Copper recovery by cementing from waste solutions derived from the manufacturing/printing industry

Abstract

We report the optimal conditions for copper recovery on a laboratory scale through a cementation process from industrial waste solutions. As cementing agent, aluminum was employed from different sources: discarding aluminum from soda cans and turning chip and commercial meshes. The percentage of recovery is highly dependent on the exposed area of aluminum and chloride additions. It was determined that the optimal chloride concentration should be equal to or greater than 100 mM and the ratio between mass of aluminum and volume of copper solution must be greater than (42+/-4) mg/mL for mesh or shavings to obtain recoveries up to 90 %. For the case of aluminum from soda cans, this relation or the treatment time should be increased to reach the same relevant recoveries. As revealed by Scanning Electron Microscopy and X-Ray Diffraction experiments, the obtained copper is polycrystalline and dendritic, with low percentage of oxidized compounds. Under the conditions tested, the source of aluminum used does not seem to affect the quality of the product obtained. The conditions studied allow to scale the procedure and thus achieve the recovery of a metal of high economic value and reduce the environmental impact of industries such as the manufacture of printed circuits.