MINERALOGY AND FLOTATION OF RARE-EARTH-BEARING BARIUM FLUOROPHLOGOPITE

In iron-making processes with rare-earth-containing iron ores as feeds , the rare-earth oxides report to slags. While most rare-earth oxides in the slags can be recovered by a combination of high intensity magne tic separation with gravity separation processes, europium and scandiu m remain in tailings of the slag mineral separation process. Crystal s tructure and chemical composition of the europium and scandium-bearing ''mineral'' in the slags have been determined by X-ray diffraction an d electron microprobe analyses. This ''mineral'' was identified as rar e-earth-bearing barium fluorophlogopite (REBF). Flotation experiments were conducted to investigate the flotation behaviors of the REBF. Exp erimental results show that the REBF can be collected by using dodecyl ammonium acetate, sodium oleate or a combination of both in an appropr iate proportion and sequence. The flotation reaction of the REBF with the collectors was discussed with the help of infrared spectra and ele ctrokinetic measurements. Physical adsorption of the cationic collecto r and chemical adsorption of the anionic collector on the surface of t he negatively charged REBF were observed. Synergistic effect is signif icant when addition of sodium oleate is followed by addition of dodecy lammonium acetate during flotation.