Enhancement of spodumene flotation behavior and activation mechanism via Cu(II)/PMS advanced oxidation processes

Spodumene is often associated with quartz in ore deposits. Due to their similar physicochemical properties, achieving selective flotation separation using sodium oleate (NaOL) alone is challenging. This study proposes an innovative reagent scheme for selectively separating spodumene from quartz via flotation. The approach employs a Cu(II)/peroxymonosulfate (PMS) advanced oxidation process to activate the spodumene surface, which subsequently promotes the adsorption of NaOL as the collector. Single-mineral flotation tests demonstrated that under the conditions of pH 8, NaOL concentration of 8 × 10 −4  mol/L, Cu(II):PMS molar ratio of 3:1, and total Cu(II)/PMS concentration of 3 × 10 −4  mol/L, the recovery of spodumene reached 93.48%, while that of quartz was only 0.91%. Artificial mixed mineral flotation tests yielded a spodumene concentrate with a Li 2 O grade of 6.52% and a recovery of 83.46%. The activation mechanism was investigated using zeta potential, contact angle, Fourier transform infrared spectroscopy (FTIR), electron paramagnetic resonance (EPR), scanning electron microscopy with energy dispersive spectroscopy (SEM), and X-ray photoelectron spectroscopy (XPS) analyses. The results indicate that OH generated by the Cu(II)/PMS system is associated with cleaning of the spodumene surface and modification of its chemical environment, which in turn correlates with enhanced NaOL adsorption and increased surface hydrophobicity. These observations are consistent with the improved flotation separation of spodumene from quartz under the tested conditions. This study presents a promising activation strategy for the efficient flotation of spodumene.