Advancing green flotation: Separation of Cu-Pb minerals through the application of eco-friendly organic double reaction group depressant

Achieving efficient flotation separation of chalcopyrite and galena while maintaining environmental friendliness poses a challenge. This study utilized the environmentally friendly copolymer acrylic acid-2-acrylamide-2-methylpropanesulfonic acid (AA/AMPS) as a depressant to separate chalcopyrite and galena. Flotation tests revealed a significant reduction in galena recovery when AA/AMPS was employed, with minimal impact observed on chalcopyrite. In artificial mixed ore flotation, AA/AMPS was found to enhance the efficiency of copper and lead separation, surpassing K₂Cr₂O₇. Furthermore, the effectiveness of AA/AMPS in facilitating copper-lead separation has been validated in practical ore flotation. The presence of AA/AMPS inhibited the adsorption of SBX onto galena, as confirmed by zeta potential and contact angle measurements. However, the adsorption on chalcopyrite remained unaffected. Through analyses using Atomic Force Microscope, X-ray photoelectron spectroscopy, and Density Functional Theory, a robust chemical interaction between the reactive groups in AA/AMPS and Pb sites on galena was uncovered, resulting in the formation of a hydrophilic polymer layer. This layer impedes SBX adsorption and reduces galena’s floatability. In contrast, no significant chemical adsorption was observed between AA/AMPS and Cu and Fe sites on chalcopyrite, preserving its SBX affinity. Overall, AA/AMPS shows promise in replacing traditional depressants for Cu-Pb sulfide ore separation, enhancing environmental sustainability.