Alkali activation of paper industry lime mud and assessment of its application in cementless binder

Abstract

This study revealed that the application of lime mud (LM) aids in construction materials that is sustainably economical, energy-efficient, and environmentally beneficial. A 2 M NaOH solution composed of 70% LM and 30% NaOH dissolved LM, and formed more reactive calcium hydroxide and carbonates, like thermonatrite and Pirssonite. It was confirmed with XRD, FTIR, and TGA of activated LM. Activated LM and untreated LM were used to prepare blends with ground granulated blast furnace slag (GGBFS) and silica fume. Activated LM was found to be compelling in the improvement of the reactivity of binder paste for all substitution extents and resulted in superior compressive quality in comparison to binder with untreated LM. Mineralogical analysis and an isothermal calorimeter showed the development of more hydration products and heat of hydration in binder pastes with activated LM. The leaching test and life cycle analysis also highlight the effectiveness of the proposed method.