Recovery of Cu and Ni from a Secondary Resource by Hydrometallurgical Route

A high iron containing copper and nickel based secondary resource analysing 22.43% Cu, 7.94% Ni and 36.28% iron has been treated to recover valuable metals by leaching with sulphuric acid. It was found that recovery of copper and nickel increased with increase in temperature and sulphuric acid concentration and in a two-stage leaching with 20% (v/v) sulphuric acid at 368 K above 99.9% copper and 82.35% nickel were recovered. The leaching data best fitted into chemical controlled kinetic model showing chemical reaction at the surface of the solid matrix. Activation energy of 20 kJ/mol and 44 kJ/mol were acquired for dissolution of copper and nickel, respectively. Attempts were also made to separate iron from the leach liquor by using Versatic 10 and recovery of copper and nickel in the form of their sulphate by solvent extraction; the copper and nickel could then be recovered as salts, metal cathodes or metal powder.