Sustainable alkali binders: Waste activating wastes
May 27-June 1, 2018
Alkaline binders usually requires two main components, namely the solid precursor, rich in alumina and silica (preferably in an amorphous state); and the activator solution, based on an alkali metal (usually sodium or potassium). The role of the precursor is commonly assumed by a residue, usually fly ash or blast furnace slag with significant economic and environmental benefits. However the activator is frequently prepared with first grade commercial reagents (usually sodium or potassium hydroxide and sodium or potassium silicate), which significantly increases the financial costs and severely dilutes the environmental initial advantages, due to the high CO2-eq released during the production of the reagents. These drawbacks associated with the activator severely hinder the wide spreading of this technology severely making the development of low cost activators a major research target. Therefore, a strong expectation regarding the application of industrial residues as the main (or even the sole) constituent of the activators – and not just as the precursor – is rapidly growing. The aim of the present paper is thus to analyse the potential application of some by-products, in this case from the aluminium foundry industry, as the alkali activator of two different precursors: fly ash type F (FA) and blast furnace slag (BFS).
Ana Fernández-Jiménez, Cristelo N, Miranda T, and Palomo A, "Sustainable alkali binders: Waste activating wastes" in "International Conference on Alkali Activated Materials and Geopolymers: Versatile Materials Offering High Performance and Low Emissions", J. Provis, University of Sheffield C. Leonelli, Univ. of Modena and Reggio Emilia W. Kriven, Univ. of Illinois at Urbana-Champaign A. Boccaccini, Univ. of Erlangen-Nuremberg A. Van Riessen, Curtin University, Australia Eds, ECI Symposium Series, (2018). http://dc.engconfintl.org/geopolymers/53