Patents

The leach solution containing cadmium, nickel, cobalt and iron solution was subjected to iron removal to precipitate out iron hydroxide and is contacted with a water-immiscible organic solution containing a tertiary amine. The process is particularly useful for the selective extraction to separate cadmium from aqueous solutions containing high total metals content and elevated nickel and cobalt concentrations while avoiding the co-extraction of nickel and cobalt along with the cadmium. The process involves the leaching of spent nickel cadmium battery in the chloride medium and contacting the leach liquor with a water-immiscible organic solution to selectively separate cadmium from nickel and cobalt and produce cadmium loaded organic phase leaving all the nickel and cobalt in the raffinate. The cadmium-loaded organic phase is then contacted with dilute acidic solution to strip out cadmium into the aqueous phase, which could directly be used for the production of different value-added products.