Processing of Waste Copper Converter Slag Using Organic Acids for Extraction of Copper, Nickel, and Cobalt

• Main Authors: Pratima Meshram, Uday Prakash, Lalit Bhagat, Abhilash, Hongbo Zhao, Eric D. van Hullebusch
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Minerals
• Subjects: converter slag; citric acid; leaching; metal-water-citrate system; selectivity
• Online Access: https://www.mdpi.com/2075-163X/10/3/290

An innovative, economical, and environmentally sound hydrometallurgical process has been proposed for recovering Cu, Ni, and Co from copper-rich converter slag by organic acids. In the leaching experiments, the effects of organic acid concentrations, pulp density, temperature, and time were investigated. Optimum recovery of 99.1% Cu, 89.2% Ni, 94% Co, and 99.2% Fe was achieved in 9−10 h at 308 K (35 °C) temperature and 15% pulp density with 2 N citric acid using <45 µm particles. Pourbaix diagrams of metal-water-citrate systems were supplemented to examine solubility of ligands at the desired conditions. Furthermore, the leaching mechanism was based on the SEM-EDS (energy-dispersive X-ray spectroscopy) and XRD characterization as well as the leaching results obtained.