Waste valorization of iron ore tailings in Brazil: Assessment metrics from a circular economy perspective

The use of iron ore tailings (IoT) as an alternative mineral source can improve the sustainability of the mining process. Therefore, this study was conducted to describe the parameters of interest, including waste generation, and electricity and water consumption, in the iron mining activity of the Iron Quadrangle in Minas Gerais, Brazil, between 2010 and 2018. An increase of 65% of IoT generation was observed, which was accompanied by an increase of 70% and 90% in water and electricity usage, respectively. Recognizing this, a decision-making process for the waste valorization of iron ore processing was systematized with the criteria of classification, potentiality, quantity/feasibility, and applicability (CPQvA). Criticality indices were defined for a qualitative assessment of potential products and possible applications in other industrial sectors. The analyses performed showed interesting possibilities for alignments with circular economy practices, through industrial symbiosis, with the use of IoT as raw materials in the paving, ceramic, cement, and concrete industries.