Work

Use of Magnetite Derived from Acid Mine Drainage in the Stabilization of Foam for Foamed Mortar

Year: 2025

Type: article

Abstract: Foam stabilization is fundamental in the production of foamed concrete, widely used in civil construction due to its applications in thermal insulation and structural weight reduction, both of which contribute to the energy efficiency of buildings. The foam acts as an air-entraining agent, providing the concrete with low density and enhanced thermal and acoustic properties. Recently, magnetite extracted from acid mine drainage (AMD) has been studied as a foam-stabilizing agent in foamed concrete, offering a sustainable solution for the use of coal tailings. Due to its magnetic properties, magnetite has proven effective in improving foam stability, ensuring a more uniform distribution of air bubbles within the concrete mix. The aim of this study was to produce foamed concrete (FC) using magnetite as a stabilizer for foam generated by mixing water with amide 90. The study also evaluated combinations with two types of cement (CP II Z and CP V ARI) and varying amounts of sand. The results showed that increasing the amount of magnetite led to a reduction in mechanical strength (both compressive and flexural tensile strength), as well as in dry and saturated density and thermal conductivity. Meanwhile, porosity and water absorption increased. The properties of the foamed concretes ranged as follows: compressive strength from 0.62 MPa to 7.33 MPa, porosity from 31.8% to 75.6%, and thermal conductivity from 0.54 W/mK to 0.17 W/mK.

Source: Sustainability

DOI: 10.3390/su17114986