2026 Matar Oxidants and accelerants in gold cyanidation

Gold cyanidation remains one of the most important hydrometallurgical processes in the mining industry. Gold dissolution kinetics and cyanide consumption are governed by coupled anodic–cathodic electrochemical reactions and influenced by pulp pH, particle size, cyanide concentration, mineralogy, and solution chemistry. Despite extensive studies on individual additives in gold cyanide leaching, a coherent synthesis of oxidants and leaching accelerants in modern gold cyanidation remains lacking. The main purpose of this paper is to present a critical review of the literature on leaching accelerants and oxidants used to enhance gold cyanide leaching kinetics and reduce cyanide consumption. The literature highlights that iron sulfide minerals, found in gold ores, can significantly increase cyanide and oxidant consumption through increased oxidant demand, surface passivation, and galvanic interactions that suppress gold dissolution kinetics. This review article summarises the leaching accelerants used, where lead nitrate plays a central role in gold cyanide leaching, and emphasises that its effectiveness is associated with suppression of sulfide-related passivation and favourable modification of surface electrochemistry of gold. The synergistic effects of leaching accelerants with different oxidants on leaching performance are also assessed, with emphasis on their electrochemical roles.