Abstract: To address the challenges in separating copper-lead sulfide minerals and the high toxicity and severe pollution associated with traditional dichromate inhibitors,a novel eco-friendly organic depressant(ZJ201) for galena was developed through molecular design.The separation performance of ZJ201 was systematically evaluated through flotation tests on pure minerals,artificially mixed minerals,and closed-circuit tests on real ore.The mechanism of action was elucidated using contact angle measurement,Zeta potential analysis,Fourier transform infrared spectroscopy (FTIR),and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS).The results indicated that within the pH range of 4 to 7,ZJ201 could selec tively and strongly depress galena while minimally affecting the floatability of chalcopyrite.At pH=6 with a ZJ201 dosage of 2 mg/L,the recovery of galena was reduced to below 2.5%,while the recovery of chalcopyrite remained above 90%.Closed-cir cuit tests on real ore yielded a copper concentrate with a Cu grade of 32.34%,Pb content of 1.66%,and Cu recovery of 98.56%,as well as a lead concentrate with a Pb grade of 67.14%,Cu content of 0.049%,and Pb recovery of 99.74%,dem onstrating excellent separation efficiency.Mechanism studies revealed that ZJ201 preferentially and chemically adsorbs onto the galena surface via its phosphate and hydroxyl functional groups,significantly enhancing its hydrophilicity,thereby achieving ef ficient and selective separation of chalcopyrite from galena.

Key words: eco-friendly depressant,copper-lead separation,depression mechanism,Zeta potential,adsorption