Volume 7, Issue 1 p. 81-88

Thermal Character of Geopolymers Synthesized from Class F Fly Ash Containing High Concentrations of Iron and α-Quartz

William D. A. Rickard

William D. A. Rickard

Centre for Materials Research, Curtin University of Technology, Perth, WA 6845, Australia

This project is carried out under the auspice and with the financial support of the Centre for Sustainable Resource Processing (CSRP), which is established and supported under the Australian Government's Cooperative Research Centres Program.

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Arie van Riessen

Arie van Riessen

Centre for Materials Research, Curtin University of Technology, Perth, WA 6845, Australia

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Philip Walls

Philip Walls

Lucas Heights Research Labs, ANSTO, Institute of Materials Engineering, PMB1, Menai, NSW 2234, Australia

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First published: 04 January 2010
Citations: 119

Abstract

This article reports the thermal characteristics of geopolymers prepared with a class F fly ash containing 15 wt% iron oxide and 20 wt%α-quartz. The characterization techniques used included dilatometry, TGA, DTA, XRD, and SEM. Geopolymer specimens were prepared with nominal ratios of Si:Al=2.3 and Na:Al=0.85. Iron oxide in the fly ash precursor was found to play a critical role in the thermal expansion and morphology of geopolymers at temperatures >500°C. Volume changes of quartz on either side of the α–β phase transition cause only minor variations in thermal expansion.