Co-adsorption mechanism of isoamyl potassium xanthate and ammonium dibutyl dithiophosphate on sulfidized smithsonite in dodecylamine flotation system

The flotation research of zinc oxide ores has been paid more and more attention with the increasing demand for zinc resources. In this particular study, micro-flotation tests were carried out using a mixed ternary collector comprising dodecylamine (DDA), potassium isoamyl xanthate (KAX), and ammonium dibutyl dithiophosphate (ADD), along with pre-sulfidization treatment using Na2S to improve the flotation efficiency of smithsonite. Micro-flotation experimental results showed that the flotation recovery significantly increased by over 40 % when employing the ternary mixed collector of DDA-KAX-ADD, as compared to using DDA alone. Through the measurement of the adsorption and surface potential of each collector on the mineral surface, the synergistic effect of DDA, KAX, and ADD was confirmed. The phenomenon was discovered that the ternary collector effectively reduced the solution's surface tension in the surface tension tests, which enhanced the adsorption efficiency of ternary collector on mineral surface. Additionally, the verification of the chemisorption and physisorption between the ternary collector and the mineral surface was accomplished through the utilization of X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The measurement results of contact angles demonstrated that the ternary collector significantly enhanced the hydrophobicity of sulfidized smithsonite, a finding that was further supported by molecular dynamics (MD) simulation. Finally, the MD simulation revealed that DDA, KAX, and ADD exhibit multilayer adsorption on the mineral surface.