Marble Waste Valorization through Alkali Activation

New Metakaolin-Based Geopolymers with the Addition of Different Types of Waste Stone Powder

The search for new alternative raw materials and their subsequent use supports the sustainability of natural resources. This article describes the use of waste stone powder (WSP) in geopolymer synthesis. Five different types of WSP (feldspar, limestone, marlstone, dolomite, marble) were comprehensively characterized and their influence on the resulting properties (especially mechanical and textural properties, setting time and structure) of metakaolin-based geopolymer composites was investigated. Their comparison with a geopolymer composite containing only quartz sand has revealed that WSP additions have a small but positive effect on the mechanical or textural properties of geopolymers. Moreover, setting time measurements have shown that waste stone powders can be used as an accelerator of geopolymer reaction solidification. The results demonstrated that the mentioned types of WSP, previously landfilled, can be used for the preparation of geopolymers. This can help reduce the environmental burden.

Editorial for Special Issue: Alkali Activated Materials: Advances, Innovations, Future Trends

Alkali activated materials (AAMs), also named geopolymers or inorganic polymers, are materials that are produced when alkaline solutions react with precursors containing aluminosilicate phases [...]