Gravity Concentration of Gold-Bearing Ores and Processing of Concentrates: A Review

Gold has been one of the most valued metals throughout human history. Traditionally, gravity plants primarily utilized equipment designed to recover only coarse-grained free gold, including jigs, spiral separators, cone concentrators, shaking tables, sluices, and hydrocyclones. The introduction of centrifugal concentrators in the 1980s initiated a trend toward more compact, simplified, and low-maintenance circuits. The use of centrifugal concentrators such as Knelson, Falcon, Multi-gravity separator (MGS), Kelsey, and Itomak has significantly enhanced the recovery of fine gold particles. A review of studies comparing centrifugal equipment, highlighting their main technological advantages, and disadvantages is presented. Depending on their mineral composition, the concentrates obtained can be processed by various methods. Due to increasingly stringent environmental regulations, there is a growing trend to abandon pyrometallurgical methods in favor of developing hydrometallurgical methods for processing gravity concentrates. Particular attention is given to the intensive cyanidation of concentrates. The main technological advantages and disadvantages of intensive cyanidation reactors, specifically Consep Acacia, ILR Gekko, and August Irgiredmet are discussed. Additionally, examples of intensifying chemical reagents used as additives in the intensive cyanidation of concentrates, along with their main characteristics are provided.