The galvanic interaction enhanced the flotation separation of chalcopyrite and galena with humic acid as galena depressant

Depression of galena remains a challenge in the flotation separation of the copper/lead sulfide ores. Current technologies still suffer from considerable drawbacks, primarily due to the utilization of numerous hazardous, expensive, and poorly selective inhibitors. In this work, the influence of galvanic interaction between galena and chalcopyrite on their flotation separation with humic acid as galena depressant was investigated using a com-bination of the flotation experiment, minerals dissolution experiment, zeta potential, XPS and electrochemical analysis. The results indicated that the recovery of galena rapidly decreased to 34.7% when the conditioning time was extended to 20 min, which was 50% lower than that without chalcopyrite. The dissolved Pb2+ in the pulp increased by 2.2 times in the presence of chalcopyrite. The galvanic interaction between galena and chalcopyrite enhanced the oxidation of galena, leading to an increase in oxysulfide and hydroxide components on the galena surface. The accelerated oxidation of galena is conducive to the humic acid adsorption, achieving an efficient depression of galena flotation at a short conditioning time. This work demonstrated that enhancing the galvanic interaction between galena and chalcopyrite by extending the conditioning time was a viable and eco-friendly approach to achieve the flotation separation of chalcopyrite and galena with humic acid as a depressant.