Effect of dissolved fluorite and barite species on the flotation and adsorption behavior of bastnaesite

The flotation of rare earth minerals, which is of current interest in the mineral processing field, is challenging owing to the dissolution of gangue minerals. In this study, dissolved fluorite and barite species were found to significantly affect the flotation behavior of bastnaesite. The mechanism was investigated using microflotation tests, zeta potential measurements, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and solution chemistry analysis. The microflotation results confirmed that the presence of gangue supernatants significantly reduces the recovery of bastnaesite during flotation with sodium oleate as a collector. The zeta potential and solution chemistry analyses showed that the supernatant species can adsorb onto the bastnaesite surface by forming hydroxy and carbonate compounds, thus affecting the zeta potential value and reducing the adsorption of oleate species. The FTIR analysis suggested that treatment with supernatants weakens the adsorption of oleate species, and that Ca/Ba-oleate complexes are adsorbed on the bastnaesite surface. The XPS analysis confirmed that lattice ions from the gangue minerals adsorb/precipitate on the bastnaesite surface, hindering the chemisorption of oleate species and thus decreasing the floatability of bastnaesite.