Heng Zhang , Zhi Lei, Hao Tang, Hao-Ran Wu, Xu-Gang Zhang*, Peng-Fei Xu*
https://doi.org/10.1016/j.mineng.2026.110660
This study addresses the adverse effects of fine serpentine gangue on pyrite flotation, which mainly arise from hetero-aggregation and mechanical entrainment. A novel modular depressant, maleic anhydride-glycol ester-acrylic acid (MAG-AA), was designed by utilizing maleic anhydride as a linker to incorporate selective adsorption groups and aggregation groups into a single molecule. This design enables selective adsorption on serpentine and promotes its flocculation, thereby weakening its adverse effects on pyrite flotation. Flotation test results showed that the pyrite recovery significantly increased and attained 91 % when 4 mg/L MAG-AA was used at a pH 8.5. FTIR results confirmed strong adsorption of MAG-AA on serpentine. Analyses of zeta potential, XPS, and SEM-EDS further demonstrated that COO⁻ groups in MAG-AA chemically interact with the serpentine surface, causing a shift in its surface charge to a more negative state and suppressing hetero-aggregation with pyrite. In addition, microscopy and sedimentation tests have revealed that MAG-AA effectively induces serpentine aggregation due to its structural flocculation groups. Therefore, MAG-AA simultaneously achieves selective depression and flocculation of serpentine, which reduces both surface contamination and entrainment, thereby enabling effective pyrite-serpentine separation.