Testing the k–Sb relationship at the microscale

The proposed relationship between flotation rate constant k and bubble surface area flux Sb for the pulp zone, namely k = PSb, where P is the “floatability factor”, is tested at the microscale. Bubble size Db was measured by an adaptation of the McGill bubble size analyzer. The range in Sb, up to 50 s−1, is comparable to full-scale machines. Standard statistical procedures were used to asses the plausibility of the model for the two materials tested, NiO—20 μm and galena—37 μm giving P ≈ 1.73 × 10−3 and ≈2.82 × 10−3, respectively, comparable to available values. The data, however, cannot unambiguously distinguish among the various relationships of the form k ∝ 1 / D b m where m may range up to 2.