Depression effect of Al(Ⅲ) and Fe(Ⅲ) on rutile flotation using dodecylamine polyxyethylene ether as collector

Few literatures pay emphasis on investigating the effect brought out by metal ions on flotation in the case of cationic collector. In this work, the effect of Al(Ⅲ) and Fe(Ⅲ) on rutile floatability using dodecylamine polyxyethylene ether (AC1203) as collector was evaluated. In addition to the flotation tests, zeta potential measurements, solution chemistry calculation, surface tension measurement and XPS analysis were conducted to elucidate the detailed depression mechanism. The results indicate that the floatability of rutile seriously inhibited by Al(Ⅲ) and Fe(Ⅲ), and the depression effect of Al(Ⅲ) is much stronger than that of Fe(Ⅲ). Moreover, on the basis of zeta potential and solution chemistry calculation tests, Al(OH)3 and Fe(OH)3 precipitates are believed to be the principal components that act with rutile surface, and the preferential adsorption of Al(OH)3 precipitate could further deteriorate the interaction of collector with rutile. It is worth mentioning that Al(Ⅲ) and Fe(Ⅲ) are capable of acting with AC1203 to form complexes, consequently affecting the flotation environment. Furthermore, XPS analysis reveals that Fe(OH)3 precipitate tend to adsorb on rutile surface through physical interaction, while Al(OH)3 precipitate could react with Os and bridging O on rutile surface to form Ti-O-Al bonds, resulting in less active Ti sites for collector adsorption.