Comprehensive review on alkaline dissolution of aluminosilicates and its role in the mechanisms and properties of geopolymers and alkali-activated materials

Using industrial by-products as a source of aluminosilicate precursors (APs) for alkali-activated materials (AAMs) and geopolymers synthesis offers a valuable solution for managing increasing waste streams and reducing landfill reliance. Nevertheless, to successfully convert diverse APs into materials with consistent performance at an industrial scale, unified dissolution and testing methods for evaluating geopolymerization reactivity are essential. The dissolution kinetics of aluminosilicate minerals significantly influence the nanostructural evolution of geopolymeric materials, and consequently their final properties, by determining the composition and characteristics of the resulting hydrated phases. However, the primary factors governing alkali–aluminosilicate reactions are not yet fully understood. To this end, this review meticulously examines the theoretical and experimental mechanisms, as well as advanced simulation models used to elucidate geopolymerization. Additionally, it addresses the primary factors influencing the dissolution of aluminosilicate precursors in alkaline environments, including alkalinity, activator type and concentration, precursor fineness, impurities, leaching temperature, and contact time. The findings revealed that the dissolution of aluminosilicates critically influences the properties of geopolymeric materials. Consequently, understanding the initial dissolution behavior of Al, Si, and other elements in alkaline solution under varying conditions is essential for selecting appropriate precursors and tailoring the formulation of geopolymers and alkali‑activated binders for specific applications.