The kinetics of extraction in a novel solvent extraction process with bottom gas injection without moving parts

The extraction kinetics in a novel solvent extraction process have been investigated using the CuSO(4)-H(2)SO(4)-H(2)O-LIX 860-kerosene system. In this process, the liquid-liquid emulsion is generated by bottom gas injection, rather than mechanical stirring. This process has a number of advantages over the mixer-settler unit or the spray column in terms of simple equipment configuration and the ease of cleaning and process control, while providing a sufficiently large interfacial area for mass transfer. The overall rate constant increased with increasing gas injection rate and height of the aqueous phase but decreased with increasing injector diameter. The interfacial area per unit volume of the aqueous phase was estimated from the mean drop size and the dispersed-phase holdup computed from previously established correlations. The variation of the overall rate constant was correlated against a set of dimensionless numbers, representing the operating conditions. Extraction rates and efficiencies comparable to those in a mechanically generated emulsion were attained by this new method. (C) 1998 Elsevier Science B.V. All rights reserved.