The present study deals with the applicability of a precipitation method for the differential separation of Cd-CN and Zn-CN complexes in synthesized waste water. In order to separate cadmium from zinc in synthesized waste cyanide water by the precipitation method, it was necessary to decompose the metal cyanide complexes prior to the precipitation treatment. From a series of tests, it was found that the pretreatment by the addition of sodium sulphide was effective for the selective precipitation of the Cd-CN complexes. On the other hand, the Zn-CN complexes were decomposed by the pretreatment of hydrogen peroxide, and then the zinc and cyanide ions were simultaneously precipitated by this method. This method being applied, it was found that the differential separation of the constituting metals was effectively achieved by this method
