The role of Na2S2O5 and activated carbon on the selective flotation of chalcopyrite from a copper ore using a dithiophosphine-type collector

This article presents the results of an investigation into the effects of sodium meta bi-sulphite (Na2S2O5) and activated carbon on the selective flotation of chalcopyrite from pyrite. In Kure Copper Concentrator, a chalcopyrite concentrate is produced with around 17.5% Cu content using lime as a depressant. Flotation tests conducted in this investigation employ Na2S2O5 and activated carbon as regulating reagents and reveal that Cu grades up to 28% could easily be achieved. The deactivation mechanism of S2O52- may be similar to that of SO32- such that the decomposition of the collector and/or oxidized surface species may be effective on selectivity. Activated carbon removes collector species from the pulp, creating collectorless flotation conditions. Conditioning time is an important parameter on selectivity and decreases the dosage of Na2S2O5 used.