STUDY OF MIXTURES COMPOSED OF SCHEELITE RESIDUES AND DIFFERENT TYPES OF SOILS INTENDED FOR PAVEMENT
Mixtures study; Soils; Scheelite residues; Paving.
Over time, the need to reuse solid waste increases to reduce the environmental impacts caused by its storage. Mining is an activity that generates a significant volume of tailings that result from the ore beneficiation process. The scheelite beneficiation process causes a high amount of waste and its largest Brazilian deposit is located in the municipality of Currais Novos, in the scheelite province comprising the Brejuí, Barra Verde, Boca de Laje and Zangarelhas mines. Thus, this research intends to analyze the use of these residues of the coarse, fine and benefited types in mixtures with three local soils, for application in layers of pavements for adequate disposal of these residues. From data obtained in previous research by Barreto (2020), Costa Filho (2017) and Souza (2019) optimized mixtures were obtained to verify possible classification in granulometric gradings of national and international standards with residue proportions of 20, 40 and 60 %. The mixtures of the residue with Soil 01 showed more significant effects because it has coarser granulometry and zero plasticity, demonstrating greater potential for use in road paving. Solo 02 and Solo 03 did not allow compliance with the analyzed regulations due to their higher proportions of fine materials and greater plasticity. According to the Unified Soil Classification System (USCS) and the Highway Research Board (HRB) all mixtures with Soil 01 were considered as coarse-grained materials. In view of its use as base course material, the mixture of Solo 01 with 20% of processed waste made it possible to fit into the “D” and “E” gradings of national and international standards and all mixtures with 20% of waste thickness allowed framing in the “E” grading.