589 ore treated, yielding savings 0.63$/t. The average total cyanide content in the solution was 0.14 ppm, completely harmless and below Maximum Permissible Limits. Figure 6 - Caro’s Acid cost ($/t) in cyanide destruction. 6. CONCLUSIONS • The optimization of Caro’s Acid process for free cyanide destruction in CIP cyanidation tailings at the Antapite processing plant was achieved with a molar ratio H2SO4/H2O2 between 1.3 and 1.4. This reduced total cyanide in the tailings dam from an average of 15.2 ppm in 2006 to 0.14 ppm in 2010, in compliance with Maximum Permissible Levels established by national mining and environmental legislation. • A significant reduction in Caro’s Acid consumption for free cyanide destruction in cyanidation tailings was achieved, from an average of 10.5 kg of Caro’s Acid per kilogram of cyanide up to 2006, down to 2.2 kg of Caro’s Acid per kilogram of cyanide in 2010. • The efficiency of cyanide destruction using the Caro’s Acid process increased substantially, from an average of 93.7% efficiency until 2006, reaching a maximum efficiency of 99.9%. • Through optimization of the Caro’s Acid process, treatment costs for cyanide destruction were reduced from an average of $0.93/t of ore treated until 2006 to $0.30/t in 2010, resulting in savings of $0.63/t. • Optimization of the Caro’s Acid process for cyanide destruction in CIP cyanidation tailings at the Antapite processing plant contributes to improved occupational safety and health, enhanced environmental protection by preserving local flora and fauna, and strengthened community relations. In the unlikely event of seepage into downstream groundwater bodies, contamination levels would be minimal, since the filtrate complies with Maximum Permissible Limits for total cyanide content. ACKNOWLEDGMENTS The author gratefully acknowledges Compañía de Minas Buenaventura S.A.A. for authorizing the dissemination of this technical paper. 1.22 0.87 0.70 0.84 1.02 0.91 0.61 0.42 0.30 0.93 0.93 0 0.2 0.4 0.6 0.8 1 1.2 1.4 2002 2003 2004 2005 2006 2007 2008 2009 2010 $/t Caro’s Acid Cost ($/t) Caro’s Acid Average Cost ($/t)
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