Recovery of base metals from waste cpu by hydrometallurgical processes

Study on base metals, such as tin, nickel, iron, copper, from waste CPU has been performed using a hydrometallurgical route which consisted in oxidative leaching and chemical precipitation. The chemical leaching has been applied on concentrate obtained after milling and magnetic separation of these scraps. Four replicate leaching tests, using 1.89M sulfuric acid as leaching reagent and 10 ml of hydrogen peroxide (30%wt) as oxidant at 70°C for 24 hours were performed. The obtained results after this chemical treatment showed that average of extraction yield for copper was 1.37%, 70.82% for nickel, 99.86% for iron and 98.74% for tin,. All four pregnant solutions were mixed and then shared in two in order to study the precipitation of Sn, Fe and Ni by adding solution of NaOH with a concentration of 10% and 30%, respectively, for pH level augmentation until 7. The total recovery of tin from solution was achieved, while nickel and iron were precipitate in a very low concentration probably due their high solubility and to the presence of other elements.