Application of a novel mixed anionic/cationic collector in the selective flotation separation of lepidolite and quartz

Abstract

A novel mixed anionic/cationic collector of sodium dodecyl sulfonate (SDS) and cetyltrimethylammonium bromide (CTAB) was applied in the flotation separation of lepidolite from quartz. The micro-flotation experiment proved that the obvious floatability difference between lepidolite and quartz can achieve their flotation separation in this mixed collector system. The optimum dosage of SDS and CTAB were 60 mg/L and 10 mg/L respectively, and the optimal pulp pH was 7.0. Zeta potential analyses showed that the further adsorption of CTAB affects a positive shift of 17.14 mV in the potential of lepidolite after the pre-adsorption of SDS, while quartz shifted positively by only 4.89 mV. Fourier transform infrared analyses indicated that CTAB and SDS can co-adsorb on the surface of lepidolite to enhance its hydrophobicity. X-ray photoelectron spectroscopy analyses further demonstrated that the mixed collector of SDS and CTAB had a stronger selectivity for adsorption on the lepidolite surface than that of quartz. The adsorption strength of SDS on lepidolite was greater than that of quartz, and the co-adsorption of SDS and CTAB on the surface of lepidolite can additionally enlarge their differences in flotation behavior. These may be the essence of achieving the selective separation of the two minerals.