Effect of the amine ether type on the quartz hydrophobicity in the reverse cationic flotation process of iron ore

The cationic reverse flotation route is one of the main processes to remove quartz from iron ore. The ether amines are the most common surfactant used to modify quartz's surface hydrophobicity. Beyond the traditional differentiation between ether monoamines and ether diamines, these reagents may have other differences as raw materials' source, carbon chain length and type and neutralization degree. The definition of the best ether amine for a given iron ore is commonly performed through empirical testwork only. The pKa value (pH where collector's molecular and ionic species have equal concentration) for different ether amine types where determined and quartz flotability was investigated at different pH conditions, different collector concentration and type, in the presence and absence of an iron minerals depressant. The effect of carbon chain length and differences between ether monoamines and ether diamines for quartz flotability were clarified for distinct flotation conditions. (author)