The effect of various treatment conditions on natural zeolites: Ion exchange, acidic, thermal and steam treatments


Autoria(s): Ates, Ayten; Hardacre, Christopher
Data(s)

15/04/2012

Resumo

Two different natural zeolites having different phase compositions were obtained from different regions of Turkey and modified by ion-exchange (0.5 M NH4NO3) and acid leaching using 1 M HCl. The natural and modified samples were treated at low temperature (LT), high temperature (HT) and steam (ST) conditions and characterised by XRF, XRD, BET, FTIR, DR-UV-Vis, NH3-TPD and TGA. Ion-exchange with NH4+ of natural zeolites results in the exchange of the Na+ and Ca2+ cations and the partial exchange of the Fe3+ and Mg2+ cations. However, steam and acidic treatments cause significant dealumination and decationisation, as well as loss of crystalline, sintering of phases and the formation of amorphous material. The presence of mordenite and quartz phases in the natural zeolites increases the stability towards acid treatment, whereas the structure of clinoptilolite-rich zeolites is mostly maintained after high temperature and steam treatments. The natural and modified zeolites treated at high temperature and in steam were found to be less stable compared with synthetic zeolites, resulting in a loss of crystallinity, a decrease in the surface area and pore volume, a decrease in the surface acidity as well as dealumination, and decationisation. (C) 2012 Elsevier Inc. All rights reserved.

Identificador

http://pure.qub.ac.uk/portal/en/publications/the-effect-of-various-treatment-conditions-on-natural-zeolites-ion-exchange-acidic-thermal-and-steam-treatments(5e675a51-185e-44fa-9fae-41b99da5dfe5).html

http://dx.doi.org/10.1016/j.jcis.2012.01.017

Idioma(s)

eng

Direitos

info:eu-repo/semantics/restrictedAccess

Fonte

Ates , A & Hardacre , C 2012 , ' The effect of various treatment conditions on natural zeolites: Ion exchange, acidic, thermal and steam treatments ' Journal of Colloid and Interface Science , vol 372 , no. 1 , pp. 130-140 . DOI: 10.1016/j.jcis.2012.01.017

Palavras-Chave #/dk/atira/pure/subjectarea/asjc/2500/2508 #Surfaces, Coatings and Films #/dk/atira/pure/subjectarea/asjc/2500/2504 #Electronic, Optical and Magnetic Materials #/dk/atira/pure/subjectarea/asjc/2500/2502 #Biomaterials #/dk/atira/pure/subjectarea/asjc/1500/1505 #Colloid and Surface Chemistry
Tipo

article