Use of tailings from the limestone calcination industries of the state of ceará with a focus on repair of environmental damage

Abstract

The residues generated in the limestone calcination process form piles sources of degradation of the environment and obstacles to the good progress of the activities of the producing units. The use of these tailings might generate benefits to the environment, as well as improvements to the job of the workers, besides being another source of income for the local calcination industries. This study was developed in the sense of the rational and economic use of these residual materials in the paving of roads and in the construction of landfills that require stabilized soil and, consequently, good consistency. Initially, waste was collected from three producing provinces of lime in Ceará, one of which is located between the municipalities of Coreaú and Sobral; another in Forquilha; and the third in Quixeré. The samples were mixed with a clay soil, consisting of soil-reject samples with residue ratios of 0% (zero), 20, 30, 40, 50, 60, 70 and 80%. Geotechnical tests were performed to determine their granulometry and respective California (CBR), plasticity (IP) and group (IG) indices. As result, soil physical strength increased by incorporating the reject in the samples, noting that a clay soil with physical characteristics not recommended for use in road construction could be useful for this purpose if stabilized with the residues of lime industries, promoting the environmental damage repair in the area of the producing units and a rational destination for the wastes.