Análise da viabilidade técnica da produção de compósitos cerâmicos utilizando resíduos de minério de ferro da Barragem do Fundão e escória de alto-forno à carvão vegetal

Abstract

Industrial activities generate waste that can be reused, such as blast furnace slag and foundry sand. Besides, we have the extraction of iron ore, whose processing produces waste deposited in dams. In 2015, the Fundão Dam, located in Mariana (MG), collapsed, resulting in the pouring of million cubic meters of waste from the iron ore processing, causing a environmental disaster. Thus, this work aims to analyze the technical feasibility of producing ceramic composites based on iron ore residues from the Fundão Dam, charcoal blast furnace slag, and foundry sand for civil construction application. The raw materials were collected, oven-dried, and characterized by chemical, mineralogical, morphological, granulometric composition, thermal analysis, leaching, and density. After the raw materials’ characterization, 25 composites were developed varying the raw materials’ content. These were burned at temperatures ranging from 900ºC to 1250ºC. The ceramic composites were submitted to module tests of flexural strength, water absorption, linear shrinkage, and density. After characterizing them, composites 2, 21, and 24 were selected to individually analyze each raw material’s performance through chemical, thermal, mineralogical, morphological, and leaching analyses. Composites 21 and 24 stood out since they met the minimum value regarding the flexural strength module of 12 MPa. The increase in the obtained mechanical properties values occurs due to the temperature rise, causing the synthesis of new amorphous and crystalline formations. The results allow us to conclude that these residues associated with each other can be used in civil construction materials, contributing to decrease the extraction of natural resources, in addition to allowing their correct destination, reducing the impacts on the environment, and improving the quality of life of the society that lives in their surroundings.