Transforming bauxite residue into high performance Inorganic Polymers: a feasible solution for all European refineries?

The sustainable use of industrial residues allows to lower the environmental impact of the construction industry. Bauxite residue (BR) is of high interest, because of its large volumes available. Although BR is considered to be highly alkaline for cementitious systems, it can be a suitable precursor for inorganic polymers (IPs) in case the material is transformed into a reactive glass through a heat treatment. This paper shows that BR produced in different European refineries can be converted to different reactive precursors with similar chemistry at temperatures of 1200 °C, considerably  lower than conventional cement production. Compressive strength up to 100 MPa, using solely alkali-activated treated BR (TBR) and sand, were achieved under ambient curing conditions. Sodium in the reactive precursor was identified in this work as one of the key elements in promoting the early and late age performance.