The selective adsorption and flotation separation of spodumene from feldspar using a novel iron-group multiple ligand collector

Abstract

Spodumene and feldspar have little difference in flotability due to their similar crystal chemistry properties. Fe-octyl hydroxamic acid (OHA) (iron complexes of octyl hydroxamic acid) demonstrates excellent selectivity but restricted collecting performance in spodumene flotation. In this work, we added sodium dodecyl sulfate (SDS) into Fe-OHA to obtain a novel multiple ligand collector, which was named Fe-OHA-SDS to enhance the collection ability of Fe-OHA. The efficient separation of spodumene from feldspar (the recovery difference was about 84 %) was achieved by Fe-OHA-SDS without adding depressants and foaming agents at pH 6.2. The separation mechanisms were explored by Zeta potential, contact angle, in-situ microcalorimetric, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) measurements. The findings revealed that Fe-OHA-SDS was more easily bonded to the spodumene surface than the feldspar surface. Meanwhile, the adsorption of Fe-OHA-SDS significantly expanded the hydrophobicity differences on these two mineral surfaces. The Fe-OHA-SDS was adsorbed on the spodumene surface through the Fe-O bond, which differed from the interaction mechanism of traditional mixed collectors on mineral surfaces. Therefore, Fe-OHA-SDS was an efficient collector with potential application value in spodumene flotation.