WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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Department: search.filters.department.İzmir Institute of Technology. Chemical EngineeringSubject: search.filters.subject.Particle size

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  • Article
    Kinetics of Proton Transfer in the Zeolitic Tuff
    (Central European Science Journals, 2009) Çakıcıoğlu Özkan, Seher Fehime; Özkan, Seher Fehime; Özkan, Seher Fehime; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The kinetics of a proton transfer into dilute acid solutions containing natural zeolitic tuff was studied by following the pH evolution of the liquid phase. Four different solutions with tuff contents of 9, 3, 1 and 0.5 (% wt) and three different particle size fractions (≤ 2000 μm) were studied. The proton concentration of the solution was decreased by increasing the zeolite amount and decreasing the particle size fraction. The proton transfer reaction was analyzed with chemical reactions and diffusion model equations. Analysis shows that the adsorption and/or ion exchange are possible mechanisms and are expressed by a second order reaction model.
  • Article
    Citation - WoS: 26
    Citation - Scopus: 28
    Thermal Stability of Ag-Exchanged Clinoptilolite Rich Mineral
    (Springer Verlag, 2008) Akdeniz, Yelda; Ülkü, Semra; Ülkü, Semra; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Thermal stability of clinoptilolite rich mineral from Western Anatolia, Turkey and its Ag-exchange forms was investigated. Parent mineral of different sizes were heated up to 1000°C with heating rate of 2 and 10°C min -1 using differential thermal analyzer (DTA) and thermogravimetric analyzer (TG). Ag exchange was conducted both in conventional constant temperature waterbath and microwave at 40, 60 and 80°C. The exchanged minerals were then characteized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), DTA and TG. The particle size and heating rate do not have significant effect on the thermal behavior of the parent mineral and no structural changes were observed with Ag exchange, only decomposition temperature was lowered. It was finally concluded that, Ag-exchanged clinoptilolite rich minerals were less thermally stable compared to parent mineral that does not affect their use for possible applications.