Evaluación del consumo de cianuro en la lixiviación del oro mediante la aplicación de peróxido de hidrogeno

Abstract

Our main objective in this research focuses on evaluating the impact of the use of hydrogen peroxide (H₂O₂) in gold leaching, a crucial chemical process for the extraction of this precious metal. The main objective is to optimize the consumption of cyanide (NaCN), a costly and potentially environmentally harmful reagent, by controlled incorporation of H₂O₂. Several experimental tests were conducted, comparing the leaching process in the absence and presence of H₂O₂. In the tests without H₂O₂, the concentration of gold in solution reached a maximum of 1.93 g/m³, with a total consumption of 256.5 ml of NaCN. The pH remained stable between 10.5 and 12, which is critical for the efficiency of the process. With the addition of H₂O₂, variations in gold extraction efficiency were observed. In the second test, where 60 ml of H₂O₂ were added, the gold concentration reached 1.86 g/m³ using 198 ml of NaCN. In the third test, with further addition of 75 ml of H₂O₂, the gold recovery improved significantly, reaching 2.05 g/m³, with a reduced consumption of 188 ml of NaCN. Finally, in the fourth test, the stepwise addition of 90 ml of H₂O₂ resulted in the highest efficiency, reaching 2.2 g/m³ with only 158 ml of NaCN. The results demonstrate that the incorporation of H₂O₂O₂ not only reduces cyanide consumption, but also improves gold recovery. These findings are fundamental for the development of more sustainable and efficient processes in the mining industry.