Selective flotation separation of spodumene from feldspar using mixed anionic/nonionic collector

In the paper, the effect of a new type of mixed anionic/nonionic collector sodium oleate (NaOL) / dodecyl succinimide (DS) on the flotation of spodumene from feldspar was investigated, compared to single collector NaOL and DS. The micro-flotation was conducted on single minerals and artificial mixed minerals with single and mixed collector. Micro-flotation results show that the mixed collector at the NaOL: DS molar ratio of 4:1 at pH 8.5 exhibit the highest flotation separation performance. Zeta potential measurements, Fourier transform infrared (FTIR) spectroscopy and pyrene fluorescence measurements were used to investigate possible adsorption mechanism of mixed collectors NaOL/DS on spodumene and feldspar. FTIR and Zeta potential measurements results show the high adsorption density of mixed collector NaOL/DS on the surface of spodumene, while only a small amount of them are adsorbed on the feldspar surface. The result of pyrene fluorescence spectroscopy analysis reveal that the critical micelle concentration (CMC) value and polarity of mixed collector NaOL/DS is lower than that of corresponding single surfactant NaOL and DS, making it easier to form micelles. These results imply that the mixed collector NaOL/DS can generate superior synergistic effect and achieve better separation performance than either of its components alone.