Lixiviação em pilhas de minérios de ouro de baixo teor incorporada ao processo de tanques agitados, Carbon in leaching, uma alternativa econômica no norte do Uruguai

Abstract

This work was carried with the intention of obtaining an alternative to gold leaching route for low-grade minerals to an industrial plant that adsorbs gold actually by the Carbon in Leaching process in the Rivera Crystalline Island region, in Uruguay. The tests were carried out with sodium cyanide solutions in concentrations of 1000 mg / L using the rolling technique in vials bottle of 20 liters achieving recovery of 93.5% gold order and in columns 3 meters achieving extractions of order 77 5% where the gold was quantified by the loss fire method to followed by atomic absorption spectrometry. These results allowed to establish operating criteria, design, process flow diagram, investment cost of US $ 23,471,251 and cost of operation of US $ 6,373,056 for a heap leaching plant in permanent to treat 1,000,000 tons of ore per year of low-grade ore of (0.45 to 0.659) grams per ton with a particle size passing 80% of 12.8 mm and annual production can reach about 455 kg of gold, corresponding to an increase of about 24% of production actually. For feasibility analysis considered existing production lines which are: adsorption, desorption, electrolysis and casting. The project has economic viability with a Net Present Value of US$ 8.649.276, an Internal Rate of Return of 31.21% and discounted payback period of 2.10 year operating for three years.