Copper extraction from scrap cables by biotechnological means

The papaer reports on laboratory results regarding bio leaching of metallic copper from cable-bearing scraps derived from recycling of end-of-life vehicles. The copper has been met in pure form as irregular shaped wires often coated with tin. The complex nature of the material renders both gravity and physicochemical separation unsuitable for efficient copper separation. Hence a bacterially assisted leaching with mixed consortium of mesophylic microorganisms has been tested for recevery of the remaining copper. Continuous adaptation of the cultures to the substrate has been envisaged in order to guarantee sufficient degree of ferric iron regeneration by bacteria during leaching. It has been established that under optimal leaching conditions such as acid consumption, pulp density, pH and temperature, it is possible to recover nearly 98 % of the copper in solution within acceptable leaching duration.