Use of the ionic liquid-tricaprylmethyl ammonium salicylate (TOMAS) as a flotation collector of quartz

•TOMAS, an ionic liquid is used in quartz flotation for the first time.•Flotation recovery of quartz with TOMAS is better than that with DDA.•Consumption of TOMAS is much lesser than DDA.•Adsorption of TOMAS on quartz confirmed by zeta potential, FTIR and XPS.•Molecular modeling supports stronger adsorption of TOMAS with quartz.

Tricaprylmethyl ammonium salicylate (TOMAS), an ionic liquid has been employed as a collector for the flotation of quartz. The sign reversal of zeta potential of quartz from negative to positive values and increase in contact angle from 80 to 700 by the addition of TOMAS have substantiated the interaction of TOMAS with the quartz surface. The change in morphology as indicated in SEM and two peaks at 2933 and 2857 cm−1 owing to the vibrations of CH2 and CH3 as seen in FTIR spectra support the adsorption of the reagent on quartz. The N(1s) peak as observed in the XPS spectra of the quartz treated with TOMAS, and the curve fitting data of C(1s) corroborate the reagent-mineral interaction. A comparative study of adsorption of DDA and TOMAS using classical molecular mechanics also suggests stronger adsorption of the latter on the hydroxylated quartz surface. Flotation studies of quartz at natural pH indicate ∼100% quartz recovery at a TOMAS concentration of 8 * 10−5 M. Flotation of the natural occurring BHQ iron ore containing 38.7% Fe and 43.8% SiO2 concludes that a TOMAS concentration of 3.71 * 10−5 M is sufficient to achieve 67.3% Fe with 66.6% iron recovery. TOMAS stands out as a better quartz collector, when compared with DDA.

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