Reverse cationic flotation of iron ore by amide-amine: bench studies

Abstract

This study evaluated the performance of a new collector amide-amine compared with a traditional etheramine in conventional reverse cationic flotation of a siliceous itabirite sample of the Quadrilátero Ferrífero (d80 = 116 μm, 40% Fe and 41.2% SiO2). Statistical design of experiments was used to determine the influence of pH, collector and starch dosages on mass and Fe recoveries, Fe and SiO2 grade in the concentrate, Fe grade in the tailings and Gaudin's selectivity index (S.I). For the amide-amine, starch had no significant effect on mass recovery and in the Fe and SiO2 grade in the concentrate. For the same dosages, it was found that amide-amine was less selective than etheramine. However, at higher dosages, at pH 8 and without starch, concentrates with Fe >65% and SiO2 <5% grades were obtained, similar to the grades obtained with etheramine and starch at pH 10.5. The mass and Fe recoveries were higher and consequently, the Fe grades in the tailings were lower. These results indicate that, despite the higher dosage required, amide-amine is selective without starch, which is very interesting from the economic point of view and simplification of the process route, implying a great potential for its industrial application.