Selective depression of 2-mercapto-4-(4-pyridyl) thiazole in the separation of chalcopyrite and molybdenite: mechanism study and computational simulation

Due to the similar natural floatability of chalcopyrite and molybdenite, the efficient separation of the two has attracted much attention. In this study, 2-mercapto-4-(4-pyridyl) thiazole (MPT) was selected as a chalcopyrite inhibitor for copper-molybdenum separation. The results of single mineral flotation showed that when pH = 9 ± 0.2 and the dosage of MPT was 50 mg/L, the recovery difference between the two minerals was as high as 84.75 percentage points, showing good selectivity. The contact angle test and molecular dynamics simulation show that MPT can significantly enhance the hydrophilicity of chalcopyrite surface. ToF-SIMS and LEIS analyses showed that MPT was mainly adsorbed on the surface of chalcopyrite. Further XPS analysis and DFT calculations show that the thiol group in MPT forms a Cu-S chemical bond with the Cu active site on the surface of chalcopyrite, which is the main reason for its selective adsorption and depression of chalcopyrite flotation. The results not only reveal the mechanism of MPT, but also provide a theoretical reference for the development of new copper-molybdenum separation inhibitors.