Development of a methodology to characterize activated carbon involved in gold recovery in ore processing (ULiège)

Abstract

Gold recovery from low-grade ores relies predominantly on cyanidation followed by adsorption onto granular activated carbon (GAC). However, inorganic fouling (IF) of GAC is believed to significantly reduce its gold adsorption capabilities and, consequently, process efficiency. This study presents a methodology to characterize inorganic fouling on activated carbon used in carbon-in-pulp (CIP) and carbon-in leach (CIL) circuits. A systematic protocol was developed to identify, map and quantify inorganic contaminant phases on GAC at the microscale using scanning electron microscopy-based automated mineralogy (SEM-AM). This approach enables detailed assessment of inorganic fouling content and heterogeneity, while also providing crucial insights into its development and state. Furthermore, it allows for site specific optimization of GAC regeneration strategies, promoting more sustainable resource use and ultimately contributing to improved gold recovery.