Stability of solid residue after integral treatment of acid mine drainage

Abstract

Acid mine drainage is a challenging environmental problem caused by mining activities. Long-term copper ore exploitation and vast amounts of mining waste lead to severe soil contamination as well as river and groundwater pollution. In this paper, research is focused on utilizing waste mine waters and off-balance parts of the mine deposit (such as flotation tailings) and converting their negative characteristics to an environmentally friendly one. In the authors’ previous work, acid mine water from Robule, which is part of the Bor copper mining and smelting complex in Serbia, was successfully treated using flotation tailings, and the resulting solution was suitable for safe discharge. This paper investigates the characteristics of the solid residue that remained after the treatment of the modified flotation tailings in order to evaluate the possibility of its safe disposal back into the environment. The solid residue was subjected to TCLP and EN 12457-4 tests as standard procedures that assess the leaching characteristics of a material. The solid residue was also exposed to long-term leaching with melted snow to simulate environmental conditions for one year. This drainage water was analyzed and compared with the results of the standard leaching procedures. The investigated treatments lead to improved economic and environmental effects, while the process itself is adjusted to preserve the environment.