Development of alkali-activated mortar from iron ore tailings

Abstract

In this work, the authors explore the use of iron ore tailings (IOT) from a tailings dam as a recycled precursor material in producing a composite through alkali-activation technology. Two different composite types were evaluated: paste specimens made using only IOT and an alkaline activator, and mortar specimens using the same binder and quartz sand as fine aggregate. Three different grinding times were applied to activate the IOT; a NaOH solution was used as the alkaline activator with three molar concentrations (8, 10, and 12 mol/l); and, thermal curing of 100°C for 7 days was applied. These parameters were obtained by a hard-minitest (HMT) experimental procedure. The physico-mechanical properties of the composites were obtained, and the results showed a compressive strength up to 110.0 MPa, which is like high-performance Portland cement concretes and alkali-activated cements derived from well-established precursors reported in the literature using thermal cure.