Title: A novel method for extraction of alumina from red mud by divalent alkaline earth metal oxide and soda ash sinter process

Authors: Shib Narayan Meher; Balakrushna Padhi

Addresses: Research and Development Department, M&R Complex, National Aluminium Company Limited, Damanjodi, Dist.-Koraput, PIN-763008, Odisha, India ' Research and Development Department, M&R Complex, National Aluminium Company Limited, Damanjodi, Dist.-Koraput, PIN-763008, Odisha, India

Abstract: A novel method for extraction of alumina from red mud by divalent alkaline earth metal oxide and soda ash sinter process followed by thermo chemical leaching in suitable caustic concentration at 105°C for different times is presented in this paper. During sintering sodalite/cancrinite, gibbsite and boehmite in red mud is converted to sodium aluminate as well as stable phases of divalent alkaline earth metal ferrite, titanate and silicate. In the above novel economic process and extraction of alumina from red mud of 97.64%, 98.70% and 99.50% was achieved using CaO, MgO and BaO respectively. The morphological behaviours of sinter products and leached products were studied by using scanning electron microscope (SEM) and X-ray diffractometer (XRD).

Keywords: red mud; sintering; leaching; divalent alkaline earth metal oxide; alumina extraction; soda ash; sodium aluminate.

DOI: 10.1504/IJEWM.2014.059932

International Journal of Environment and Waste Management, 2014 Vol.13 No.3, pp.231 - 245

Accepted: 27 Dec 2012
Published online: 13 May 2014 *

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