Low-Temperature Collector for Smithsonite Flotation: Experiments and DFTB+ Study

Smithsonite is an important zinc oxide ore that is mainly recovered through flotation. Previous studies have demonstrated that fatty acid collectors, notably oleic acid, are effective in smithsonite flotation. However, the efficiency of oleic acid is substantially affected by temperature changes. Currently, there is a lack of research on low-temperature collectors for smithsonite flotation. This study aims to determine the flotation recoveries of smithsonite utilizing three novel collectors: sodium lauryl fatty acid amide, dodecyl hydroxamic acid, and 2-ethylhexyl phosphate, as well as the traditional collector, oleic acid. These reagents were examined at various temperatures, dosages, and pH levels using microflotation experiments. The findings indicate that all three of the novel collectors are efficient in recovering smithsonite. Notably, 2-ethylhexyl phosphate can achieve relatively high recovery of smithsonite at low temperatures, which sets it apart from oleic acid. Furthermore, density functional based tight binding (and more) (DFTB+) methods were utilized to disclose the adsorption mechanisms of collectors. Additionally, molecular dynamics simulations were adopted to determine why the use of 2-ethylhexyl phosphate and oleic acid as collectors had different effects on the flotation behaviors of smithsonite at different temperatures. Overall, the results significantly contribute to the understanding of smithsonite flotation at low temperatures.