exothermic heat flow peak for the thermal decomposition of sepiolite located at similar to 850 degrees C on the differential thermal analysis curve was taken as a kinetic variable for the thermal degradation. A thermal change coefficient was defined depending on this variable because this coefficient fit to the Arrhenius equation was assumed as a rate constant for the thermal degradation. The Arrhenius plot showed that the degradation occurs in three steps. Two of these are due to stepwise dehydration and the third originated from dehydroxylation of sepiolite. Three activation energies were obtained that increase with the increasing temperature interval of the steps.