Effects of surfactants combination on iron ore flotation

Abstract

Frothing plays a crucial role in mineral froth flotation. However, the use of only frothing reagents is not common in the reverse cationic flotation of iron ores because etheramines, the commonly applied collectors, also play this role. In alkaline aqueous solution, etheramines dissociate as ionic (collector) and molecular (frother) species, simplifying the chemical system. Despite practical and functional, this practice is limited once etheramines are less efficient to form foam and more expensive than conventional frothers, e.g., alcohols and polyglycols. This study investigated the comparative effects between non-ionic frothers and cationic etheramines on foam properties in two phase systems, and the combination of these etheramines and frothers in three phase systems in comparison to single etheramines and their mixtures. The results show that the frothers DF1012 and MIBC produce smaller bubbles and more stable foams than the single ethermonoamine or etherdiamine. The partial replacement of etheramines by non-ionic frothers reduced the silica content in the concentrate, improving flotation selectivity at specific mixture condition of collector substitution for each frother type, despite decreasing the iron metallurgical recovery. The substitution of etherdiamine by polyglycol at 10 % w/w produced the best result in the cationic/non-ionic surfactants comparison, although the mixture of etherdiamine and ethermonoamine yielded the highest selectivity, because of the synergistic effect on froth stability and mineral surface adsorption.