Mass transfer and hydrodynamic characteristics of the Denver type of flotation cells

Abstract

The rates of gas induction Q, effective interfacial area a, and liquid-side mass transfer coefficient k_La were obtained from 100 × 100, 140 × 140, 172 × 172 and 380 × 380 mm × mm Denver-type flotation cells. The rates of gas induction were measured by a soap-film meter and values of a and k_La were obtained by chemical methods. The effects of impeller speed, liquid submergence and the presence of fine solid particles on the values of Q, a and k_La were investigated. Further, the effects of liquid viscosity and ionic strength on Q were studied. The performance of the Denver type of flotation cells is compared with the conventional mechanically agitated contactors and other gas-inducing types of agitated contactors. Scale-up criteria are discussed.