Journal Published Online: 01 December 2003
Volume 25, Issue 2

Role of Fly Ash and Aluminum Addition on Ettringite Formation in Lime-Remediated Mine Tailings



In this study, experiments were performed to evaluate the formation of ettringite in mine tailings samples treated with lime, fly ash type “C,” and aluminum. The success of the treated samples was evaluated based on results of X-ray diffraction and scanning electron microscopy. Using lime and fly ash, the preliminary investigation showed that addition of 5 % lime and 10 % fly ash constitutes the threshold of the treatment agents needed to form ettringite. However, long-term hydration resulted in lowering pH, and disintegration of formed ettringite. To overcome this problem, aluminum was added to the samples and formation of ettringite was monitored over a period of 660 days. Experimental results indicated that on availability of aluminum for reaction, primary and secondary ettringite minerals are formed and precipitated in these samples. Furthermore, the analysis indicated that the formed ettringite minerals remained stable during a hydration period of 660 days.

Author Information

Mohamed, AMO
Research Support and Services Unit, Department of Civil and Environmental Engineering, UAE University, Al Ain, United Arab Emirates
Hossein, M
Hart Crowser Inc., New Jersey
Hassani, FP
McGill University, Montreal, Quebec, Canada
Pages: 10
Price: $25.00
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Stock #: CCA10443J
ISSN: 0149-6123
DOI: 10.1520/CCA10443J