Elimination of Ferric Ion Effect on Separation between Kyanite and Quartz Using Citric Acid as Regulator

Ferric ions produced during grinding influence the flotation separation between kyanite and quartz adversely. In this study, citric acid was used as a regulator to eliminate the effect of ferric ions on the separation of kyanite from quartz with sodium oleate (NaOL) as a collector. The microflotation test results indicated that the quartz was selectively activated by FeCl3and maintained significant quartz recovery. However, the citric acid could selectively eliminate the effect of ferric ions on the quartz and minimally influenced the kyanite. Contact angle tests demonstrated that FeCl3significantly increased the interaction between NaOL and quartz, resulting in the high hydrophobicity of quartz, and the addition of citric acid made the quartz surface hydrophilic again but slightly influenced the kyanite. Fourier-transform infrared spectroscopy showed that FeCl3facilitated NaOL adsorption onto the quartz surface, and the addition of citric acid eliminated the activation of FeCl3on the quartz, resulting in the nonadsorption of NaOL onto the quartz surface. However, the FeCl3and citric acid exhibited a negligible effect on NaOL adsorption onto the kyanite surface. X-ray photoelectron spectroscopy analysis indicated that the citric acid eliminated FeCl3activation on the quartz.Keywords:kyanite;quartz;citric acid;ferric ion;selective elimination