Valorization of Brazilian waste foundry sand from circular economy perspective

The manufacturing and processing industries play a vital role in the Brazilian economy. However, they also produce significant waste from natural resources, much of which is disposed of in industrial landfills. To promote sustainability, it is essential to extend the life cycle of industrial waste by incorporating it into new production cycles. In this study, we evaluated the solid industrial residue (foundry sand) with the CPQvA system, in which the environmental class is evaluated by the classification criterion, chemical and mineralogical potential is analyzed, quantity and viability are identified, and applications are suggested. Each CPQvA system criterion includes specific questions defining the criticality index (Ic). Through multicriteria valuation, decision-making confidence is increased. We evaluated four products as possible candidates for the valorization of foundry sand: asphalt mass (P1), concrete blocks for civil construction (P2), hexagonal concrete blocks for interlocking pavement (P3), and mortar (P4). After assessing the environmental impact and economic feasibility, applications P1, P2, and P3 were found to be the most favourable for valorizing foundry sand.