Flotation tests of individual minerals and artificially mixed min-
erals were both conducted. Flotation tests were carried out in a
mechanical agitation flotation machine (Fig. 2). The volume of
the cell is 50 ml. The mineral suspension was prepared by adding
2 g of minerals to 40 ml of solutions. The pH of the mineral suspen-
sion was adjusted to a desired value by adding NaOH or HCl stock
solutions. The prepared acidified sodium silicate and sodium oleate
solution was added at a desired concentration and conditioned for
3 min. Each flotation test was carried out for a total of 4 min.