Clean recovery of copper from waste printed circuit boards using ceric ammonium nitrate

A clean approach was proposed to recycle copper from waste printed circuit boards (WPCBs), which involved leaching, purification, and electrolysis. Ceric ammonium nitrate (CAN) was used as the leaching agent to dissolve copper from WPCBs, due to its strong oxidizing property and recyclability through electrolytic oxidation. The results showed that the copper leaching rate was 99.9 % under the optimized conditions.The leaching process of copper was in accordance with the mixed control model, and the apparent activation energy was 47.56 kJ/mol. After the leaching, the solution was purified to remove Ag and Sn by activated carbon, and the removal behaviors of Ag and Sn followed the pseudo-second-order model. Using the purified solution as the electrolyte to conduct the diaphragm electrolysis, copper with a purity of 99.998 % was produced at the cathode, and Ce3+ ions were simultaneously oxidized into Ce4+ ions at the anode. By using this process, copper was recycled from WPCBs, and CAN was regenerated.