Effect of Long-Term Stockpiling on Oxidation and Flotation Response of Low-Grade Copper Sulphide Ore

Since the start-up of Sossego copper concentrator, located in Carajás Mineral Province southeast Para State, Brazil, low-grade ore (~0.34% Cu) has been stockpiled, as defined long-term mine plan, to be reclaimed at end life. Given this imminent need process around 40 Mt ore, questions have raised related extent oxidation that might occurred stockpiled ore. In context, a study was designed characterize and assess effect on its flotation response. A sampling campaign carried out analyze main variables could influence level oxidation, and, consequently, recovery, such stockpiling time, depth, particle size. The results showed there are two factors negatively impacting recovery ore: surface liberation mineral. Depth period were not found nor An empirical model proposed for rougher stage, which resulted predicted value 90.7%, lower than fresh (and higher content) fed plant (93%).