Studies on the liquid-liquid extraction and precipitate flotation of the second kind of Co(II) using 8-hydroxy quinoline

The liquid-liquid extraction and precipitate flotation of the second kind (i.e., without the use of surfactant collectors) have been investigated for Co(II) using 8-hydroxy quinoline (Hq) and the results are compared. Organic solvents used were chloroform in the case of liquid-liquid extraction and ethanol (used as solvent for the collector and as a frothier) in the case of flotation. From the results it appears that liquid-liquid extraction occurs through the formation of the adduct Coq2(Hq) but flotation takes place trough the formation of the precipitate Coq2. Unlike precipitate flotation of the first kind, precipitate flotation of the second kind has the advantage that the recovery is not affected by the ionic strength of the medium. An induction time of about 5 minutes is required to attain the maximum flotation results. The effects of pH and Hq concentration on both of the extraction processes were also investigated and the results are discussed. (author). 45 refs., 8 figs