Selective Depression and Adsorption of a Novel Eco-Friendly Depressant on the Flotation Separation of Chalcopyrite from Carrollite

Carrollite is often associated with chalcopyrite, and their natural floatability is similar, which makes it difficult to separate the two minerals by flotation in industrial production. In this study, the depression behavior and mechanism of flaxseed gum (FG) introduced as carrollite depressant on carrollite and chalcopyrite in PBX flotation system was investigated through micro-flotation, zeta potential, total organic carbon (TOC), fourier transform infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS). The flotation results indicated that FG was a highly effective depressant to separate 92.39% chalcopyrite from the mixture with carrollite at pH 9.0 with a reagent scheme of 50mg/L of FG and 8.0 × 10-5mol/L of PBX. The zeta potential and TOC analysis results demonstrated that both carrollite and chalcopyrite exhibited a favorable affinity to FG, and pre-treated FG significantly hindered the adsorption of PBX on carrollite, while only slightly decreased that on chalcopyrite, resulting in the considerable difference in floatability between carrollite and chalcopyrite. In addition, FT-IR spectra and XPS detection results further confirmed that the affinity of FG towards carrollite superior to PBX might be due to the bidentate coordination of the carboxyl groups in FG with Co sites on carrollite surface, whereas the interaction between its carboxyl groups and Cu sites on both minerals was very weak or did not happen. Therefore, FG was promising in flotation separation of copper-cobalt sulfide minerals as a new friendly efficient depressant.