Mineralogy and flotation of rare-earth-bearing barium fluorophlogopite

Abstract

In iron-making processes with rare-earth-containing iron ores as feeds, therare-earth oxides report to slags. While most rare-earth oxides in the slags can be recovered by a combination of high intensity magnetic separation with gravity separation processes, europium and scandium remain in tailings of the slag mineral separation process. Crystal structure and chemical composition of the europium and scandium-bearing “mineral” in the slags have been determined by X-ray diffraction and electron microprobe analyses. This “mineral” was identified as rare-earth-bearing barium fluorophlogopite (REBF). Flotation experiments were conducted to investigate the flotation behaviors of the REBF. Experimental results show that the REBF can be collected by using dodecylammonium acetate, sodium oleate or a combination of both in an appropriate proportion and sequence. The flotation reaction of the REBF with the collectors was discussed with the help of infrared spectra and electrokinetic measurements. Physical adsorption of the cationic collector and chemical adsorption of the anionic collector on the surface of the negatively charged REBF were observed. Synergistic effect is significant when addition of sodium oleate is followed by addition of dodecylammonium acetate during flotation.