Abstract
Thermal activation of bauxite has been proposed to enable bauxite dissolution at a reduced digestion temperature and also to reduce the organic content in the liquor. Research has been carried out on phase transformation of its main hydroxide components (gibbsite , boehmite and kaolinite ) during calcination. However, there is limited information available on phase bauxite phase transformation during thermal activation . In this study, two bauxite ore samples were heated from 25 to 700 °C at a rate of 50 °C/min while monitoring the phase transformation using Rigaku in situ XRD. Different phase transformation pathways for gibbsite in the bauxite compared with pure gibbsite was observed. Boehmite and kaolinite in bauxite behaved similarly to their pure phases. The temperature of phase transformation depends to some extent on the bauxite sample. Samples were also characterised by scanning electron microscopy (SEM) to reveal changes in the microstructure.
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Acknowledgements
The authors gratefully acknowledge the financial support from the Advance Queensland Research Fellowship supported by Rio Tinto and Queensland Government (Grant ID 2015003035). We acknowledge the facilities, and the scientific and technical assistance, of the Australian Microscopy & Microanalysis Research Facility at the Centre for Microscopy and Microanalysis, The University of Queensland. We thank Warren Staker (Rio Tinto) for helpful discussions and support for this project.
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Peng, H., Vaughan, J. (2018). In-Situ XRD Investigation of Bauxite Dehydroxylation. In: Li, B., et al. Characterization of Minerals, Metals, and Materials 2018 . TMS 2018. The Minerals, Metals & Materials Series. Springer, Cham. https://doi.org/10.1007/978-3-319-72484-3_3
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DOI: https://doi.org/10.1007/978-3-319-72484-3_3
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