four concentrates were collected after cumulative times of 1, 3, 7
and 17 min. After the second concentrate, SIPX collector (4 g/t)
and frother (15 g/t) were added again to the pulp. Flotation was
operated at an air flow rate of 8.0 L/min. The speed of the impeller
was kept constant at 800 rpm. Lime was used to control the pH 9.5
at the end of grinding and during flotation.