Effects of frothers on bubbles size and flotation performance of hydrophobic minerals

Abstract

Frothers facilitate the reduction of bubbles size by preventing bubbles coalescence and produce more stable froths. The collision probability of the bubbles and particles substantially increases by decreasing bubble size. For the same volume system, fewer bubbles result from a distribution of large-sized bubbles, and more bubbles result from a distribution of small-sized bubbles. In this research, fundamental two-phase frother characterization parameters were aimed to link with three-phase coal and talc flotation behavior. For this purpose, the effect of single and dual frother systems on inhibiting bubble coalescence was investigated with methyl isobutyl carbinol (MIBC), isooctanol (2 ethyl hexanol), pine oil, and Dowfroth 250. Based on the results of single frothers, isooctanol at the lowest critical coalescence concentration (CCC) value of 6×10⁻⁶ achieved the smallest bubbles with Sauter mean diameter of 0.80 mm. By blending Dowfroth 250 and pine oil, the bubbles size decreased significantly, reaching 0.45 mm. While the highest recoveries in coal flotation were obtained in single and frother blends where the bubbles size was measured as the smallest in two-phase system, and such a relationship was not found for talc flotation.