Synthesis and characterization of low temperature (<800°C) ceramics from red mud geopolymer precursor

This paper presents a way to valorize red mud for the production of potential structural materials, using geopolymer technology. Several compositions of red mud geopolymers were prepared with sodium silicate solutions. After sintering the red mud geopolymer products at 300-800 degrees C, their stability in water has been improved. The starting red mud was found to contain hematite, katoite, cancrinite and a few amount of diaspore, which hardly dissolved and participated in the geopolymerization reaction. However, the geopolymer gel formed was sufficient to bind the unreacted phases and form a high strength material with about 40 MPa after appropriate curing. (C) 2016 Elsevier Ltd. All rights reserved.