Study on innovative process of leaching of chalcopyrite.

The process and mechanism were studied of the leaching of chalcopyrite with ammonium persulphate in the presence of Ag ions as catalyst. The results showed that Cu recovery of more than 98% was obtained using an initial concentration of ammonium persuphate of 0.50 mol/l, leaching temperature of 368 K, leaching time of 100 minutes, chalcopyrite particle size of - 74 + 58 micrometres, Ag ion concentration of 0.001 mol/l, stirring speed up to 600 r/min and pulp density of 25 g/l. Characterisation of the leach residues showed that the silver ions had become uniformly distributed as silver sulphide and that elemental S was produced during the leach and was also uniformly distributed in the residues. Pyrite in the original concentrate was retained in the residues, indicating that it was not oxidised and leached with ammonium persulphate. The analysis suggests silver ions react with chalcopyrite to produce silver sulphide which is mixed with the sulphur layer on the product. This reaction strongly enhances the conducting behaviour of the sulphur layer on the chalcopyrite and is a key factor in accelerating the Cu leaching rate.
The process and mechanism were studied of the leaching of chalcopyrite with ammonium persulphate in the presence of Ag ions as catalyst. The results showed that Cu recovery of more than 98% was obtained using an initial concentration of ammonium persuphate of 0.50 mol/l, leaching temperature of 368 K, leaching time of 100 minutes, chalcopyrite particle size of - 74 + 58 micrometres, Ag ion concentration of 0.001 mol/l, stirring speed up to 600 r/min and pulp density of 25 g/l. Characterisation of the leach residues showed that the silver ions had become uniformly distributed as silver sulphide and that elemental S was produced during the leach and was also uniformly distributed in the residues. Pyrite in the original concentrate was retained in the residues, indicating that it was not oxidised and leached with ammonium persulphate. The analysis suggests silver ions react with chalcopyrite to produce silver sulphide which is mixed with the sulphur layer on the product. This reaction strongly enhances the conducting behaviour of the sulphur layer on the chalcopyrite and is a key factor in accelerating the Cu leaching rate.