Electrochemical Recovery of Copper and Aluminum from B_22 LED Lamp PCBs: A Hydrometallurgical Case Study for E-Waste Valorization in Togo

Abstract

Electroextraction is a promising method for recovering strategic metals such as aluminum and copper from e-waste. These metals play a central role in geopolitics and economic development. In Togo, e-waste production increased from 6,400 tons in 2016 to 8,392 tons in 2024, highlighting the growing interest in their recovery. This study focuses on the recovery of aluminum and copper from printed circuit boards of  LED lamps, which are commonly used in the country. After dissolving the metals with nitric and hydrochloric acids, electroextraction was carried out using specific electrodes. The pH of the solutions containing the reducible species ranged from 0.29 to 0.30 for  ions and from 1.26 to 1.27 for  ions. The measured temperatures ranged between 26.1 and 27.8 °C for  and between 25.8 and 26.8 °C for . An applied voltage of 1.89 V for copper and 2.89 V for aluminum was maintained throughout the process. Under these conditions, the reducible species remained in the form of  and  ions, respectively. A current intensity of 0.008 A enabled copper recovery over 9,000 seconds, while a current of 8.7 A was applied for aluminum over 21,600 seconds. The process allowed the recovery of 9 % of copper and 16 % of aluminum. The application of these results could help reduce environmental risks associated with the mismanagement of e-waste and preserve energy resources linked to metal extraction. Although modest, these performances reveal significant optimization potential. At an industrial scale, recovery could have reached 26.11 tons of copper and 281 tons of aluminum in 2023, from 1,243.4 tons of used lamps in Togo.