Hydrodynamic and kinetic characterization of industrial columns in rougher circuit

Abstract: In the present investigation the relationship between collection zone rate constant (k c) and gas dispersion parameters, viz. bubble size (d b), superficial gas velocity (J g), gas hold-up (ε g) and bubble surface area flux (S b) was evaluated. Experiments were conducted in an industrial (4m in diameter and 12m high) and a pilot (0.1m in diameter and 4m high) flotation column in rougher circuit at Miduk copper concentrator in Iran. Gas hold-up was measured using pressure difference technique and mean bubble sizes were estimated from a drift flux analysis. It was found that the collection zone rate constant was not correlated with d b and J g solely but was linearly dependent on ε g and S b for the range of interest. Collection efficiency (E k) and floatability factor (P) in the industrial columns were quantified (E k =3.1%; P =7.7×10−3). The influence of operating parameters comprising superficial gas velocity, slurry solids% and frother dosage/type on S b and flotation kinetics was discussed. Analysis of available industrial data suggested that S b and ε g were related by S b =4.46ε g over the range 30< S b <60s−1 and 7%< ε g <14%. [Copyright &y& Elsevier]