Abstract: The froth features in the batch flotation of a sulphide ore were investigated by using the digital image parameters of the froth, the small number emphasis(N_sne), the average grey level(D_agl) and the instability number(N_ins), under different conditions of impeller speeds and aeration rates. It is found that the value of N_sne is strongly dependent on the average bubble size of the froth and D_agl on the volume fraction of solid in the froth, and the froth features during the batch flotation are influenced by impeller speed and aeration rate. A kinetic model of the concentrate solid flux was developed which relates the flotation process to the image parameters, N_sne and D_agl of the froth  and predictions are well consistent with the experimental data.

Key words:  sulphide ores; batch flotation; small number emphasis; average grey level; instable number