Abstract:
Carbonaceous gold ores contain substantial organic carbon and sulfides, which readily cause the preg-robbing effect during cyanide leaching, seriously impairing gold recovery. Roasting pretreatment is a key approach to overcome the adsorption by carbonaceous matter and the encapsulation by sulfides. This paper systematically reviewed the research progress in roasting pretreatment technologies for carbonaceous gold ores with emphasis on the principles, influencing factors, and application effects of mainstream processes including oxidative roasting, microwave roasting, and vacuum roasting. Conventional oxidative roasting effectively destroys the carbonaceous structures and releases encapsulated gold through high-temperature oxidation, significantly improving gold leaching rates. However, it suffers from high energy consumption and environmental pollution. Improved processes such as oxygen-enriched roasting and suspension roasting show superior performance in enhancing reaction efficiency and reducing emissions. Microwave roasting utilizes electromagnetic waves for selective heating, offering advantages such as rapid processing, energy savings, and avoidance of sintering, which make it particularly suitable for refractory fine-grained gold ores, whereas its technological maturity still needs improvement. Vacuum roasting enables thermal decomposition of sulfides and gold liberation in an oxygen-free environment, fundamentally avoiding the generation of harmful gases like SO
2, and thus having significant environmental benefits, yet its high energy consumption and stringent equipment requirements limit its widespread application. By comparing the energy consumption, efficiency, and environmental performance of various roasting technologies, this paper provides a theoretical basis for process optimization and selection. It also points out that future efforts should focus on multi-technology coupling, parameter optimization, energy consumption reduction, and off-gas resource utilization, so as to promote the development of green and efficient pretreatment technologies for carbonaceous gold ores.