Comparative Analysis of the Effect of Disposal in Tailings and Waste Rock Piles

Abstract

The disposal of tailings currently represents a major challenge in the Brazilian mining scenario. As a result of the accidents that have occurred in the last decade, the legislation has become increasingly demanding with regard to the disposal processes of these materials. Therefore, new disposal systems are being researched and studied to ensure safer, functional and efficient procedures. One of the strategies currently being evaluated is the implementation of piles with mixed disposal of tailings and waste rock. This study aims to compare the numerical modeling of two alternatives for mixed disposal systems in piles. The first considered an interlayer disposal of tailings and waste rock in an layered comingling system, and the second considered a homogeneous mixture of tailings (50%) and waste rock (50%) in a co-disposal system.The material characterization and geotechnical parameters were obtained from laboratory tests. To understand the stress-strain behavior, finite element analyses were performed using RS2 software. Additionally, limit equilibrium analyses were performed with SLIDE 2 to evaluate the stability of each system. The results obtained did not show significant differences between the two disposal systems, presenting similar safety factors, as well as deformations and displacements in the same order of magnitude. The studies performed show the opportunity to implement interleaved systems for tailings disposal as well as the need to conduct more detailed studies that evaluate more critical considerations in the structure.