A Preliminary Insight into the Effects of Tailing Wastes Addition on Metakaolin-based Geopolymers

Geopolymers are inorganic binders made up by alkali activated aluminosilicates tetrahedrons. Given during the 1970s by Davidovits with reference to inorganic or mineral materials, geopolymers have good chemical properties, stability in alkaline or acidic media, high mechanical strength, and their synthesis is based on the polycondensation of aluminosilicate tetrahedrons. In the meantime, after the high failures rate of tailing dams the storage of mining wastes became difficult, leading to considering other storage destinations. Combining these two aspects, this study deals with the effects of the addition of some iron ore tailings in different binders of metakaolin-based geopolymers. The effects of iron tailing wastes addition, the composition in mass percentage, and the calcination time are independently evaluated in terms of compressive strength. Their mutual effects are also studied, highlighting the need for an in-depth control of the calcination conditions of metakaolin and the composition of the geopolymer samples to have the desired strength properties.