The extraction and separation of copper and nickel in ammoniacal chloride media were studied using the mixed extractants containing of LIX841 and Aliquat336. The separation efficiency of Cu/Ni has been discussed under different concentration ratios of L1X841 and Aliquat336, aqueous pH values, concentrations of total ammonia and chloride in aqueous phase. The results indicate that the addition of Aliquat336 into L1X841 induces an antagonistic effect on the extraction reaction, especially for nickel. Nonetheless, an evident improvement of separation efficiency of copper over nickel can be found under the low concentration ratio of Aliquat336. The efficient separation of Cu/Ni also can be achieved by adjusting the aqueous pH and the concentration of ammonia and chloride. At the pH range of 7-11, the separation efficiency for the mixed extractant system is superior to that for L1X841 system. The low concentrations of chloride and ammonia in the aqueous phase are favorable to the extraction and separation of Cu/Ni. (C) 2013 Elsevier B.V. All rights reserved.