Electrochemical Recovery of Copper and Aluminum from B_22 LED Lamp PCBs: A Hydrometallurgical Case Study for E-Waste Valorization in Togo
YAKAOU Kodzovi *
MTWV (Management, Treatment, and Waste Valorization), Faculty of Sciences, University of Lomé, P.O. Box 1515, Lomé, Togo and Organic Chemistry and Environmental Sciences Laboratory (OCESL), Faculty of Sciences and Technology, University of Kara, P.O. Box 404, Kara, Togo.
SEGBEAYA Kwamivi N.
MTWV (Management, Treatment, and Waste Valorization), Faculty of Sciences, University of Lomé, P.O. Box 1515, Lomé, Togo and Organic Chemistry and Environmental Sciences Laboratory (OCESL), Faculty of Sciences and Technology, University of Kara, P.O. Box 404, Kara, Togo.
*Author to whom correspondence should be addressed.
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.
Keywords: E-waste, LED-B_22 lamps, metals, recycling, Togo