Mechanical properties of lightweight aggregates produced from mine tailings via alkali-activation

Asadizadeh M.; Hedayat A.; Tunstall L.; Neira T.M.; González V.J.A.; Alvarado V.J.W. · 57th US Rock Mechanics/Geomechanics Symposium (2023) · DOI: 10.56952/arma-2023-0838

Resumen

This study investigated the production of lightweight aggregates (LWAs) from mine tailings (MTs) using an alkali activation approach. The main objective was to reduce the environmental and cost impacts of handling tailings while producing a useful material for the construction industry. The alkali activation process was used to activate the aluminum oxide and silicon dioxide in MTs to produce LWAs, which were then characterized for physical properties. A pelletization technique was practiced, using a disk granulator machine to spray a 10 M NaOH solution on the MTs with a liquid/solid ratio of 0.25. The produced LWAs were cured at temperatures 70 °C±2°C, and the properties of the resulting materials were assessed as a function of the type of fly ash used (class C and F fly ash). Results showed that using Class F fly ash is more successful for making LWAS, and its increasing percentage in the mixture led to increased compressive strength and relative and bulk densities and decreased water absorption and porosity. This study highlights the potential for producing sustainable construction materials from MTs using alkali activation, which could reduce the environmental impacts of MTs while producing useful materials for the construction industry.

Instituciones: Universidad Nacional de Trujillo