Thermal Character of Geopolymers Synthesized from Class F Fly Ash Containing High Concentrations of Iron and α-Quartz
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– phase transition cause only minor variations in thermal expansion.
Document Type: Research Article
Affiliations: 1: Centre for Materials Research, Curtin University of Technology, Perth, WA 6845, Australia 2: Lucas Heights Research Labs, ANSTO, Institute of Materials Engineering, PMB1, Menai, NSW 2234, Australia
Publication date: January 1, 2010