Naslov
Fly Ash Waste-Based Geopolymers: Synthesis and Properties

Autori
Zelić, Jelica ; Jozić, Dražan ; Tibljaš, Darko

Vrsta, podvrsta i kategorija rada
Poglavlja u knjigama, znanstveni

Knjiga
Environmental Management ; Trends and Results

Urednik/ci
Koprivanac, Natalija ; Kušić, Hrvoje

Izdavač
Fakultet kemijskog inženjerstva i tehnologije Sveučilišta u Zagrebu

Grad
Zagreb

Godina
2007

Raspon stranica
233-240

ISBN
978-953-6470-34-1

Ključne riječi
Fly ash, geopolymers, synthesis, properties

Sažetak
Fly ash is the most important waste product of electricity production in coal-fired power station. It is being usually applied in cement and concrete industry, but the material has favourable properties for more valuable application, such as the conversion into the alkali – activated aluminosilicate materials, or "geopolymers"- a new environmentally friendly, sufficiency performing and cost effective an inorganic polymeric cementitious material. Comparing to Portland cement, the production of geopolymers consume less energy and almost no CO2 emission in the atmosphere. The present work reports the results of the preliminary study on the synthesis and properties of fly ash-based geopolymers prepared using the Croatian Class F fly ash (the Plomin 2 coal-fired Thermal Power Station, Plomin, Croatia) and sodium silicate solution (technical grade water glass. Fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy (SEM/EDS) and X-ray diffraction (XRD) techniques have been used to identify the new phases and to follow the progress of their formation. In addition, the effect of different curing conditions on the mechanical strength development of the alkali-activated fly ash mortars has also been studied. The results show that the glassy component of fly ash used reacted with water glass and the main reaction product formed in an alkali-activated geopolymers material was an amorphous alkaline aluminosilicate gel that induce a shift in the T – O (T = Si or Al) asymmetric stretching band towards lower wave number (1029 cm -1) related to ones in the original fly ash. It was found that mechanical strength of alkali-activated fly ash mortars are affected substantially by the duration of thermal activation and by the curing time, when the geopolymerisation reaction occurred with a longer reaction rate to produce high strength mortars.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

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