Efficient and selective recovery of Ni, Cu, and Co from low-nickel matte via a hydrometallurgical process

Low-nickel matte was intensively characterized,and Ni,Cu,and Co were determined to exist mainly as(Fe,Ni)_9S_8 and Fe Ni_3,Cu_5FeS_4,and(Fe,Ni)_9S_8 and Fe_3O_4(in isomorphic form),respectively.The efficient and selective extraction of Ni,Cu,and Co from the low-nickel matte in an(NH_4)_2S_2O_8/NH_3·H_2O solution system was studied.The effects of(NH_4)_2S_2O_8 and NH_3·H_2O concentrations,leaching time,and leaching temperature on the metal extraction efficiency were systematically investigated.During the oxidative ammonia leaching process,the metal extraction efficiencies of Ni 81.07%,Cu 93.81%,and Co 71.74% were obtained under the optimal conditions.The relatively low leaching efficiency of Ni was mainly ascribed to Ni Fe alloy deactivation in ammonia solution.By introducing an acid pre-leaching process into the oxidative ammonia leaching process,we achieved the high extraction efficiencies of 98.03%,99.13%,and 85.60% for the valuable metals Ni,Cu,and Co,respectively,from the low-nickel matte.

Low-nickel matte was intensively characterized, and Ni, Cu, and Co were determined to exist mainly as (Fe,Ni)9S8and FeNi3, Cu5FeS4, and (Fe,Ni)9S8and Fe3O4(in isomorphic form), respectively. The efficient and selective extraction of Ni, Cu, and Co from the low-nickel matte in an (NH4)2S2O8/NH3·H2O solution system was studied. The effects of (NH4)2S2O8and NH3·H2O concentrations, leaching time, and leaching temperature on the metal extraction efficiency were systematically investigated. During the oxidative ammonia leaching process, the metal extraction efficiencies of Ni 81.07%, Cu 93.81%, and Co 71.74% were obtained under the optimal conditions. The relatively low leaching efficiency of Ni was mainly ascribed to NiFe alloy deactivation in ammonia solution. By introducing an acid pre-leaching process into the oxidative ammonia leaching process, we achieved the high extraction efficiencies of 98.03%, 99.13%, and 85.60% for the valuable metals Ni, Cu, and Co, respectively, from the low-nickel matte. © 2017, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.