Effective Recovery Process of Copper from Waste Printed Circuit Boards Utilizing Recycling of Leachate
Joona Rajahalme, Siiri Perämäki, Roshan Budhathoki, Ari Väisänen
Abstract
Abstract This study presents an optimized leaching and electrowinning process for the recovery of copper from waste printed circuit boards including studies of chemical consumption and recirculation of leachate. Optimization of leaching was performed using response surface methodology in diluted sulfuric acid and hydrogen peroxide media. Optimum leaching conditions for copper were found by using 3.6 mol L −1 sulfuric acid, 6 vol.% hydrogen peroxide, pulp density of 75 g L −1 with 186 min leaching time at 20°C resulting in complete leaching of copper followed by over 92% recovery and purity of 99.9% in the electrowinning. Study of chemical consumption showed total decomposition of hydrogen peroxide during leaching, while changes in sulfuric acid concentration were minor. During recirculation of the leachate with up to 5 cycles, copper recovery and product purity remained at high levels while acid consumption was reduced by 60%.