SILVER RECOVERY FROM AQUEOUS STREAMS USING ION FLOTATION

lon flotation was examined as an alternative method for the recovery o f silver from dilute aqueous solutions containing complexing agents (t hiosulphates). The dispersed-air flotation technique (laboratory micro -scale) was used for bubble generation, while the flotation experiment s were performed using the cationic surfactant dodecylamine, (ethanol or water solutions); as a convenient frother, ethanol (0.5% v/v) was a lso added in most experiments. The main physicochemical parameters inf luencing the process, such as pH of the solution, concentrations of su rfactant, of thiosulphate and of silver, as well as kinetic parameters , such as flotation time and gas f70wrate, were evaluated Employing th e optimum defined conditions, high recovery of silver (approaching 100 %) was obtained. The application of the proposed method for the treatm ent of spent solutions, generated after the development of X-rayed fil ms, has also been examined.