Flotation behavior and co-adsorption essence of combined SBX/MBT collectors to sulfidized azurite

Combined collectors are widely used in mineral flotation. However, in the field of copper oxide mineral flotation, theoretical research on combined collectors is relatively scarce, especially the combination of chelating agents and xanthates. Herein, this study systematically investigated the flotation performance and related potential adsorption chemical essence of sodium butyl xanthate (SBX), 2-mercaptobenzothiazole (MBT), and their combined collectors on sulfidized azurite. Micro-flotation results demonstrated that the low-dosage combination collector system of SBX/MBT can effectively improve the flotation recovery of sulfidized azurite. Surface tension results indicated that the combined collectors had higher surface activity than the single collector, thus exhibiting better foam stability. LEIS, SEM-EDS and contact angles analysis demonstrated that compared with single collector, the combined collectors could adsorb more uniformly on the surface of sulfidized azurite, effectively improving its hydrophobicity. ToF-SIMS and XPS further demonstrated that MBT adsorbed on azurite by bonding its S and N atoms with Cu atoms of sulfidized azurite to form the surface MBT-Cu complexes. Combined with the results of adsorption capacity tests, further analysis indicated that the combined collectors of SBX and MBT may have achieved co-adsorption by forming a mixed-ligand complex on the surface of sulfidized azurite, which enhanced the adsorption density and stability of the collector on the surface of sulfidized azurite.