Caracterização da escória salina oriunda da reciclagem de alumínio para aplicação na área de materiais

Abstract

The practice of recycling aluminum from scrap is considered sustainable. It results in a significant reduction in energy consumption during the transformation process, and additionally, it eliminates mining activities. Slag, a byproduct of the metallurgical industry, has garnered interest from the scientific community due to its sustainable prospects and the possibility of reuse in various fields. This leads to cost reduction in material manufacturing, as this type of waste demonstrates applicability in diverse areas. In the scope of this study, salt slag from the secondary aluminum process was thoroughly evaluated concerning moisture content, particle size distribution, and determination of the bulk density of the raw sample. The slag exhibited moisture and density levels of 0.33% and 2.566 ± 0.050 g/cm3, respectively. Granulometric analysis classified this residue as a fine aggregate with easy dispersion. Energy dispersive X-ray spectrometry (EDX) revealed Al (35.03%), Cl (47.50%), K (6.35%), Ca (3.09%), and Fe (2.90%) in the raw slag. In leached slag, the predominant elements were K (12.25%), Ca (25.13%), and Fe (21.91%), while in leached salt, Cl (84.71%) and K (11.28%) prevailed. The magnetic material showed Fe (35.14%). X-ray diffraction (XRD) indicated the presence of Al2O3 in all analyzed materials, except in leached salt, suggesting that the slag contains aluminum that can still be reprocessed. Moreover, the magnetized material from leached slag revealed the presence of magnetite (Fe3O4), an iron oxide phase of technological interest in advanced oxidative processes. Considering these findings, it was observd throughout this characterization and study that salt slag has great potential for various applications, such as reuse in aluminum recovery processes, adsorption, catalysts, construction materials, ceramics, and advanced oxidative processes. Therefore, this metallurgical residue can contribute to the perspective of industrial symbiosis, proposing future implementation in companies within this sector.