Depression Effect of Thioglycolic Acid (TGA) on Flotation Separation of Molybdenite from Copper Sulfides with different Collectors: An Experimental and Theoretical Study

In the present study, the depression effect of thioglycolic acid (TGA) on chalcopyrite and pyrite in the presence of different collectors, including potassium ethyl xanthate (PEX), sodium isopropyl xanthate (SIPX), and mercaptobenzothiazole (MBT) in the flotation separation of molybdenite from copper and iron sulfide minerals was evaluated by micro-flotation and bench-scale flotation experiments. Surface characterization and adsorption mechanism were investigated by the density functional theory (DFT) method. The flotation experiment results demonstrated that the depression effect of TGA depends on the type of collector applied in the previous stages. DFT calculation provided strong evidence for the results of experiments. It was found that both chalcopyrite and pyrite were effectively depressed in the selective flotation of molybdenite from copper and iron sulfides by TGA when PEX was used as the collector in the bulk flotation stage. It was also found that the use of MBT causes effective flotation of chalcopyrite and molybdenite in the bulk flotation stage, however, its removal from the mineral surface by TGA was not as convenient as PEX.