Kinetics and Hydrodynamics of Silver Ion Flotation

This paper studies and determines the dispersion properties (Jg, Eg and Db), kinetics parameters and hydrodynamics of the process and its effect on the recovery of silver contained in spent diluted fixers by techniques of ion flotation in columns. The experimental results show silver recoveries of 97 % using sodium isopropyl xanthate (SIX) 0.06 g.L-1 and 0.04 g.L-1 of frother, at a Jg of 1.0 cm.s(-1) and Jl of 0.72 cm.s(-1). Xanthate-promoter combinations do not improve the separation; however, recoveries of 91.5% are achieved. The control of pH at 6.0 during the ion flotation of silver helps to improve the separation, compared to pH values of 7.0 and 8.0. The kinetic constant of apparent flotation k (min(-1)) maintains a linear behavior with the recovery and the dispersion properties, until reaching a slope change in the plot of Eg Vs Jg, where the system changes bubble flow regime, from homogeneous to turbulent.