| Abstract: | The leaching behaviour of Ag in NH_3-O_2 and NH_3-H_2O_2 aqueous solutions was investigated. The results show that the dissolution of Ag was restrained by forming of a silver suboxide film on the surface under low oxidant concentration and atmospheric pressure conditions (e.g., in NH_3-O_2-H_2O system); when the concentration of oxidant was high enough (e.g., in NH_3-H_2O_2-H_2O system), the leaching process was carried out without forming of the film and the rate of dissolution of Ag was controlled by a step of mass transfer. Based on experimental results, a reaction mechanism of oxidation leaching of Ag in ammoniacal solutions was discussed. |
