A Review of SART Process: Effective Processing Approach for Sophisticated Copper Bearing Gold Ores

The occurrence of dissolved copper in gold ores poses a persistent obstacle to conventional cyanidation operations. Copper forms highly stable copper-cyanide complexes that consume excessive cyanide and lime, depress gold dissolution efficiency, and complicate the treatment of cyanide-containing tailings. When the copper content in the leach liquor exceeds about 300–500 mg/L (often associated with ore grades above approximately 0.05–0.1 w.t%), the implementation of the SART (Sulfidation-Acidification-Recycling-Thickening) process becomes both economically advantageous and environmentally prudent. Since its first industrial deployment nearly two decades ago at the Telfer mine in Australia, SART has been successfully integrated into multiple gold operations worldwide, including Lluvia de Oro (Mexico) and Çöpler (Turkey). The process precipitates copper as a marketable copper sulfide while releasing cyanide for reuse in leaching, with reported free cyanide regeneration efficiencies commonly exceeding 85% under favorable operating conditions. In addition, SART may reduce reagent consumption and contribute to improved gold recovery and lower environmental risks associated with cyanide-bearing tailings. Despite these advantages, several factors governing SART performance remain only partly understood. The composition and stability of the copper-sulfide precipitate can be affected by impurities such as iron, zinc, and nickel, while variations in ore mineralogy and plant operation (particularly pH regulation, sulfide dosage, and thickener efficiency) strongly influence overall process economics. This review provides a comprehensive synthesis of the theoretical foundations and key chemical reactions underlying SART, examines laboratory-scale studies and industrial applications to highlight controlling operational parameters, and compares SART with alternative approaches to copper and cyanide recovery. Particular emphasis is placed on post-2018 developments, including advances in process control strategies, impurity management, and modified SART configurations reported in recent industrial and pilot-scale studies. Finally, the paper identifies research priorities related to process optimization, integration with complementary leaching or detoxification technologies, and strategies to expand the role of SART in advancing more sustainable and cost-effective gold processing.