Inertization of mine tailing via cold consolidation in geopolymer matrix

he consolidation via geopolymerisation is a room temperature alkaline chemical reaction of condensation between SiO2 and AlO2 monomers. Such a matrix can retain a large number of cations to compensate for the Al+3 in place of Si+4 in the tetrahedra. Arsenic-rich mine tailings from a gold mining site were activated with NaOH solution and commercial Na-Silicate (Na2O/SiO2 = 3) to produce a no-hazardous final material. Granulated blast furnace slag and metakaolin were used as co-binders to optimize the formulations. Leaching test was used to evaluate the inertization capability of the matrix after curing times of 7 and 28 days. The leaching results show that increasing curing time there is a significant decrease of As leaching due to the better consolidation of the material. Leaching of Cu, V, Ba and Zn significantly decrease, while Ni and Cr remain almost constant and Sb slightly increases.