One-part inorganic polymers from residues only: Biomass ash activation of Fe-rich slag

The formation of inorganic polymers solely from industrial residues was investigated. Non-ferrous slag, an iron silicate precursor, was combined with biomass ash from electricity generation, which contains potassium, providing the alkalinity needed to dissolve and polymerize the slag. The reactivity in calorimetry was shown to be comparable with maize ashes, which have already proven in past research to provide strong geopolymers when combined with metakaolin. For optimised ash/slag and water/solid mass ratios of 0.9 and 0.15 respectively, the maximum compressive strength of pressed samples attained was 10.4 MPa. This low strength was associated with a low reaction extent, observed by attenuated total reflectance Fourier-transformed infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM), as well as with the formation of gypsum, observed using a combination of SEM and thermogravimetric analysis (TGA).status: publishe