In this investigation the froth zone of an industrial column (4 m "diameter" x 12 m "height") in rougher circuit was characterized. Experiments were carried out at Miduk copper concentrator, Iran. Miduk is a unique copper processing plant which utilizes columns in rougher circuit. Cleaning and selectivity actions in the rougher froth were illustrated using solids and grade profiles along with RTD data. The impact of froth depth (FD) on overall rate constant (k) and k-S(b) relationship was evaluated. Dependency of overall flotation kinetics on froth depth and gas velocity (J(g))was modeled by k = 4.97(FD)(-0.87) (J(g))(0.80). Froth recovery (R(f)) was estimated and modeled in terms of froth residence time of slurry (FRT(Slurry)) as R(f) = R(f.max)exp(-k x FRT(Slurry)). Finally, the correlation between k, S(b) (indicative of the collection zone performance) and FRT(Slurry) (indicative of the froth zone performance) was modeled by k = 0.02 (FRT(Slurry))(-0.62)(S(b))(0.82). (C) 2008 Elsevier Ltd. All rights reserved.