Flotation separation of dravite from phlogopite using a combination of anionic/nonionic surfactants

In the present study, the effect of a mixture of anionic collector (sodium oleate)/ non-ionic surfactant (sorbitan monooleate) on the flotation separation of dravite from the main associated gangue phlogopite was investigated in comparison of using single sodium oleate as a collector. The flotation experiments were conducted on pure single minerals of dravite and phlogopite. The flotation results demonstrated that adding sorbitan monooleate to Na-oleate at a dose of 5.64 kg/Mg Na-oleate with 0.43 kg/Mg sorbitan monooleate in the presence of methyl isobutyl carbinol (MIBC) as a frother (0.12 Kg/Mg) at pH 7.7 improved the flotation efficiency of dravite from 73.5% by using sodium oleate as a single collector to 96.9% using the mixture. Whereas, the flotation recovery of phlogopite in the same conditions reached 26.3%. The zeta potential measurements and Fourier transform infrared (FTIR) spectroscopy analysis were also implemented to investigate and predict the mechanism of collector adsorption on the mineral surfaces. As a result of flotation experiments and the zeta potential measurements of FTIR analysis, high chemisorption of the mixed collector on the surface of dravite was obtained, on the contrary, a little amount of the collector mixture adsorbed on the phlogopite surface.