2024

Heponiemi, Anne; Pesonen, Janne; Tynjälä, Pekka; Lassi, Ulla

Large amounts of metal sulfates are formed annually in industrial activities. Until now, there has been no cost-efficient technical method for the treatment of sulfate wastes. In this article, we present a study on the reuse of waste sodium sulfate solution from battery chemical production in the synthesis of alkali-activated materials (AAMs). Blast furnace slag was used as a raw material for the synthesis of AAM, and it was mixed with different ratios of sodium hydroxide and waste sodium sulfate solution. Characterization results showed that prepared materials had a similar kind of phase structure and a typical AAM composition. In addition, the chemical stability of the prepared AAMs was at a satisfactory level, and they obtained a high mechanical strength, 13.3 MPa, when up to 40 wt % of waste sulfate was added. Therefore, a waste sulfate solution is a potential raw material for the synthesis of AAMs.