Holos (Aug 2021)
EFFECT OF Ca2+ AND Mg2+ IONS ON THE REVERSE CATIONIC FLOTATION OF ITABIRITIC IRON ORE
Abstract
In this work the effect of the Ca2+ and Mg2+ ions, added as salts of chlorine, on the reverse cationic flotation at pH 10.5 of an itabiritic iron ore sample was evaluated. In general, it was observed that the total ion concentrations higher than 83 mg/L in aqueous solution increased the Fe recovery and SiO2 content in obtained concentrates compared in absence of them. The opposite occurred with Fe content. This effect is due to the electrostatic attraction between the positive species from these ions hydrolysis in aqueous solution and the negative surface of quartz, which avoided the adsorption of the ions aminium, whose main adsorption mechanism is by electrostatic attraction of them with the mineral negative surface. However the use of ethylenediaminetetraacetic acid - EDTA after the ore conditioning with Ca2+ and Mg2+ ions, into adequate proportions of EDTA to total ions, produced concentrates with similar contents of Fe and SiO2 with the concentrates of this sample in absence of ions once they were complexed by EDTA and is no longer adsorbed on negative quartz surface.
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