Gold in Tailings — Mineralogical Characterisation and Metallurgical Implications

Gold extraction is significantly influenced by mineralogical factors, often leading to substantial losses in tailings. This paper aims to explore the mineralogical characterization of gold lost in tailings and its metallurgical implications. The research methodology includes deportment studies and characterisation techniques used to identify un-recovered gold particles. Results reveal that gold losses primarily occur as liberated particles or as fine gold locked within sulfide and non-sulfide minerals, with the latter being more prevalent. Factors such as grain size, surface coating, and the presence of cyanide or oxygen-consuming minerals substantially affect gold recovery. The study highlights that the encapsulation of fine gold in other minerals, whether as visible inclusions or invisible submicroscopic gold, is the leading cause of poor recovery rates in gold processing. With the ongoing depletion of free-milling gold ores, the significance of studying refractory ores is underscored, as these investigations are crucial for enhancing plant performance and identifying the causes behind gold losses. Additionally, the mineralogical characteristics of gangue minerals within gold ores and tailings may pose potential challenges to extraction processes due to the presence of harmful minerals.