IMPORTANCE OF THE CHARACTERIZATION OF COAL-DERIVED ASH FOR APPLICATION IN THE ARCHITECTURE, ENGINEERING, AND CONSTRUCTION INDUSTRY

Abstract

The growing demand for sustainable solutions in the Architecture, Engineering, and Construction (AEC) industry encourages the use of residues from industrial processes as alternative materials to Portland cement—whose production is highly CO₂-emissive—or in the manufacture of cementitious matrices. Among these residues, ashes resulting from the combustion of mineral coal in thermoelectric power plants stand out, as they represent a significant environmental liability. In this context, the present study aimed to chemically, mineralogically, and morphologically characterize bottom ash generated at the Pecém Thermoelectric Power Plant (Ceará, Brazil) after beneficiation, in order to identify potential applications for this processed residue. The methodological procedures included ash beneficiation through granulometric fragmentation and sieving; determination of chemical composition by X-ray fluorescence; identification of mineralogical composition by X-ray diffraction; and morphological analysis by scanning electron microscopy. The results showed that the beneficiated coal bottom ash is rich in SiO₂, Al₂O₃, and Fe₂O₃, meeting the chemical requirements of NBR 12653 for classification as a Class C pozzolan. In addition, the presence of an amorphous halo in the diffractogram and a spherical morphology with vitreous, friable particles confirmed its pozzolanic potential. Therefore, the beneficiated bottom ash presents suitable characteristics for partial replacement of Portland cement in mortars, concretes, and other cementitious matrices, contributing to the reduction of environmental impacts and to the achievement of sustainable production and consumption targets established in Sustainable Development Goal 12.

DOI: https://doi.org/10.56238/sevened2025.036-116