Electrochemical and Spectroscopic Study of Interfacial Interactions between Chalcopyrite and typical Flotation Process Reagents

Urbano Gustavo, Lázaro Isabel, Rodríguez Israel, Reyes Juan Luis, Larios Roxana, Cruz Roel
International Journal of Minerals, Metallurgy and Materials,23(2):127-136. ISSN: 1674-4799, 2016.


Comparative voltammetry and differential double-layer capacitance studies were performed to evaluate the interfacial interactions between chalcopyrite (CuFeS2) and n-isopropyl xanthate (X) in the presence of ammonium bisulfite/39%SO2 and caustic starch under different pH conditions. Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy, measurements of contact angles, and microflotation tests complemented this study and were useful in establishing the type and extent of xanthate adsorption as well as the species involved under different mineral surface conditions. The results demonstrated that the species that favor a greater hydrophobicity of chalcopyrite are primarily CuX and S0, whereas oxides and hydroxides of Cu and Fe as well as an excess of starch decrease its hydrophobicity. A previous conditioning of the mineral surface with ammonium bisulfite/39%SO2 (Separcon®) at pH 6 promoted activation of the surface and enhanced the xanthate adsorption. However, this effect was diminished at pH ≥ 8 and when an excess of starch was added during the preconditioning step.