Wastes materials in geopolymers

A promising process, often indicated as geopolymerization, describes the formation of an aluminosilicate amorphous matrix where Ca is absent or contained in low amount. Geopolymers are obtained from an aluminosilicate powder activated by alkaline solutions and the synthesis process involves three separate stages: dissolution, condensation and polymerization. Sodium silicate is used for the activation of many kinds of aluminosilicate precursors and hazardous wastes. In the present work, three case studies of solid and liquid, hazardous and non-hazardous wastes added in geopolymers will be presented. The results show the versatility of this technique and the possibility to obtain geopolymers from aluminosilicate-based waste and to immobilize their hazardous ions.