Flotación Colectiva Pirita-Arsenopirita-Oro de los Residuos de Noche Buena, Zac., y su Separación en Concentrados Pirita-Oro y Arsenopirita
Flotación Colectiva Pirita-Arsenopirita-Oro de los Residuos de Noche Buena, Zac., y su Separación en Concentrados Pirita-Oro y Arsenopirita
DOI: https://doi.org/10.22533/at.ed.4972527014
Palavras-chave: Residuos de oro, oro asociado a sulfuros de hierro y/o arsénico.
Keywords: Gold residues, gold associated with iron and/or arsenic sulfides.
Abstract: There has always been an interest in the retreatment of wastes from old mining operations. During the 70-80's of the 20th century, Scheelite was concentrated and recovered by gravimetric methods from flotation residues, today, the interest is for those that contain gold, rare earths, among others. The old flotation residues of Noche Buena, Melchor Ocampo Zac., totalizing 1.2 Mton with gold and silver concentrations of 3.0 and 40 g / ton, respectively, were characterized and subjected to a metallurgical study to define the process or combination of processes that allows the concentration-extraction of precious metals. Studies with similar materials and the mineralogical characterization suggest an intimate association between gold and sulfides, pyrite or arsenopyrite. The results of this study point towards that a regrind at K80 = 50 microns, followed by a concentration by flotation, enables the recovery of 70-75% of the gold in a bulk pyrite-arsenopyrite concentrate. The separation of the latter, using hydrogen peroxide as oxidant at an ORP of 450 mV and pH of 6.0, produces a pyrite-gold concentrate with a degree of 7.20 g Au / Ton and an overall recovery of 50-55% of the gold in residues. Pyrite-gold association was confirmed by mineralogical characterization on a portion of the bulk pyrite-arsenopyrite gold bearing concentrate, using indirect scanning electron microscopy (SEM), backscattered electrons. Even though, the pyrite-gold association is favorable for concentrate commercialization; arsenopyrite would remain in waste, flotation separation reduces global recovery of gold to only 50%. In case separating is not done, gold recovery will be greater than 70%, however, the arsenic must be recovered and safely confined.
- Enrique Elorza Rodríguez
- Ma. M. Salazar-Hernández
- Ma. del C. Salazar-Hernández
- M. A. Corona-Arroyo