Copper recovery from leach solution of waste printed circuit boards by pulse current electrodeposition

The copper recovery from waste printed circuit boards is of great significance to protect natural resource and environment. Direct current electrodeposition has been applied to extract metal from hydrometallurgical leach solutions. However, during the direct current electrodeposition process, concentration polarization and hydrogen evolution reaction often exist, which reduces current efficiency and metal recovery capability. In this work, a pulse current was applied to electrodeposit copper. The electrolyte was the leach solution of waste printed circuit boards obtained using a sulfuric acid-hydrogen peroxide system. The influence of process parameters in the leaching stage and the electrodeposition process on current efficiency were both investigated. The results showed that the current efficiency was 95.1% in pulse current electrodeposition, while that was only 90.9% in direct current electrodeposition. The increased current efficiency was proposed to be attributed to the fact that pulse current electrodeposition could improve the mass transfer of copper ions which suppressed concentration polarization and hydrogen evolution reaction. These results demonstrate that pulse current electrodeposition is a promising approach for recovering copper from waste-printed circuit boards.