The Impact of Acid Concentration and Temperature on Copper Leaching from Waste SIM Cards

This study investigates copper recovery from waste SIM cards using hydrometallurgical acid leaching with nitric acid. Microchip components were mechanically separated from their plastic substrates prior to leaching experiments with varying nitric acid concentrations (2 M-6 M) and temperatures (40-80°C) for 180 minutes. Copper dissolution was analyzed using atomic absorption spectrophotometry at different time intervals. Results demonstrated that acid concentration significantly enhanced copper dissolution, with 4M and 6M nitric acid achieving similar maximum recovery rates of approximately 74% within 120 minutes. Temperature variations (40-80oC) showed minimal impact on extraction efficiency, suggesting that the process is not thermally activated under these conditions. Based on the experimental conditions tested, 4M nitric acid at 40oC was identified as the most economically favorable condition, achieving 72.9% Cu recover. This study provides valuable insights for sustainable precious metal recovery from electronic waste.