Adsorption studies of smithsonite flotation using dodecylamine and oleic acid

Abstract

The interaction of various concentrations of sodium sulfide, dodecylamine (DDA) and oleic acid (OA) on smithsonite were investigated at different pH levels using zeta potential, contact angle, microflotation and diffuse-reflectance FT-IR studies. Flotation results show that the recovery and contact angle are enhanced to 94% and 115°, respectively, with a dodecylamine concentration of 1.6 × 10t−3 M and a pH of 11.5. The optimum sodium sulfide consumption was found to be 2.6 × 10−2 M. Zeta potential measurements showed less negative charge after DDA treatment on the surface of pure crystalline smithsonite. The recovery and contact angle for oleic acid flotation rises to 93% and 105°, respectively, with an oleic acid concentration of 1.1 × 10−3 M and a pH of 10. The zeta potential in the case of using oleic acid showed a more negative charge after oleic acid treatment on the smithsonite surface. The FT-IR spectra studies of smithsonite conditioned with DDA confirmed the adsorption of DDA on the smithsonite surface. The spectra show that the mineral surface is changed partially to a ZnS layer after sodium sulfide treatment. The spectra confirmed the formation of zinc oleate on the smithsonite surface after oleic acid treatment. A comparison of the results using cationic and anionic collectors showed that the different adsorption densities of the reagents in two cases conferred different degrees of hydrophobicity on the smithsonite surface.