Biosolubilization of copper from waste electric cables

The paper reports on results from a laboratory tests for bacterial leaching of copper from scrap cables. The studied material is a reject fraction obtained after dismantling and separation of electric cables during recycling of end-of-life vehicles (ELV). The copper has been met predominately in pure metallic form as tiny irregular shaped wires often coated with tin and well liberated from the plastic isolations. For bringing copper in solution, a bacterially assisted agitative leaching with mixed consortium of mesophylic microorganisms has been chosen. Continuous bacterial adaptation of the cultures to the substrate has been envisaged in order to provide an efficient way for ferrous iron regeneration during the leaching. It has been established that under optimal conditions of pH, density and temperature it is possible to recover nearly the total copper within short leach duration. The obtained pregnant leach solution could be subjected to subsequent copper recovery via solvent extraction, while the solid leached residue could be considered as non-metallic material containing plastics suitable for recycling.