In response to increasingly stringent environmental regulations,an exploratory experimental study was conducted on the application of eco-friendly gold leaching agents in bio-oxidation gold extraction processes to assess the feasibility of replacing sodium cyanide with industrial alternatives.Under identical conditions of slurry concentration,leaching temperature,pH value,and leaching time,an exploratory experimental study was carried out on the gold leaching performances of 4 gold leaching agents:sodium cyanide,eco-friendly agent A,eco-friendly agent B,and eco-friendly agent C.Additionally,considering the actual conditions of the closed-loop liquid phase circulation in the cyanidation system,loop zinc powder replacement tests under identical conditions were performed on pregnant solutions obtained using the 4 agents.The study compared the effects of impurity ion accumulation on indices such as replacement performance during long-term closed-loop operations and explored potential mitigation strategies in hope that it can provide a set of scientific theories and pratical guidance for gold extraction.